Author: seo@sherbetdonkey.co.uk

When it comes to ball bearings vs roller bearings, there are many similarities and differences. But their overall purpose is to reduce friction and support loads in rotating machinery.

Ball bearings use spherical balls for higher speeds, while roller bearings use shaped rollers to handle heavier loads. The “best” choice all depends on load, speed, space and operating conditions.

WHAT ARE BALL BEARINGS?

Ball bearings are rolling-element components that use spherical balls positioned between inner and outer rings. A cage maintains even spacing between the balls, allowing the rings to rotate smoothly. Their small contact area reduces rolling friction, making them suitable for high-speed applications.

Depending on their design, ball bearings can accommodate radial loads, axial loads or both. Their compact size and versatility make them widely used in electric motors, bicycles, pumps, lawnmowers and household appliances.

TYPES OF BALL BEARINGS

There are several different ball bearing designs, each of which is suited to different environments, loads and operation conditions. They include:

• Deep groove ball bearings are widely used and can support radial and axial loads, with their low-friction design suiting higher-speed applications
• Angular contact ball bearings have raceways arranged at an angle allowing them to support a combination of radial and axial loads
• Loose ball bearings are individual spherical rolling elements that are used in certain assemblies, races and varying mechanical applications
• Self-aligning ball bearings can compensate for a degree of misalignment between the shaft and housing, making them useful where accurate alignment is difficult to maintain
• Thrust ball bearings are intended primarily for axial loads rather than radial loads
• Miniature bearings provide the benefits of ball bearing construction in smaller assemblies where space is limited

WHAT ARE ROLLER BEARINGS?

Roller bearings replace the traditionally spherical balls with rollers. Depending on the bearing design itself these can be cylindrical, barrel-shaped, tapered or long and narrow.

Roller bearings provide a larger contact area between the rolling elements and raceways, distributing loads more effectively than ball bearings. This makes them ideal for heavy-duty applications.

Their load capacity depends on the bearing design, with different types supporting radial loads, axial loads or both.

Common uses include industrial machinery, gearboxes, conveyors and agricultural equipment that require reliable performance under demanding operating conditions.

TYPES OF ROLLER BEARINGS

When looking at roller bearings as an option, you can decide between:

• Cylindrical roller bearings that use straight cylindrical rollers that offer high radial and load capacity across different axial locations and conditions
• Tapered roller bearings use tapered rollers and raceways that make them ideal for carrying a combination of radial and axial loads
• Spherical roller bearings use barrel-shaped rollers that can accommodate heavy loads and misalignment between shaft and housing
• Needle roller bearings use long, thin rollers that are best used in areas where space is at a premium but substantial radial load capacity is needed

KEY DIFFERENCES BETWEEN BALL BEARINGS AND ROLLER BEARINGS

Although they perform similar tasks, ball bearings vs roller bearings have numerous differences outlined in the table below. This information should however be taken as general guidance with true performance depending on a variety of other factors.

Feature	Ball Bearings	Roller Bearings
Rolling element	Spherical Balls	Cylindrical, tapered, spherical or needle shaped rollers
Raceway contact	Smaller point type contact	Larger line type contact
Load capacity	Lower due to size	Higher due to size
Operating speed	Suited for higher speeds	Often suited for heavier loads at lower speeds but some can be used at high speeds
Friction	Low due to smaller contact area	Varies by design but are generally higher
Typical uses	Motors, appliances, bicycles, pumps and machinery	Gearboxes, industrial equipment, agriculture and conveyors

LOAD CAPACITY

Ball bearings contact raceways over a small area, while rollers distribute forces across a wider surface, generally supporting heavier loads. Capacity depends on bearing design and load direction. Check manufacturer ratings to ensure the bearing suits the application.

SPEED AND FRICTION

Ball bearings typically generate less rolling friction, making them suitable for high-speed applications. Roller bearings generally support heavier loads but may create more friction. However, speed limits vary with design, lubrication, load, temperature and bearing size.

DURABILITY AND MAINTENANCE

Bearing durability depends on correct selection, lubrication and operating conditions, not simply bearing type. Excessive loads, contamination, misalignment and heat can shorten service life.
You should always follow manufacturer recommendations for inspection, maintenance and replacement to ensure reliable performance.

APPLICATIONS OF BALL BEARINGS AND ROLLER BEARINGS

Both bearing families are used across automotive equipment, manufacturing, agriculture and general machinery. Although their applications can overlap, the final choice is determined by individual requirements.

An electric motor, for example, often benefits from the low friction and speed capability of a ball bearing. Deep groove ball bearings are commonly used for this type of application.

Heavy industrial machinery may place much greater radial loads on a bearing. Cylindrical or spherical roller bearings are typically better suited where higher load capacity is required.

Gearboxes can use either ball or roller bearings depending on the forces involved. A tapered roller bearing may be selected where combined radial and axial loading is present, while other gearbox designs can use ball bearings or cylindrical rollers.

Agricultural machinery also uses both types, with the correct bearing depending on factors like load, speed, contamination, shock and available space.

BALL BEARINGS VS ROLLER BEARINGS: WHICH SHOULD YOU CHOOSE?

Ball bearings are often the most ideal option for applications in need of high speed and low friction operations under moderate loads. Roller bearings on the other hand are better suited to heavy loads at lower speeds. The exact choice will all depend on different operating requirements, including:

• Load size and direction
• Required speed
• Available space and shaft dimensions
• Alignment
• Lubrication needs
• Temperature, contamination and maintenance options

When looking at replacements for your equipment, you should check the designation, dimension and manufacturer recommendation for the right bearing.

