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Bearing Identification System
Cage & Retainer Types
Design & Characteristics of Radial Ball Bearings
Industry Engineering Lube
ABEC Tolerances/ISO Ratings
Internal Clearance
Maximum Permissable Bearing Speed
Bearing Usage
Damage/Cause/Remedy

Engineering Guide

Bearing Identification System

	1	2	3	4	5	6	7	8	9	10
SERIES	Material	Type	Style	Basic Size	Special Feature	Closures	Ring Feature	ABEC Tolerance	Radial Play	Lubrication
METRIC	M	F	-	105	X	ZZ	EE	A3	MC3	LO1
INCH	S	F	R	156	X	ZZ	EE	A3	MC3	LO1

1	Material (M) (S)
	Symbol M or Blank denotes SUJ2 (SAE52100) Chrome Steel. Symbol S denotes SUS440C (AIS1440C) Stainless Steel.
2	Type (F)
	Symbol F is used to designate a Flanged bearing is required.
3	Style (R)
	Symbol R is used for all miniature and instrument bearings to signify Single Row Radial Retainer Type.
4	Basic Size (105) (156)
	Symbol R is used for all miniature and instrument bearings to signify Single Row Radial Retainer Type.
5	Special Features (X)
	Symbol X is used to designate a change in the standard bearing size.
6	Closures (ZZ)
	The following symbols designate available closures. No designation denotes and Open style bearing. Z-Single Shield, RS-Single Rubber Seal, VV-Double Non-Contact Seals ZZ-Double Shield, 2RS-Double Rubber Seals, ZZS-Removable Seals Z1-Shield on Flange Side, Z2-Shield Opposite Flange Side
7	Ring Feature (EE)
	Symbol EE is used when the Extended Inner Rings are required.
8	ABEC Tolerances (A3)
	AFBMA Standards: A1-ABEC1, A3-ABEC3, A5-ABEC5, A7-ABEC7 ISO Standards: P0(A1) P6(A3) P5(A5) P4(A7)
9	Radial Play (MC3)
	Symbol MC3 followed by numbers indicates the range of radial play. Example: MC3=0.005-0.013mm (0.0002 to 0.0005 inch) Example: MC4=0.013-0.020mm (0.0005 to 0.0008 inch) Symbol C designates larger size metric bearings.
10	Lubrication (LO1) - blank denotes manufacturer option
	All bearings supplied with manufacturer's standard lubrication. LO followed by number indicates specific oil lube. LG followed by number indicates specific grease lube. LD denotes dry bearings. For specific lubrication, refer to the Lubrication Guide.

Cage & Retainer Types


W : ONE-PIECE STEEL CROWN TYPE	J : TWO-PIECE STEEL RIBBON TYPE	RJ : TWO-PIECE STEEL RIVET TYPE	TW : ONE-PIECE NYLON CROWN TYPE	V : FULL COMPLEMENT OF BALLS
The stainless steel pressed cage is inner ring guided. It shows excellent performance in low torque, low speed applications	Consists of two mating steel pressings, the cover side and the finger side. Usually guided by the rolling elements and designed to reduce frictional torque.	The RJ type cage is suitable for larger bearings with a high load carrying capacity. The two pieces are riveted together and are strong enough to withstand higher levels of vibration and acceleration. The cage is guided by the balls and reduces frictional torque.	Molded nylon cage. Reduces the fluctuation in running torque. Suitable for high speeds. Guided by the rolling elements.	This type of bearing has no cage but maximum possible number of balls. Due to the fact that the inner and outer ring have a filling slot, the axial load carrying capacity of this bearing type is low. This type of bearing is suitable for high radial load, low speed applications.

Design & Characteristics of Radial Ball Bearings

BEARING STRUCTURE

BEARING DESIGN

Standard	(EE) Extended Inner Ring	(V) Full Complement	(N) With Snap Ring Groove	(NR) With Snap Ring Groove and Snap Ring	(F) With Flanged Outer Ring

BEARING CHARACTERISTICS
Load:	Single row radial ball bearings with ball separated by a cage can support radial loads, axial loads and tilting movements. All full complement V-type ball bearing can support only radial loads and some low axial loads.
Speed:	Maximum permissible speeds for ball bearings are mainly related to the bearing design and size, cage type, bearing internal clearance, the method and type of lubrication, manufacturing accuracy, sealing methods and loads.
Torque & Noise Level:	Single row radial ball bearings are precision components and have low torque and noise levels.
Inclination of Inner/Outer Rings:	Shaft and housing seats with poor accuracy, fitting errors and shaft bending might cause inclination between the inner and outer rings, although the internal clearance of the bearing will permit this to a certain extent. Generally, the maximum permissible inclination between the inner and out rings is approximately 1 in 300.
Toughness:	Bearings under load deform elastically at the contact point between the rolling element and bearing ring. This is influenced by the bearing type, size, form and load.
Installation & Removal	The single row radial ball bearing is a non-separable bearing. Therefore, shafts and housings should be so designated to enable bearing inspection and replacement when necessary.
Axial Location:	Improved axial location is obtained with NR and F type bearings

BEARING DESIGN MATERIAL
Standard material for rings and balls is a vacuum degassed high carbon chromium steel allowing for high efficiency, low torque, low noise level and long bearing life. For bearings requirng anti-corrosion or heat-resistance properties, marensitic stainless steel is used.
CHEMICAL COMPOSITION OF BEARING MATERIAL
Materials	Symbol	Chemical Composition %							Equivalent
Materials	Symbol	C	Si	Mn	P	S	Cr	Mo	Equivalent
High Carbon Chromium Steel	SUJ2	0.95~1.10	0.15~0.35	<=0.50	<=0.025	<=0.025	1.30~1.60	<=0.08	SAE52100
Stainless Steel	SUS440C	0.95~1.20	<=1.00	<=1.00	<=0.040	<=0.030	16.00~18.00	<=0.75	AISI440c


