What is a standard?
A standard is a document that specifies requirements for products, services and/or processes, laying down their required characteristics. This helps ensure the free movement of goods and encourages exports. It serves to safeguard people and goods and to improve quality in all areas of life.

How is it developed?
Standards are developed by those who have a need and an interest in using them. The broad participation of all stakeholders, a transparent development process and the consensus principle ensure the wide acceptance of a standard.

Who develops standards for bearings?
There are several bodies that are recognized throughout the world in terms of bearing standards and nomenclature. They are:

• ABMA/ANSI (American Bearing Manufacturers Association / American National Standards Institute): In the US, ABMA maintains the standards deemed necessary by its bearing industry member companies. This includes revising existing or proposing and preparing new standards. These standards are then recommended to the ANSI for approval as US national standards. ANSI has a committee consisting of representatives from user organizations, manufacturers, and the US government that are devoted to rolling bearing standards activities.
• DIN (Deutsches Institut fur Normung): DIN, the German Institute for Standardization, is the independent platform for standardization in Germany and world over. As a partner for industry, research, and society as a whole, DIN plays a major role to support the marketability of innovative solutions through standardization. Their market-oriented standards and specifications promote global trade, encouraging rationalization, quality assurance and environmental protection as well as improving security and communication.
• JIS (Japanese Industrial Standard): The Japanese Industrial Standards Committee (JISC), Japan’s national standardization body, plays a central role in developing standards in Japan covering a wide range of products and technologies from robots to pictograms.
• ISO (International Organization for Standardization): Through its members, it brings together experts to share knowledge and develop voluntary, consensus-based, market-relevant International Standards that support innovation and provide solutions to global challenges.

Tolerance classes for ball bearings were defined by a committee within the ABMA known as the “Annular Bearings Engineers Committee” (ABEC). These tolerances are commonly referred to as ABEC rating or grade. Tolerance classes for roller bearings are covered by the RBEC classifications contained within the same standard.

The ABEC (and RBEC) tolerance classifications specify both tolerances of size and form for the individual inner and outer rings. The critical features of the rings include the bore (or inner diameter of the inner ring), the outer diameter of the outer ring, the ring widths, and the raceways of each ring. Tolerances of the form include roundness, taper, runout, and parallelism.

There are five classes from largest to smallest tolerances: ABEC 1, ABEC 3, ABEC 5, ABEC 7, and ABEC 9. The higher ABEC classes provide better precision, efficiency, and the possibility of greater speed capabilities, but do not necessarily allow the components to spin faster. The ABEC rating does not specify many critical factors, such as load handling capabilities, ball precision, materials, material Rockwell hardness, degree of ball and raceway polishing, noise, vibration, and lubricant. Due to these factors, an ABEC 3 classified bearing could perform better than an ABEC 7 bearing. Bearings not conforming to at least ABEC 1 cannot be classified as precision bearings as their tolerances are too loose.

The scale also works as a guide for consumers to make informed decisions about the type of bearing they desire, despite not knowing factors related to materials, manufacturing, and performance.

High rated bearings are intended for precision applications like aircraft instruments or surgical equipment. Lower graded bearings are intended for the vast majority of applications such as vehicles, mechanical hobbies, skates, skateboards, fishing reels, and industrial machinery. High ABEC rated bearings allow optimal performance of critical applications requiring very high RPM and smooth operation.

Comparison of Tolerance Classifications of National Standards

Standard	Applicable Standard	Tolerance Class					Bearing Types
American National Standards Institute (ANSI)	ANSI/ABMA Std.20	ABEC-1 / RBEC-1	ABEC-3 / RBEC-3	ABEC-5 / RBEC-5	ABEC-7	ABEC-9	Radial bearings (Except tapered roller bearings)
American Bearing Manufacturer's Association (ABMA)	ANSI/ABMA Std.19.1	Class K	Class N	Class C	Class B	Class A	Tapered roller bearings (Metric series)
	ANSI/ABMA Std.19	Class 4	Class 2	Class 3	Class 0	Class 00	Tapered roller bearings (Inch series)
Deutsches Institut fur Normung (DIN)	DIN 620	P0	P6	P5	P4	P2	All type
Japanese Industrial Standard (JIS)	JIS B 1514	Class 0,6X	Class 6	Class 5	Class 4	Class 2	All type
	ISO 492	Normal class	Class 6	Class 5	Class 4	Class 2	Radial bearings
		Class 6X
International Organization for Standardization (ISO)	ISO 199	Normal Class	Class 6	Class 5	Class 4	ー	Thrust ball bearings
	ISO 578	Class 4	ー	Class 3	Class 0	Class 00	Tapered roller bearings (Inch series)
	ISO 1224	ー	ー	Class 5A	Class 4A	ー	Precision instrument bearings