Here at The Bearing Company, we have over half a century of experience in supplying bearings and other engineering essentials adhering to ISO 9001 certification. With competitive pricing, expert service, next day delivery options and free UK shipping on orders over £50, we have cemented ourselves as the industry leader in bearing needs.

Shop our wide range of bearings today or contact the team for further guidance on making your decision.

An ISO tolerance chart provides a standard method for controlling dimensional variation of manufactured components. They are particularly important where parts must fit together accurately and for determining whether a fit is loose, sliding, tight or transitional.

The ISO 286 system uses letters and numbers as specific codes that define the position and sizes of tolerance zones. Although seeing codes like “H7, g6 or p6” may seem complicated at first, once their meanings are understood they actually become perfectly straightforward.

The experts here at The Bearing Company understand the need for clarity, and have compiled this guide on how to read and apply ISO tolerance charts.

UNDERSTANDING ISO TOLERANCES AND FITS

Manufactured components cannot be produced to perfectly exact dimensions, so engineers must specify if a nominal size falls within an acceptable range of tolerance. As an example, a 30 mm shaft will have an ISO tolerance of permitted variations.

ISO tolerance classes work by combining both a letter and a number, with lower-case letters applying to shafts while upper-case letters apply to holes. The letters themselves define tolerance zone positioning with the number indicating width.

This standardised system was put into place to help manufacturers specify components on a consistent level to achieve perfect fits between various mating parts of different brands. They apply to bearings, shafts and housings which require tolerances to be correct for continued reliable performance.

HOW TO FIND THE RIGHT FIT

Reading an ISO tolerance chart becomes far easier when you work through it bit by bit by using the nominal size, tolerance class, upper and lower deviations.

1. FIND YOUR NORMAL SIZE

Start off by identifying the nominal (basic) dimension that is either specified in the component documentation or engineering drawing. This is the starting point for working out applicable ISO tolerances.

As an example – a shaft with a specified diameter of 35 mm has a nominal size of 35 mm. The actual manufactured diameter may differ slightly from this figure as long as it remains in the limits of its assigned tolerance.

ISO tolerance tables divide dimensions into defined size ranges. A 35 mm shaft therefore falls within the relevant range covering that dimension, which is then used to establish the permitted tolerance.

2. CHOOSE YOUR TOLERANCE CLASS

The next step is to identify the tolerance class either for the shaft or hole.

Codes such as g6, h6, k6 and p6 refer to shaft tolerances because they use lower-case letters. Codes such as H7, H8 and H11 apply to holes.

The letter shows where the permitted tolerance zone sits in relation to the nominal dimension.

The number shows the tolerance grade and therefore the width of the acceptable dimensional range.

A lower grade number generally represents a narrower tolerance band than a higher number for the same nominal size.

3. READ THE TOLERANCE VALUES

Once the nominal size has been matched up with the correct tolerance class, the chart will then give you two deviations from the nominal dimension itself.

These deviations will be expressed in micrometres written as µm. For further clarification 1 µm is equal to 0.001 mm.

Positive numbers will place a limit above the nominal dimensions while negative numbers place it below, with certain designs sitting across the nominal size.

As an example, a 30 mm h6 shaft has an upper deviation of 0 µm and a lower deviation of -13 µm. This results in a permitted diameter between 29.987 mm and 30.000 mm.

4. DETERMINE THE FIT

A “fit” is determined by combining the tolerances of two mating components. The three common options are:

Clearance fit: Even at limits of tolerance, the shaft is smaller than the hole leaving a gap between components

Interference fit: When the shaft is larger than the hole, meaning force, temperature control or another fitting method is needed

Transition fit: Tolerance ranges overlap so finished components either result in slight clearance or interference

As an example – a combination of H7 and k6 is treated as a transition fit as the two zones overlap throughout every dimension.

5. CHECK THE CLEARANCE DESCRIPTION

If you are aware of the type of fit required, then use the ISO clearance description table to narrow down the range of suitable hole and shaft combinations. Then check this against the tolerance values for your nominal size.

These descriptions should only be used as guidance, actual clearance varies by size, the application of the bearing itself and various other levels of operational requirements. For further clarification, contact one of our experts today.

ISO TOLERANCE CHART

ISO SHAFT TOLERANCES

ISO Tolerances for Shafts
Nominal Shaft Sizes (mm)
over	3	6	10	18	30	40	50	65	80	100	120	140	160	180	200	225	250	280	315	355
including	6	10	18	30	40	50	65	80	100	120	140	160	180	200	225	250	280	315	355	400
Micrometres
a12	-270 -390	-280 -430	-290 -470	-300 -510	-310 -560	-320 -570	-340 -640	-360 -660	-380 -730	-410 -760	-460 -860	-520 -920	-580 -980	-660 -1120	-740 -1200	-820 -1280	-920 -1440	-1050 -1570	-1200 -1770	-1350 -1920
d6	-30 -38	-40 -49	-50 -61	-65 -78	-80 -96		-100 -119		-120 -142		-145 -170			-170 -199			-190 -222		-210 -246
e6	-20 -28	-25 -34	-32 -43	-40 -53	-50 -66		-60 -79		-72 -94		-85 -110			-100 -129			-110 -142		-125 -161
e13	-20 -200	-25 -245	-32 -302	-40 -370	-50 -440		-60 -520		-72 -612		-85 -715			-100 -820			-110 -920		-125 -1015
f5	-10 -15	-13 -19	-16 -24	-20 -29	-25 -36		-30 -43		-36 -51		-43 -61			-50 -70			-56 -79		-62 -87
f6	-10 -18	-13 -22	-16 -27	-20 -33	-25 -41		-30 -49		-36 -58		-43 -48			-50 -79			-56 -88		-62 -98
f7	-10 -22	-13 -28	-16 -34	-20 -41	-25 -50		-30 -60		-36 -71		-43 -83			-50 -96			-56 -108		-62 -119
g5	-4 -9	-5 -11	-6 -14	-7 -16	-9 -20		-10 -23		-12 -27		-14 -32			-15 -35			-17 -40		-18 -43
g6	-4 -12	-5 -14	-6 -17	-7 -20	-9 -25		-10 -29		-12 -34		-14 -39			-15 -44			-17 -49		-18 -54
g7	-4 -16	-5 -20	-6 -24	-7 -28	-9 -34		-10 -40		-12 -47		-14 -54			-15 -61			-17 -69		-18 -75
h4	-0 -4	-0 -4	-0 -5	-0 -6	-0 -7		-0 -8		-0 -10		-0 -12			-0 -14			-0 -16		-0 -18
h5	-0 -5	-0 -6	-0 -8	-0 -9	-0 -11		-0 -13		-0 -15		-0 -18			-0 -20			-0 -23		-0 -25
h6	-0 -8	-0 -9	-0 -11	-0 -13	-0 -16		-0 -19		-0 -22		-0 -25			-0 -29			-0 -32		-0 -36
h7	-0 -12	-0 -15	-0 -18	-0 -21	-0 -25		-0 -30		-0 -35		-0 -40			-0 -46			-0 -52		-0 -57
h8	-0 -18	-0 -22	-0 -27	-0 -33	-0 -39		-0 -46		-0 -54		-0 -63			-0 -72			-0 -81		-0 -89
h9	-0 -30	-0 -36	-0 -43	-0 -52	-0 -62		-0 -74		-0 -87		-0 -100			-0 -115			-0 -130		-0 -140
h10	-0 -48	-0 -58	-0 -70	-0 -84	-0 -100		-0 -120		-0 -140		-0 -160			-0 -185			-0 -210		-0 -230
h11	-0 -75	-0 -90	-0 -110	-0 -130	-0 -160		-0 -190		-0 -220		-0 -250			-0 -290			-0 -320		-0 -360
h12	-0 -120	-0 -150	-0 -180	-0 -210	-0 -250		-0 -300		-0 -350		-0 -400			-0 -460			-0 -520		-0 -570
j5	1	2	2	1	1		-1		-3		-4			-6			-9		-11
j6	4	5	5	5	6		5		4		3			3			0		0
j7	4	5	6	5	5		6		5		4			4			0		1
js5	0	0	0	0	0		0		0		0			0			0		0
js6	0	0	0	0	0		0		0		0			0			0		0
js7	0	0	0	0	0		0		0		0			0			0		0
k5	7	8	10	13	15		17		21		24			28			31		33
k6	10	11	13	17	20		23		28		31			37			40		44
k7	14	17	20	25	29		34		41		46			54			60		65
m5	13	18	22	25	29		35		41		48			54			63		67
m6	16	21	25	29	34		41		48		55			63			72		78
m7	20	27	32	37	43		52		61		70			80			92		99
n5	21	26	32	39	45		53		61		72			82			91		99
n6	24	29	35	43	50		59		68		79			91			100		110
n7	28	35	42	51	59		70		81		94			108			120		131
p5	29	36	44	53	63		77		89		104			120			135		149
p6	32	39	47	57	68		83		96		111			129			144		160
r6	38	47	57	69	84		101	105	124	130	151	155	161	183	189	197	220	228	252	264