Table Terminology:
Bearing Tolerances: It refers to three aspects of accuracy:

• Dimensional Accuracy: Dimensional accuracy is a measure of the bearing’s external dimensions, For example, bore diameter (d), outer diameter (D), inner ring width (B), and outer ring width (C). The difference between an actual bearing dimension and the nominal or target value is called the dimensional deviation. The most commonly used measures are the single plane mean bore and outer diameter deviations (Admp and ADmp), and the inner and outer ring width deviations (ABs and ACs). These values are governed by industry standard tolerances. Dimensional accuracy is important for determining shaft and housing fits.
• Machining Accuracy: Machining (or form) accuracy measures the variation in the above example dimensions when a series of measurements is taken on a single bearing and compared to one other. The most common measures are single radial plane bore and outside diameter variation (Vdp and VDp), mean single plane bore and outside diameter variation (Vdmp and VDmp), and inner and outer ring width variation (VBs and VCs). Variation refers to the difference between the largest and smallest measurements in a series, while mean variation refers to the average difference between consecutive measurements.
• Running accuracy: Running accuracy (or runout) is a measure of the degree of eccentricity (for radial runout) and squareness (for bore and O.D. with side face) of the bearing. Inner and outer ring radial runout (Kia and Kea) are the measures most often used. Running accuracy is important to keep excess vibration and misalignment of the assembly at a minimum.

Allowable error limitations for the three areas of bearing accuracy have been internationally standardized for many years as tolerance classes. Each tolerance class specifies a group of limits for all the measures of accuracy (varying in proportion to the bearing size). The most recognized standards are compared in the table above (note that each column represents a set of equivalent classes). For the ISO, JIS, and DiN standards, bearings with standard accuracy are classified as class 0. This is then followed by class 6. From there on, decreasing class numbers denote progressively improving accuracy.

Radial Runout: Radial run-out is the variation of wall thickness in a bearing race. In technical terms, run-out is the measurement of the raceway in which the rolling element rides and how it relates to the outer ring’s outer diameter and the inner ring’s inner diameter as you rotate the bearing 360 degrees. Incorrect run-out can cause a wide variety of issues, depending on the application. For example, if you have a machine designed to create specially aligned holes in a part, incorrect run-out could affect the proper placement of the holes, meaning those holes might not match up with the mating part. In a motor application, you could face issues with vibration or noise.

Table IA

Tolerance Class ABEC-1, RBEC-1
(ISO Class Normal)
Inner Ring

Bore Diameter (d)				Bore Tolerance (Δdmp)		Radial Runout (Kia)	Width Tolerance (ΔBS)		(Tolerance values in 0.0001 inch)
mm		inch					all	single bearing	paired bearings
over	incl.	over	incl.	high	low	max.	high	low
0.6	2.5	0.0236	0.0984	0	-3	4	0	-16	-
2.5	10	0.0984	0.3937	0	-3	4	0	-47	-98
10	18	0.3937	0.7087	0	-3	4	0	-47	-98
18	30	0.7087	1.1811	0	-4	5	0	-47	-98
30	50	1.1811	1.9685	0	-4.5	6	0	-47	-98
50	80	1.9685	3.1496	0	-6	8	0	-59	-150
80	120	3.1496	4.7244	0	-8	10	0	-79	-150
120	180	4.7244	7.0866	0	-10	12	0	-98	-197
180	250	7.0866	9.8425	0	-12	16	0	-118	-197
250	315	9.8425	12.4016	0	-14	20	0	-138	-197
315	400	12.4016	15.7480	0	-16	24	0	-157	-248

Bore Diameter (d)				Bore Tolerance (Δdmp)		Radial Runout (Kia)	Width Tolerance (ΔBS)
mm		inch					all	single bearing	paired bearings
over	incl.	over	incl.	high	low	max.	high	low
0.6	2.5	0.0236	0.0984	0	-8	10	0	-40	-
2.5	10	0.0984	0.3937	0	-8	10	0	-120	-250
10	18	0.3937	0.7087	0	-8	10	0	-120	-250
18	30	0.7087	1.1811	0	-10	13	0	-120	-250
30	50	1.1811	1.9685	0	-12	15	0	-120	-250
50	80	1.9685	3.1496	0	-15	20	0	-150	-380
80	120	3.1496	4.7244	0	-20	25	0	-200	-380
120	180	4.7244	7.0866	0	-25	30	0	-250	-500
180	250	7.0866	9.8425	0	-30	40	0	-300	-500
250	315	9.8425	12.4016	0	-35	50	0	-350	-500
315	400	12.4016	15.7480	0	-40	60	0	-400	-630

Table IB

Tolerance Class ABEC-1, RBEC-1
(ISO Class Normal)
Outer Ring

Outer Diameter (D)				Outer Dia. Tolerance (Δdmp)		Radial Runout (Kea)	Width Tolerance (ΔBS)
mm		inch					all	single bearing	paired bearings
over	incl.	over	incl.	high	low	max.	high	low
2.5	6	0.0984	0.2362	0	-3	6
6	18	0.2362	0.7087	0	-3	6
18	30	0.7087	1.1811	0	-3.5	6
30	50	1.1811	1.9685	0	-4.5	8
50	80	1.9685	3.1496	0	-5	10
80	120	3.1496	4.7244	0	-6	14
120	150	4.7244	5.9055	0	-7	16	Identical to Width Tolerance (ΔBS) of Inner Ring of the same Bearing
150	180	5.9055	7.0866	0	-10	18
180	250	7.0866	9.8425	0	-12	20
250	315	9.8425	12.4016	0	-14	24
315	400	12.4016	15.7480	0	-16	28
400	500	15.7480	19.6850	0	-18	31
500	630	19.6850	24.8031	0	-20	39
630	800	24.8031	31.4961	0	-30	47
800	1000	31.4961	39.3701	0	-39	55

Outer Diameter (D)				Outer Dia. Tolerance (Δdmp)		Radial Runout (Kea)	Width Tolerance (ΔBS)		Tolerance values in micrometers
mm		inch		all				single bearing	paired bearings
over	incl.	over	incl.	high	low	max.	high	low
2.5	6	0.0984	0.2362	0	-8	15
6	18	0.2362	0.7087	0	-8	15
18	30	0.7087	1.1811	0	-9	15
30	50	1.1811	1.9685	0	-11	20
50	80	1.9685	3.1496	0	-13	25
80	120	3.1496	4.7244	0	-15	35	Identical to Width Tolerance (ΔBS) of Inner Ring of the same Bearing
120	150	4.7244	5.9055	0	-18	40
150	180	5.9055	7.0866	0	-25	45
180	250	7.0866	9.8425	0	-30	50
250	315	9.8425	12.4016	0	-35	60
315	400	12.4016	15.7480	0	-40	70
400	500	15.7480	19.6850	0	-45	80
500	630	19.6850	24.8031	0	-50	100
630	800	24.8031	31.4961	0	-75	120
800	1000	31.4961	39.3701	0	-100	140

Table II A

Tolerance Class ABEC-3, RBEC-3
(ISO Class 6)
Inner Ring

Bore Diameter (d)				Bore Tolerance (Δdmp)		Radial Runout (Kia)	Width Tolerance (ΔBS)
mm		inch		all				single bearing	paired bearings
over	incl.	over	incl.	high	low	max.	high	low
0.6	2.5	0.0236	0.0984	0	-3	2	0	-16	-
2.5	10	0.0984	0.3937	0	-3	2.5	0	-47	-98
10	18	0.3937	0.7087	0	-3	3	0	-47	-98
18	30	0.7087	1.1811	0	-3	3	0	-47	-98
30	50	1.1811	1.9685	0	-4	4	0	-47	-98
50	80	1.9685	3.1496	0	-4.5	4	0	-59	-150
80	120	3.1496	4.7244	0	-6	5	0	-79	-150
120	180	4.7244	7.0866	0	-7	7	0	-98	-197
180	250	7.0866	9.8425	0	-8.5	8	0	-118	-197
250	315	9.8425	12.4016	0	-10	10	0	-138	-197
315	400	12.4016	15.7480	0	-16	24	0	-157	-248