ISO HOLE TOLERANCES

ISO Tolerances for Holes
Nominal Shaft Sizes (mm)
over	3	6	10	18	30	40	50	65	80	100	120	140	160	180	200	225	250	280	315	355
including	6	10	18	30	40	50	65	80	100	120	140	160	180	200	225	250	280	315	355	400
Micrometres
E6	+28 +20	+34 +25	+43 +32	+53 +40	+66 +50		+79 +60		+94 +72		+110 +85			+129 +100			+142 +110		+161 +125
E7	+32 +20	+40 +25	+50 +32	+61 +40	+75 +50		+90 +60		+107 +72		+125 +85			+146 +100			+162 +110		+185 +125
E11	+95 +20	+115 +25	+142 +32	+170 +40	+210 +50		+250 +60		+292 +72		+335 +85			+390 +100			+430 +110		+485 +125
E12	+140 +20	+175 +25	+212 +32	+250 +40	+300 +50		+360 +60		+422 +72		+485 +85			+560 +100			+630 +110		+695 +125
E13	+200 +20	+245 +25	+302 +32	+370 +40	+440 +50		+520 +60		+612 +72		+715 +85			+820 +100			+920 +110		+1015 +125
F6	+18 +10	+22 +13	+27 +16	+33 +20	+41 +25		+49 +30		+58 +36		+68 +43			+79 +50			+88 +56		+98 +62
F7	+22 +10	+28 +13	+34 +16	+41 +20	+50 +25		+60 +30		+71 +36		+83 +43			+96 +50			+108 +56		+119 +62
F8	+28 +10	+35 +13	+43 +16	+53 +20	+64 +25		+76 +30		+90 +36		+106 +43			+122 +50			+137 +56		+151 +62
G6	+12 +4	+14 +5	+17 +6	+20 +7	+25 +9		+29 +10		+34 +12		+39 +14			+44 +15			+49 +17		+54 +18
G7	+16 +4	+20 +5	+24 +6	+28 +7	+34 +9		+40 +10		+47 +12		+54 +14			+61 +15			+69 +17		+75 +18
G8	+22 +4	+27 +5	+33 +6	+40 +7	+48 +9		+56 +10		+66 +12		+77 +14			+87 +15			+98 +17		+107 +18
H6	+8 0	+9 0	+11 0	+13 0	+16 0		+19 0		+22 0		+25 0			+29 0			+32 0		+36 0
H7	+12 0	+15 0	+18 0	+21 0	+25 0		+30 0		+35 0		+40 0			+46 0			+52 0		+57 0
H8	+18 0	+22 0	+27 0	+33 0	+39 0		+46 0		+54 0		+63 0			+72 0			+81 0		+89 0
H9	+30 0	+36 0	+43 0	+52 0	+62 0		+74 0		+87 0		+100 0			+115 0			+130 0		+140 0
H10	+48 0	+58 0	+70 0	+84 0	+100 0		+120 0		+140 0		+160 0			+185 0			+210 0		+230 0
H11	+75 0	+90 0	+110 0	+130 0	+160 0		+190 0		+220 0		+250 0			+290 0			+320 0		+360 0
J6	+5 -3	+5 -4	+6 -5	+8 -5	+10 -6		+13 -6		+16 -6		+18 -7			+22 -7			+25 -7		+29 -7
J7	+6 -6	+8 -7	+10 -8	+12 -9	+14 -11		+18 -12		+22 -13		+26 -14			+30 -16			+36 -16		+39 -18
J8	+10 -8	+12 -10	+15 -12	+20 -13	+24 -15		+28 -18		+34 -20		+41 -22			+47 -25			+55 -26		+60 -29
JS6	+4 -4	+4.5 -4.5	+5.5 -5.5	+6.5 -6.5	+8 -8		+9.5 -9.5		+11 -11		+12.5 -12.5			+14.5 -14.5			+16 -16		+18 -18
JS7	+6 -6	+7.5 -7.5	+9 -9	+10.5 -10.5	+12.5 -12.5		+15 -15		+17.5 -17.5		+20 -20			+23 -23			+26 -26		+28.5 -28.5
JS8	+9 -9	+11 -11	+13.5 -13.5	+16.5 -16.5	+19.5 -19.5		+23 -23		+27 -27		+31.5 -31.5			+36 -36			+40.5 -40.5		+44.5 -44.5
K6	+2 -6	+2 -6	+2 -9	+2 -11	+3 -13		+4 -15		+4 -18		+4 -21			+5 -24			+5 -27		+7 -29
K7	+3 -9	+5 -10	+6 -12	+6 -15	+7 -18		+9 -21		+10 -25		+12 -28			+13 -33			+16 -36		+17 -40
K8	+5 -13	+6 -16	+8 -19	+10 -23	+12 -27		+14 -32		+16 -38		+20 -43			+22 -50			+25 -56		+28 -61
M6	-1 -9	-3 -12	-4 -15	-4 -17	-4 -20		-5 -24		-6 -28		-8 -33			-8 -37			-9 -41		-10 -46
M7	0 -12	0 -15	0 -18	0 -21	0 -25		0 -30		0 -35		0 -40			0 -46			0 -52		0 -57
M8	+2 -16	+1 -21	+2 -25	+4 -29	+5 -34		+5 -41		+6 -48		+8 -55			+9 -63			+9 -72		+11 -78
N6	-5 -13	-7 -16	-9 -20	-11 -24	-12 -28		-14 -33		-16 -38		-20 -45			-22 -51			-25 -57		-26 -62
N7	-4 -16	-4 -19	-5 -23	-7 -28	-8 -33		-9 -39		-10 -45		-12 -52			-14 -60			-14 -66		-16 -73
N8	-2 -20	-3 -25	-3 -30	-3 -36	-3 -42		-4 -50		-4 -58		-4 -67			-5 -77			-5 -86		-5 -94
P6	-9 -17	-12 -21	-15 -26	-18 -31	-21 -37		-26 -45		-30 -52		-36 -61			-41 -70			-47 -79		-51 -87
P7	-8 -20	-9 -24	-11 -29	-14 -35	-17 -42		-21 -51		-24 -59		-28 -68			-33 -79			-36 -88		-41 -98
P8	-12 -30	-15 -37	-18 -45	-22 -55	-26 -65		-32 -78		-37 -91		-43 -106			-50 -122			-56 -137		-62 -151
R6	-12 -20	-16 -25	-20 -31	-24 -37	-29 -45		-35 -54	-37 -56	-44 -66	-47 -69	-56 -81	-58 -83	-61 -86	-68 -97	-71 -100	-75 -104	-85 -117	-89 -121	-97 -133	-103 -139
R7	-11 -23	-13 -28	-16 -34	-20 -41	-25 -50		-30 -60	-32 -62	-38 -73	-41 -76	-48 -88	-50 -90	-53 -93	-60 -106	-63 -109	-67 -113	-74 -126	-78 -130	-87 -144	-93 -150

CLEARANCE DESCRIPTIONS

Description	Hole Tolerance	Shaft Tolerance
Loose fit	H11	c11
Free running	H9	d9
Easy running	H8	f8
Sliding fit	H7	g6
Close clearance	H8	f7
Location clearance	H7	h6
Slight interference	H7	k6
Transition	H7	n6
Press fit	H7	p6
Medium fit	H7	s6
Force fit	H7	u6

SHOP BEARINGS AT THE BEARING COMPANY

Once you have worked out the dimensions and fit required for your application from the ISO tolerance chart, finding the associated bearing size should be straightforward.

Here at The Bearing Company, we have more than 50 years of experience in the supplying of an extensive range of bearings for large engineering projects, domestic repairs and ongoing industrial goals. Whether you need linear ball bearings, bearing inserts and thrust bearings just to name a few.

If you know what you need, shop bearings online now with competitive prices and free shipping on orders over £50 with next day delivery where available. If you are still working out the right bearing, size or specification, get in touch with our team and we will help where we can.