Bore Diameter (d)				Bore Tolerance (Δdmp)		Radial Runout (Kia)	Width Tolerance (ΔBS)
mm		inch					all	single bearing	paired bearings
over	incl.	over	incl.	high	low	max.	high	low
0.6	2.5	0.0236	0.0984	0	-7	5	0	-40	-
2.5	10	0.0984	0.3937	0	-7	6	0	-120	-250
10	18	0.3937	0.7087	0	-7	7	0	-120	-250
18	30	0.7087	1.1811	0	-8	8	0	-120	-250
30	50	1.1811	1.9685	0	-10	10	0	-120	-250
50	80	1.9685	3.1496	0	-12	10	0	-150	-380
80	120	3.1496	4.7244	0	-15	13	0	-200	-380
120	180	4.7244	7.0866	0	-18	18	0	-250	-500
180	250	7.0866	9.8425	0	-22	20	0	-300	-500
250	315	9.8425	12.4016	0	-25	25	0	-350	-500
315	400	12.4016	15.7480	0	-30	30	0	-400	-630

Table II B

Tolerance Class ABEC-3, RBEC-3
(ISO Class 6)
Outer Ring

Outer Diameter (D)				Outer Dia. Tolerance (Δdmp)		Radial Runout (Kea)	Width Tolerance (ΔBS)
mm		inch		all				single bearing	paired bearings
over	incl.	over	incl.	high	low	max.	high		low
2.5	6	0.0984	0.2362	0	-3	3	Identical to Width Tolerance (ΔBS) of Inner Ring of the same Bearing
6	18	0.2362	0.7087	0	-3	3
18	30	0.7087	1.1811	0	-3	3.5
30	50	1.1811	1.9685	0	-3.5	4
50	80	1.9685	3.1496	0	-4.5	5
80	120	3.1496	4.7244	0	-5	7
120	150	4.7244	5.9055	0	-6	8
150	180	5.9055	7.0866	0	-7	9
180	250	7.0866	9.8425	0	-8	10
250	315	9.8425	12.4016	0	-10	12
315	400	12.4016	15.7480	0	-11	14
400	500	15.7480	19.6850	0	-13	16
500	630	19.6850	24.8031	0	-20	39
630	800	24.8031	31.4961	0	-18	24
800	1000	31.4961	39.3701	0	-24	30

Outer Diameter (D)	(Metric)			Outer Dia. Tolerance (Δdmp)		Radial Runout (Kea)	Width Tolerance (ΔBS)		Tolerance values in micrometers
mm		inch		all	single bearing		single bearing		paired bearings
over	incl.	over	incl.	high	low	max.	high		low
2.5	6	0.0984	0.2362	0	-7	8	Identical to Width Tolerance (ΔBS) of Inner Ring of the same Bearing
6	18	0.2362	0.7087	0	-7	8
18	30	0.7087	1.1811	0	-8	9
30	50	1.1811	1.9685	0	-9	10
50	80	1.9685	3.1496	0	-11	13
80	120	3.1496	4.7244	0	-13	18
120	150	4.7244	5.9055	0	-15	20
150	180	5.9055	7.0866	0	-18	23
180	250	7.0866	9.8425	0	-20	25
250	315	9.8425	12.4016	0	-25	30
315	400	12.4016	15.7480	0	-28	35
400	500	15.7480	19.6850	0	-33	40
500	630	19.6850	24.8031	0	-38	50
630	800	24.8031	31.4961	0	-45	60
800	1000	31.4961	39.3701	0	-60	75

Table III A

Tolerance Class ABEC-5, RBEC-5
(ISO Class 5)
Inner Ring

Bore Diameter (d)				Bore Tolerance (Δdmp)		Radial Runout (Kia)	Width Tolerance (ΔBS)
mm		inch		all				single bearing	paired bearings
over	incl.	over	incl.	high	low	max.	high		low
0.6	2.5	0.0236	0.0984	0	-2	1.5	0	-16	-98
2.5	10	0.0984	0.3937	0	-2	1.5	0	-16	-98
10	18	0.3937	0.7087	0	-2	1.5	0	-31	-98
18	30	0.7087	1.1811	0	-2.5	1.5	0	-47	-98
30	50	1.1811	1.9685	0	-3	2	0	-47	-98
50	80	1.9685	3.1496	0	-3.5	2	0	-59	-98
80	120	3.1496	4.7244	0	-4	2.55	0	-79	-150
120	180	4.7244	7.0866	0	-5	3	0	-98	-150
180	250	7.0866	9.8425	0	-6	4	0	-118	-197
250	315	9.8425	12.4016	0	-7	5	0	-138	-197
315	400	12.4016	15.7480	0	-9	6	0	-157	-248

Bore Diameter (d)	Metric			Bore Tolerance (Δdmp)		Radial Runout (Kia)	Width Tolerance (ΔBS)		Tolerance values in micrometers
mm		inch		all				single bearing	paired bearings
over	incl.	over	incl.	high	low	max.	high	low
0.6	2.5	0.0236	0.0984	0	-5	4	0	-40	-250
2.5	10	0.0984	0.3937	0	-5	4	0	-40	-250
10	18	0.3937	0.7087	0	-5	4	0	-80	-250
18	30	0.7087	1.1811	0	-6	4	0	-120	-250
30	50	1.1811	1.9685	0	-8	5	0	-120	-250
50	80	1.9685	3.1496	0	-9	5	0	-150	-250
80	120	3.1496	4.7244	0	-10	6	0	-200	-380
120	180	4.7244	7.0866	0	-13	8	0	-250	-380
180	250	7.0866	9.8425	0	-15	10	0	-300	-500
250	315	9.8425	12.4016	0	-18	13	0	-350	-500
315	400	12.4016	15.7480	0	-23	15	0	-400	-630

Table III B

Tolerance Class ABEC-5, RBEC-5
(ISO Class 5)
Outer Ring

Outer Diameter (D)				Outer Dia. Tolerance (Δdmp)		Radial Runout (Kea)	Width Tolerance (ΔBS)
mm		inch		all				single bearing	paired bearings
over	incl.	over	incl.	high	low	max.	high		low
2.5	6	0.0984	0.2362	0	-2	2
6	18	0.2362	0.7087	0	-2	2
18	30	0.7087	1.1811	0	-2.5	2.5
30	50	1.1811	1.9685	0	-3	3
50	80	1.9685	3.1496	0	-3.5	3
80	120	3.1496	4.7244	0	-4	4	Identical to Width Tolerance (ΔBS) of Inner Ring of the same Bearing
120	150	4.7244	5.9055	0	-4.5	4.5
150	180	5.9055	7.0866	0	-5	5
180	250	7.0866	9.8425	0	-6	6
250	315	9.8425	12.4016	0	-7	7
315	400	12.4016	15.7480	0	-8	8
400	500	15.7480	19.6850	0	-9	9
500	630	19.6850	24.8031	0	-11	10
630	800	24.8031	31.4961	0	-14	12

Outer Diameter (D)				Outer Dia. Tolerance (Δdmp)		Radial Runout (Kea)	Width Tolerance (ΔBS)
mm		inch		all				single bearing	paired bearings
over	incl.	over	incl.	high	low	max.	high		low
2.5	6	0.0984	0.2362	0	-5	5	Identical to Width Tolerance (ΔBS) of Inner Ring of the same Bearing
6	18	0.2362	0.7087	0	-5	5
18	30	0.7087	1.1811	0	-6	6
30	50	1.1811	1.9685	0	-6	6
50	80	1.9685	3.1496	0	-9	8
80	120	3.1496	4.7244	0	-10	10
120	150	4.7244	5.9055	0	-11	11
150	180	5.9055	7.0866	0	-13	13
180	250	7.0866	9.8425	0	-15	15
250	315	9.8425	12.4016	0	-18	18
315	400	12.4016	15.7480	0	-20	20
400	500	15.7480	19.6850	0	-23	23
500	630	19.6850	24.8031	0	-28	25
630	800	24.8031	31.4961	0	-35	30