Where are the bearings on a bike? Well, you’ll find them where there are any parts that need to rotate or move smoothly, including the wheel hubs, bottom bracket, headset and pedals. Depending on the bike, bearings can also appear in suspension pivots, derailleur pulleys and other moving components.

That’s the quick answer, but it’s important to remember that different parts use different types of bearing, each suited to their particular loads, movements and the available space on the bike. Below, we’ll break down why bike bearings matter, the main types you may come across and how to keep them in good condition for as long as possible.

WHY ARE BEARINGS ESSENTIAL ON A BIKE?

Put simply, bearings reduce friction between moving parts while supporting the loads that are placed on them. On a bike, they help your wheels spin, cranks turn, handlebars steer and pedals rotate without any unnecessary resistance.

Without them, moving surfaces would rub directly against each other, increasing friction and wear. Using the right bearing for each job keeps movement smooth while helping protect the surrounding components.

Here at The Bearing Company, we stock a wide range of bike and cycling bearings for repairs, replacements and ongoing maintenance.

TYPES OF BEARINGS USED ON A BIKE

The type you need to fit depends on the component and bike design, with loose balls, bushings, cartridge bearings and needle bearings used for different parts of the cycle.

LOOSE BALL BEARINGS

Loose ball bearings are individual steel balls that run between smooth bearing surfaces, usually in a cup-and-cone arrangement. They have been used on bicycles for decades and are still common in wheel hubs, headsets and some bottom brackets and pedals.

Their size is measured by the diameter of the ball itself and is often stated as a fraction of an inch, such as 3/16 in. Replacement balls need to match the originals or the manufacturer’s specification, so always measure carefully and never rely on guesswork.

Explore our range of loose ball bearings for the different sizes we have available.

Ball bearings are found in everything from household appliances and bicycles to cars, agricultural equipment and heavy industrial machinery. Their job is relatively simple: reduce friction between moving parts so equipment can rotate smoothly, efficiently and reliably.

But what is a ball bearing, how does it actually work and how do different types suit different applications? In this guide, the experts here at The Bearing Company will explain their basic construction, common types of ball bearings, typical uses for them and the different sizes and materials available, helping you understand what to look for when choosing the right bearing. Let’s crack on and, if you need help at any point, remember you can always get in touch with us for expert advice, whichever type of bearing you need.

WHAT IS A BALL BEARING?

Put simply, a ball bearing is a type of rolling-element bearing that uses small balls, often made of steel, to reduce friction between two moving surfaces. Rather than those surfaces rubbing or sliding directly against each other, the balls roll between them, allowing rotational movement with much less resistance.

This makes ball bearings useful wherever shafts, wheels, motors or other components need to rotate smoothly while supporting a load. Different designs can handle radial loads, axial loads or a combination of the two.

Here at The Bearing Company, we stock a wide range of ball bearings covering everything from everyday replacements to highly specialist industrial parts.

HOW BALL BEARINGS WORK

The two rings that the balls run between are called the inner and outer races, while the grooves on those rings are called raceways. Most ball bearings consist of an inner race, outer race, a series of balls and a cage or retainer that keeps the balls evenly spaced. The inner race normally fits around a rotating shaft, while the outer race sits within the surrounding housing.

As the shaft turns, the balls roll between the two races rather than allowing the surfaces to slide against one another. This greatly reduces friction, helping equipment move more freely while limiting heat and wear. Bearings are often lubricated too, further reducing friction and heat.

Depending on the design, bearings may also include seals or shields to help keep lubricant inside and contaminants such as dirt, dust or moisture out.

TYPES OF BALL BEARINGS AND HOW THEY WORK

Different applications (such as lawn mowers, bicycles and conveyor systems) place very different demands on their bearings, which is why there are several types available.

ANGULAR CONTACT BEARINGS

Angular contact bearings are designed so the balls contact the races at an angle. This allows them to support combined radial and axial loads, making them useful in equipment where forces act in more than one direction.

We stock both single row angular contact bearings and double row angular contact bearings for different load and space requirements.

THRUST AND AXIAL BEARINGS

Thrust bearings, also known as axial bearings, are designed primarily to support loads acting along the direction of a shaft rather than across it. They are commonly used where rotating components experience significant axial force, such as in gearboxes.

Our range of thrust bearings includes numerous sizes and types for both industrial and everyday machinery.

DEEP GROOVE BEARINGS

Deep groove bearings are among the most widely used bearing types. Their deep raceway grooves allow them to handle radial loads while also supporting moderate axial loads in either direction.

Their simple, versatile design makes deep groove ball bearings suitable for applications including electric motors, washing machines, power tools, bicycles and conveyor systems.

SELF-ALIGNING BEARINGS

Self-aligning ball bearings are designed to accommodate minor misalignment between the shaft and housing. Essentially, the inner assembly can move slightly within the outer race without placing excessive stress on the bearing.

This makes them particularly useful when shafts can bend slightly or when parts are not perfectly aligned, which can happen at installation and over time.

LINEAR BEARINGS

Unlike bearings designed mainly for rotation, linear ball bearings help components travel smoothly along a straight shaft or rail. The internal balls reduce friction during this back-and-forth movement.

They are commonly found in automation, manufacturing equipment, CNC machinery and other systems requiring highly accurate linear motion.

KEY APPLICATIONS OF BALL BEARINGS

Because they help to significantly reduce friction while supporting moving loads, ball bearings are used across an enormous range of sectors and machinery. Just some of the most common applications include:

• Automotive: Used in wheels, electric motors and transmission systems to support smooth rotation.
• Manufacturing: Found in production machinery, conveyors and automated equipment where reliable movement is essential.
• Agriculture: Used in tractors, implements and processing machinery exposed to regular heavy-duty use.
• Electric Motors: Support rotating shafts at speed while helping reduce friction and wear.
• Household Equipment: Common in appliances, power tools and garden machinery with moving internal parts.
• Cycling: Used in wheels, pedals and steering components to keep movement smooth and controlled.
• Industrial Machinery: Found in pumps, fans, compressors and gear systems across a wide range of sectors.

The correct bearing for your specific application depends on many variables, including speed, load direction, working environment and available space.

BALL BEARING SIZES, SHAPES AND MATERIALS

Ball bearings are produced in a huge range of dimensions to suit different shafts, housings and load requirements. Measurements normally include the internal bore diameter, outside diameter and bearing width, so matching the correct specification is important. If you need any assistance with this, we’re here to help.

Standard deep groove bearing series include 6000 bearings, 6200 bearings and 6300 bearings, providing different combinations of internal diameter, external size and load capacity. Material also matters. Steel is widely used because of its strength and durability, while stainless steel ball bearings offer additional corrosion resistance for demanding or moisture-prone environments. We also stock specialist designs such as magneto bearings, which are commonly used in small magnetos, gyroscopes, instruments and vintage engines.

Replacing an existing bearing? The bearing number stamped onto the component is usually the best starting point for identifying the right replacement.

BALL BEARINGS AT THE BEARING COMPANY

We hope this article helped break down exactly what a ball bearing is and demystified how different types work. With so many different types, sizes and applications available, choosing the right bearing can feel complicated, but understanding the basics makes that process much easier.

With more than 50 years of industry experience, The Bearing Company confidently supplies bearings of many different types for everyone from individual DIY customers to large engineering, manufacturing and industrial businesses. We stock a vast selection at competitive prices and specialise in helping customers track down harder-to-find and obsolete parts. We’re also ISO 9001 certified, offer a fast response to enquiries and provide free shipping on orders over £50, with next-day delivery available when you need parts quickly.

Browse our full range of ball bearings and shop online today. If you’re unsure which bearing you need, just get in touch with our team and we’ll help you find the right part for your application.

Thrust bearings vs ball bearings is not a straightforward discussion. Both are essential components used to support moving machinery, but they are designed to handle different types of loads. Understanding these differences can help you choose the right bearing for a specific application.

Our expert engineers have compiled this article to compare thrust bearings and ball bearings, exploring their designs, load capacities, applications, advantages and limitations. We’ll also provide a more detailed breakdown of how each bearing performs under different operating conditions.

WHAT IS A THRUST BEARING?

A thrust bearing is a form of rotary bearing that has been designed with the intention of providing support to axial (thrust) loads. They act as a centralised cage with internal ball bearings and two washers or ‘raceways’ either side.

They manage systems where forces are running parallel to the shaft rather than perpendicular with it. By redirecting created force along the rotational axis of a shaft they can reduce friction and better distribute weight and pressure caused by pushing.

BENEFITS OF THRUST BEARINGS

There are many benefits to thrust bearings, crucially they are designed to prevent shaft drifting lengthways during smooth rotational movement. They are ideal for light-to-moderate loads that are performing at high speeds but require minimal created friction and total shaft stability.

WHAT IS A BALL BEARING?

When looking at the key differences with thrust bearings vs ball bearings, the latter are arguably the most commonly found component in engineering, machinery and any other piece of equipment. They are composed of an inner ring, outer ring, smaller ball bearings and a cage. The ball bearings find themselves placed between the two rings, also known as races, to prevent two flat surfaces rubbing against each other, creating needless wear and tear from friction.

BENEFITS OF BALL BEARINGS

There are several benefits offered by ball bearings which include, reducing friction levels, ensuring smooth operations and efficient movement between components. They tend to have a relatively compact design which makes them suitable and essential for a wide range of applications. Arguably their biggest benefit is that, depending on the design, they can support both radial and axial loads while also helping reduce wear and overall operational energy consumption.

THRUST BEARINGS VS BALL BEARINGS

BEARING DESIGN

Thrust bearings are designed to primarily support axial loads which makes them the more suitable option for applications where force acts along the shaft. Ball bearings on the other hand typically handle radial loads for rotating machinery.

INTERNAL COMPONENTS

Both of these bearing types use balls, raceways and cages but their internal arrangements do differ. Ball bearings position components to support radial movement, while thrust bearings use races arranged to accommodate axial forces. This design difference determines how each bearing performs within machinery.

LOAD DIRECTION & CONTACT ANGLE

Ball bearings primarily support radial loads, although angular-contact designs can accommodate axial forces. Thrust bearings are specifically designed for axial loads. Their contact geometry directs force along the shaft, making them better suited to applications experiencing significant thrust forces.

MATERIALS AND MAINTENANCE

Both bearing types are commonly manufactured from materials like steel, stainless steel or a different, more specialised material for demanding applications. Regular lubrication, cleaning and inspection will greatly help extend service life.

HOW TO CHOOSE THE RIGHT BEARING FOR YOUR APPLICATION

Choosing the right kind of bearing depends on numerous factors outside of simply thrust bearing vs ball bearing. You first need to take into account your load type, total capacity, temperature, lubrication needs, available space, operating speed and surrounding working environment.

Then you need to consider whether your proposed/required application is radial, axial or a combination in nature. If you are uncertain about which bearing is the most suitable for you, The Bearing Company experts are here to help. By contacting our team we can offer advice to help you find the right solution.

WHY CHOOSE THE BEARING COMPANY?

The Bearing Company offers a wide range of quality bearings for various applications and requirements. Alongside ball and thrust bearings, our selection includes needle roller bearings, linear bearings, taper roller bearings, bearing inserts and housed bearings. With a comprehensive range and industry leading advice available, finding the right solution with The Bearing Company is simple.