Table IV A

Tolerance Class ABEC-7, RBEC-7
(ISO Class 4)
Inner Ring

Bore Diameter (d)				Bore Tolerance (Δdmp)		Radial Runout (Kia)	Width Tolerance (ΔBS)
mm		inch		all				single bearing	paired bearings
over	incl.	over	incl.	high	low	max.	high		low
0.6	2.5	0.0236	0.0984	0	-1.5	1	0	-16	-98
2.5	10	0.0984	0.3937	0	-1.5	1	0	-16	-98
10	18	0.3937	0.7087	0	-1.5	1	0	-31	-98
18	30	0.7087	1.1811	0	-2	1	0	-47	-98
30	50	1.1811	1.9685	0	-2.5	1.5	0	-47	-98
50	80	1.9685	3.1496	0	-3	1.5	0	-59	-98
80	120	3.1496	4.7244	0	-3	2	0	-79	-150
120	180	4.7244	7.0866	0	-4	2.5	0	-98	-150
180	250	7.0866	9.8425	0	-4.5	3	0	-118	-197

Bore Diameter (d)				Bore Tolerance (Δdmp)		Radial Runout (Kia)	Width Tolerance (ΔBS)		Tolerance values in 0.0001 inch
mm		inch		all				single bearing	paired bearings
over	incl.	over	incl.	high	low	max.	high		low
0.6	2.5	0.0236	0.0984	0	-4	2.5	0	-40	-250
2.5	10	0.0984	0.3937	0	-4	2.5	0	-40	-250
10	18	0.3937	0.7087	0	-4	2.5	0	-80	-250
18	30	0.7087	1.1811	0	-5	3	0	-120	-250
30	50	1.1811	1.9685	0	-6	4	0	-120	-250
50	80	1.9685	3.1496	0	-7	4	0	-150	-250
80	120	3.1496	4.7244	0	-8	5	0	-200	-380
120	180	4.7244	7.0866	0	-10	6	0	-250	-380
180	250	7.0866	9.8425	0	-12	8	0	-300	-500

Table IV B

Tolerance Class ABEC-7, RBEC-7
(ISO Class 4)
Outer Ring

Outer Diameter (D)				Outer Dia. Tolerance (Δdmp)		Radial Runout (Kea)	Width Tolerance (ΔBS)		Tolerance values in 0.0001 inch
mm		inch		all				single bearing	paired bearings
over	incl.	over	incl.	high	low	max.	high	low
2.5	6	0.0984	0.2362	0	-1.5	1
6	18	0.2362	0.7087	0	-1.5	1
18	30	0.7087	1.1811	0	-2	1.5
30	50	1.1811	1.9685	0	-2.5	2
50	80	1.9685	3.1496	0	-3	2
80	120	3.1496	4.7244	0	-3	2.5	Identical to Width Tolerance (ΔBS) of Inner Ring of the same Bearing
120	150	4.7244	5.9055	0	-3.5	3
150	180	5.9055	7.0866	0	-4	3
180	250	7.0866	9.8425	0	-4.5	4
250	315	9.8425	12.4016	0	-5	4.5
315	400	12.4016	15.7480	0	-6	5

Outer Diameter (D)				Outer Dia. Tolerance (Δdmp)		Radial Runout (Kea)	Width Tolerance (ΔBS)
mm		inch		all				single bearing	paired bearings
over	incl.	over	incl.	high	low	max.	high		low
2.5	6	0.0984	0.2362	0	-4	3	Identical to Width Tolerance (ΔBS) of Inner Ring of the same Bearing
6	18	0.2362	0.7087	0	-4	3
18	30	0.7087	1.1811	0	-5	4
30	50	1.1811	1.9685	0	-6	5
50	80	1.9685	3.1496	0	-7	5
80	120	3.1496	4.7244	0	-8	6
120	150	4.7244	5.9055	0	-9	7
150	180	5.9055	7.0866	0	-10	8
180	250	7.0866	9.8425	0	-11	10
250	315	9.8425	12.4016	0	-13	11
315	400	12.4016	15.7480	0	-15	13

Table V A

Tolerance Class ABEC-9, RBEC-9
(ISO Class 2)
Inner Ring

Bore Diameter (d)				Bore Tolerance (Δdmp)		Radial Runout (Kia)	Width Tolerance (ΔBS)		Tolerance values in 0.0001 inch
mm		inch		all				single bearing	paired bearings
over	incl.	over	incl.	high	low	max.	high	low
0.6	2.5	0.0236	0.0984	0	-1	0.5	0	-16	-98
2.5	10	0.0984	0.3937	0	-1	0.5	0	-16	-98
10	18	0.3937	0.7087	0	-1	0.5	0	-31	-98
18	30	0.7087	1.1811	0	-1	1	0	-47	-98
30	50	1.1811	1.9685	0	-1	1	0	-47	-98
50	80	1.9685	3.1496	0	-1.5	1	0	-59	-98
80	120	3.1496	4.7244	0	-2	1	0	-79	-150
120	150	4.7244	5.9055	0	-3	1	0	-98	-150
150	180	5.9055	7.0866	0	-3	2	0	-98	-150
180	250	7.0866	9.8425	0	-3	2	0	-118	-197

Bore Diameter (d)	Metric			Bore Tolerance (Δdmp)		Radial Runout (Kia)	Width Tolerance (ΔBS)		Tolerance values in micrometers
mm		inch		all				single bearing	paired bearings
over	incl.	over	incl.	high	low	max.	high	low
0.6	2.5	0.0236	0.0984	0	-2.5	1.5	0	-40	-250
2.5	10	0.0984	0.3937	0	-2.5	1.5	0	-40	-250
10	18	0.3937	0.7087	0	-2.5	1.5	0	-80	-250
18	30	0.7087	1.1811	0	-2.5	2.5	0	-120	-250
30	50	1.1811	1.9685	0	-2.5	2.5	0	-120	-250
50	80	1.9685	3.1496	0	-4	2.5	0	-150	-250
80	120	3.1496	4.7244	0	-5	2.5	0	-200	-380
120	150	4.7244	5.9055	0	-7	2.5	0	-250	-380
150	180	5.9055	7.0866	0	-7	5	0	-250	-380
180	250	7.0866	9.8425	0	-8	5	0	-300	-500

Table V B

Tolerance Class ABEC-9, RBEC-9
(ISO Class 2)
Outer Ring

Outer Diameter (D)				Outer Dia. Tolerance (Δdmp)		Radial Runout (Kea)	Width Tolerance (ΔBS)
mm		inch		all				single bearing	paired bearings
over	incl.	over	incl.	high	low	max.	high	low
2.5	6	0.0984	0.2362	0	-1	0.5
6	18	0.2362	0.7087	0	-1	0.5
18	30	0.7087	1.1811	0	-1	0.5
30	50	1.1811	1.9685	0	-1.5	1
50	80	1.9685	3.1496	0	-1.5	1.5	Identical to Width Tolerance (ΔBS) of Inner Ring of the same Bearing
80	120	3.1496	4.7244	0	-2	2
120	150	4.7244	5.9055	0	-2	2
150	180	5.9055	7.0866	0	-3	2
180	250	7.0866	9.8425	0	-3	3
250	315	9.8425	12.4016	0	-3	3
315	400	12.4016	15.7480	0	-4	3

Outer Diameter (D)				Outer Dia. Tolerance (Δdmp)		Radial Runout (Kea)	Width Tolerance (ΔBS)		Tolerance values in 0.0001 inch
mm		inch		all				single bearing	paired bearings
over	incl.	over	incl.	high	low	max.	high	low
2.5	6	0.0984	0.2362	0	-2.5	1.5	Identical to Width Tolerance (ΔBS) of Inner Ring of the same Bearing
6	18	0.2362	0.7087	0	-2.5	1.5
18	30	0.7087	1.1811	0	-4	2.5
30	50	1.1811	1.9685	0	-4	2.5
50	80	1.9685	3.1496	0	-4	4
80	120	3.1496	4.7244	0	-5	5
120	150	4.7244	5.9055	0	-5	5
150	180	5.9055	7.0866	0	-7	5
180	250	7.0866	9.8425	0	-8	7
250	315	9.8425	12.4016	0	-8	7
315	400	12.4016	15.7480	0	-10	8