Explore our bearing collection today and choose The Bearing Company for quality products and dependable service.

Finding the right bearing for your application can feel overwhelming, with a wide range of options to choose from. Picking the right bearing sizes for your project doesn’t need to be a challenge — our simple guide makes it straightforward. From ball bearings to thrust bearings, we cover the full range to make it easy for you to select the right option with confidence.

WHAT IS A BEARING?

Bearings are an essential component utilised in a wide range of different applications, from automotive and industrial machinery to household appliances and medical equipment . These essential components help to constrain movement while reducing friction, allowing for smooth rotation and reduced wear and tear over time.

Our range at The Bearing Company includes many unique styles of bearing and accompanying parts to suit different applications, from classic ball bearings and linear ball bearings to housed bearing units and additional bearing inserts. We cover the sizes for all of our bearings below.

6000 METRIC

Bearing Size	Inside Diameter (mm)	Outside Diameter (mm)	Width (mm)
6000	10	26	8
6001	12	28	8
6002	15	32	9
6003	17	35	10
6004	20	42	12
6005	25	47	12
6006	30	55	13
6007	35	62	14
6008	40	68	15
6009	45	75	16
6010	50	80	16
6011	55	90	18
6012	60	95	18
6013	65	100	18
6014	70	110	20
6015	75	115	20
6016	80	125	22
6017	85	130	22
6018	90	140	24
6019	95	145	24
6020	100	150	24
6021	105	160	26
6022	110	170	28
6024	120	180	28
6026	130	200	33
6028	140	210	33
6030	150	225	35

6200 METRIC

Bearing Size	Inside Diameter (mm)	Outside Diameter (mm)	Width (mm)
6200	10	30	9
6201	12	32	10
6202	15	35	11
6203	17	40	12
6204	20	47	14
6205	25	52	15
6206	30	62	16
6207	35	72	17
6208	40	80	15
6209	45	85	19
6210	50	90	20
6211	55	100	21
6212	60	110	22
6213	65	120	23
6214	70	125	24
6215	75	130	25
6216	80	140	26
6217	85	150	28
6218	90	160	30
6219	95	170	32
6220	100	180	34
6221	105	190	36
6222	110	200	38
6224	120	215	40
6226	130	230	40
6228	140	250	42
6230	150	270	45

6300 METRIC

Bearing Size	Inside Diameter (mm)	Outside Diameter (mm)	Width (mm)
6300	10	35	11
6301	12	37	12
6302	15	42	13
6303	17	47	14
6304	20	52	15
6305	25	62	17
6306	30	72	19
6307	35	80	21
6308	40	90	23
6309	45	100	25
6310	50	110	27
6311	55	120	29
6312	60	130	31
6313	65	140	33
6314	70	150	35
6315	75	160	37
6316	80	170	39
6317	85	180	41
6318	90	190	43
6319	95	200	45
6320	100	215	47
6321	105	225	49
6322	110	240	50
6324	120	260	55
6326	130	280	58
6328	140	300	62
6330	150	320	65

6800 METRIC

Bearing Size	Inside Diameter (mm)	Outside Diameter (mm)	Width (mm)
6800 (61800)	10	19	5
6801 (61801)	12	21	5
6802 (61802)	15	24	5
6803 (61803)	17	26	5
6804 (61804)	20	32	7
6805 (61805)	25	37	7
6806 (61806)	30	42	7
6807 (61807)	35	47	7
6808 (61808)	40	52	7
6809 (61809)	45	58	7
6810 (61810)	50	65	7
6811 (61811)	55	72	9
6812 (61812)	60	78	10
6813 (61813)	65	85	10
6814 (61814)	70	90	10
6815 (61815)	75	95	10
6816 (61816)	80	100	10
6817 (61817)	85	110	13
6818 (61818)	90	115	13
6819 (61819)	95	120	13
6820 (61820)	100	125	13
6821 (61821)	105	130	13
6822 (61822)	110	140	16
6824 (61824)	120	150	16
6826 (61826)	130	165	18
6828 (61828)	140	175	18
6830 (61830)	150	190	20

6900 METRIC

Bearing Size	Inside Diameter (mm)	Outside Diameter (mm)	Width (mm)
6900 (61900)	10	22	6
6901 (61901)	12	24	6
6902 (61902)	15	28	7
6903 (61903)	17	30	7
6904 (61904)	20	37	9
6905 (61905)	25	42	9
6906 (61906)	30	47	9
6907 (61907)	35	55	10
6908 (61908)	40	62	12
6909 (61909)	45	68	12
6910 (61910)	50	72	12
6911 (61911)	55	80	13
6912 (61912)	60	85	13
6913 (61913)	65	90	13
6914 (61914)	70	100	16
6915 (61915)	75	105	16
6916 (61916)	80	110	16
6917 (61917)	85	120	18
6918 (61918)	90	125	18
6919 (61919)	95	130	18
6920 (61920)	100	140	20
6921 (61921)	105	145	20
6922 (61922)	110	150	20
6924 (61924)	120	165	22
6926 (61926)	130	180	24
6928 (61928)	140	190	24
6930 (61930)	150	210	28

HOW TO MEASURE A BALL BEARING

Typically, a bearing will have an identification code stamped into the outside of the component. This identifier can allow you to look up the size of your bearing from the charts above. However, sometimes this stamp is not legible due to a long period of use, requiring manual measurement to choose the right replacement.

We cover the steps for measuring a bearing below:

PREPARE EQUIPMENT

You’ll need the following to measure your bearing:

• A micrometer or calliper for accurate measurement
• A way to record your results
• A flat, clean and clear surface for completing your measurements

MEASURE THE INNER DIAMETER

To measure the bore size, or inner diameter, place the bearing on a flat, clear surface. Use the calliper or micrometer and insert the jaws or anvils into the open hole in the middle of the bearing, ensuring it is at a right angle. Read and record the measurement.

MEASURE THE OUTER DIAMETER

To measure the outer diameter of your bearing, position your micrometer or calliper flat on a clear surface and place the jaws or anvils on the outer edges of the bearing. Ensure it is at a right angle to the bearing and record the measurement results.

MEASURE THE WIDTH

To measure the width or thickness of the bearing, place the bearing on its edge and then use the anvils or jaws to ‘clamp’ either side of the edge. Record the results of this measurement.

WHY CHOOSE THE BEARING COMPANY

With over 50 years of experience as bearing specialists, The Bearing Company is your ideal option for high-quality bearings, available for next-day delivery. We provide clear sizing information for all of our bearings online, making it easy for you to choose the right option for your needs.

Our comprehensive range includes housed bearings, bearing inserts, cylindrical roller bearings, taper roller bearings, bike bearings and more. Shop the full range online today, with free shipping available for all orders over £50.

Bearings are everywhere. Inside anything that rotates, there is likely a bearing, used to reduce friction and provide smooth movement. But how do bearings work?

In this complete guide, we’re going to break down how bearings work, some of the key components, the different types and the importance of lubricants. Keep scrolling to learn more, or to speak directly to a bearings expert, just call us now on 01527 509620.

WHAT IS A BEARING?

A bearing is designed to support and guide moving parts. They generally allow either rotational or linear movement, minimising friction and wear. Bearings are installed between the two moving components, facilitating easy motion.

There are a few different types of bearing, each designed to support a different kind of movement as well as varying degrees of load and use. Bearings are used in everything from skateboard wheels and children’s toys to vehicles and industrial machinery.

COMPONENTS OF A BEARING

In most bearings, there are four main parts:

• Inner Ring – the inner ring is seated onto the rotating shaft or surface, and moves with it, transferring load into the bearing
• Outer Ring – the outer ring is stationary, and supports the bearing within the equipment it’s mounted to, transferring load out of the bearing to the equipment
• Rolling Elements – these can be balls, needles or rollers, and are designed to allow smooth movement with minimal friction
• Cage (or separator) – the purpose of the cage, sometimes called a separator, is to keep the rolling elements evenly spaced and ensure the load is evenly distributed

HOW DO BEARINGS WORK? THE BASICS

The purpose of a bearing is to allow for low-friction movement of two components, generally between a rotating shaft and a fixed housing. Bearings feature rolling elements, often balls or rollers, which create smooth, low-resistance movement.

They include an inner ring, which sits around the rotating shaft, and an outer ring, which presses against the housing, with the rolling elements sandwiched in between. This spreads the rotational load and makes movement easy, reducing friction and heat build-up.

BEARING LOADS

A bearing load is the rotational force that’s applied to the bearing, which it is designed to support. There are three main types of bearing load:

• Radial loads – act perpendicular to the shaft, found in conveyor rollers, electric motors and hydraulic pumps
• Axial loads – act parallel to the shaft, found in gearboxes, vertical pumps and turntables
• Combined loads – a blend of both radial and axial loads, found in automotive wheel hubs, industrial gear drives and construction machinery

Each kind of load requires a different type of bearing to handle it.

• Radial loads = radial bearings such as deep groove roller bearings and cylindrical bearings
• Axial loads = thrust bearings
• Combination loads = tapered roller bearings and angular contact bearings

TYPES OF BEARINGS

There are many types of bearings, each used for a slightly different application and load type:

• Ball bearings
• Roller bearings
• Cylindrical roller bearings
• Spherical roller bearings
• Tapered roller bearings
• Needle roller bearings
• Thrust bearings
• Angular contact bearings
• Deep groove ball bearings
• Plain bearings
• Slewing bearings
• Magnetic bearings

You can find more information about the different types of bearings and what they’re used for in our blog post.

THE FUNCTION OF ROLLING ELEMENTS

Inside a bearing, there is a collection of rolling elements, which are usually either balls or rollers.

BALLS

Balls are used inside bearings to create smooth, low-friction movement. They create very small contact surfaces, allowing for seamless rotation of the bearing. This makes them ideal for lower-load applications where smoothness and speed are more important, such as in electric motors, pumps and fans.

ROLLERS

Rollers serve the same purpose as balls, but have a larger contact area, allowing them to spread loads over a greater surface. This makes rollers the preferred choice for high-load or heavy impact applications such as heavy plant machinery, manufacturing equipment and agriculture.

THE ROLE OF LUBRICANTS

Lubricants are used inside bearings to further reduce friction, heat and wear. Most bearings use largely or entirely metallic components, and without lubrication, these parts would get hot and worn very quickly. Lubricants extend the lifespan of bearings dramatically, playing a critical role in their construction and ongoing use.

Different types of lubricants are used in various bearings depending on the type and application, including grease, oil and solid lubricants.

BEARINGS AT THE BEARING COMPANY

There is a wide variety of different bearing types, each suited to a selection of applications from skateboards and toys to large-scale machinery. They come in various shapes and sizes but all use a similar underlying principle of rolling components and lubrication.

At The Bearing Company, we make finding the right bearing for your application a breeze. Just use our simple search tools to browse thousands of bearing types and sizes and enjoy free tracked shipping on all orders over £50. If you need speciality bearings, just give us a call.

Shop our huge selection today or for any questions, call us on 01527 509620, email us at sales@thebearingcompany.co.uk or fill out our contact form.