ZZ: Pressed Steel Shield	ZZS Presseed Steel Shield	TTS Teflon Seal w/ Snap Ring	2RS Contact Rubber Seal	Non Contact Rubber Seal
Non-contact shield pressed into outer ring.	Non-contact shield retained in outer ring. (Removable)	Non-contact shield retained in outer ring. (Removable)	Rubber seal fitted into outer ring.	Non-contact rubber seal fitted into outer ring

Industry Engineering Lube

Common Oil Brands and Efficiency

MANUFACTURER	BRAND	OUR CODE	LUBRICATION BASE	FLASH POINT ºC	VISCOSITY	OPERATING TEMP. ºC	MIL STANDARD
SHELL OIL	AERO SHELL FLUID 12*	AF2	DIESTER	235	14(38ºC)	-50 TO +120	MIL-L-6085A
SHELL OIL	AERO SHELL FLUID 3	AF3	PETROLEUM	145	10.2(40ºC)	-55 TO +115	MIL-L-7870A
ANDERSON OIL	WINDSOR LUBE L-245X	WL2	DIESTER	215	14(38ºC)	-55 TO +175	MIL-L-6085A
TENNECO CHEMICALS	ANDERSOLL-401D	A4D	DIESTER	220	12.7(38ºC)	-60 TO +125	MIL-L-6085A
DOW CORNING	SH550R	D5R	METHYLPHENYL	316	125(25ºC)	-40 TO +230	-
NIHON OIL CO.	ANTIRUST P2100	002	-	166	13(40ºC)	-	VV-L-800

Common Grease Brands and Efficiency

MANUFACTURER	BRAND	OUR CODE	THICKENING AGENT	LUBRICATION BASE	DROP PT. ºC	CONSISTENCY	OPERATING TEMP. ºC	MIL STANDARD
SHELL OIL CO.	ALVANIA NO.1	AV2	LITHIUM	MINERAL	182	272	-25 TO +120	MIL-18709
	ALVANIA NO.3	AV3	LITHIUM	MINERAL	183	233	-20 TO +135	-
	ALVANIA RA	AVS	LITHIUM	MINERAL	183	252	-40 TO +130	-
	AERO SHELL GREASE NO. 7*	AG7	MICROGEL	DIESTER	>260	288	-73 TO +149	MIL-G-23827B
	AERO SHELL GREASE NO.15A	AG5	FLUOROTELOMER	SILICONE	>260	280	-73 TO +260	-
ESSO	ANDOK B	AKB	SODIUM	MINERAL	260	285	-40 TO +120	MIL-G-18709A
	ANDOK C*	AKC	SODIUM	MINERAL	>260	205	-20 TO +120	-
	ANDOK 260	AK2	SODIUM	MINERAL	200	260	-30 TO +150	MIL-G-3545B
	BEACON 325*	B32	LITHIUM	DIESTER	193	280	-60 TO +120	MIL-G-3278A
KYODO YUSHI	MALTEMP PS NO.2*	PS2	LITHIUM	DIESTER, MINERAL	190	275	-55 TO +130	-
KYODO YUSHI	MALTEMP SRL*	NS7	LITHIUM	ESTER	191	245	-40 TO +150	-
KLUBER LUB.	STABURAGS NBU12	N12	BARIUM	MINERAL	220	270	-34 TO +150	-
	BARRIERTA L55/2	L55	FLUOROTELOMER	FLUORINATED	-	280	-35 TO +220	-
	BARRIERTA EL	IEL	FLUOROTELOMER	FLUORINATED	-	280	-50 TO +180	-
	BARRIERTA IMI/V	IMI	FLUOROTELOMER	FLUORINATED	-	280	-50 TO +220	-
	ISOFLEX NBU15	NB5	BARIUM	DIESTER, MINERAL	200	280	-40 TO +130	-
	ISOFLEX TOPAS NB52	NB2	BARIUM	SYNTHETIC HYDROCARBON	240	280	-60 TO +170	-
	ISOFLEX SUPER LDS18	SL8	LITHIUM	DIESTER	190	280	-60 TO +130	MIL-G-7118A
	ISOFLEX LDS18 SPECIAL A	L8A	LITHIUM	DIESTER	190	280	-60 TO _130	MIL-G-23827A
DOW CORNING	MOLYCOTE 33M	M3M	LITHIUM	SILICONE	210	260	-70 TO +180	-
	MOLYCOTE 44M	M4M	LITHIUM	SILICONE	204	260	-40 TO +200	-
	MOLYCOTE 55M	D5M	LITHIUM	SILICONE, ESTER	-	-	-	MIL-L-4343B
	MOLYCOTE BR2 PLUS	BR2	LITHIUM	MINERAL	-	280	-30 TO +150	-
	MOLYCOTE FS1292	F19	FLUOROTELOMER	FLUOROSILICONE	>232	310	-40 TO +200	-
	MOLYCOTE FS3451	F35	FLUOROTELOMER	FLUOROSILICONE	>260	285	-40 TO +230	-
MOBIL OIL CO.	MOBIL GREASE NO. 28	MG2	BENTONITE	SYNTHETIC HYDROCARBON	>260	280	-62 TO +204	MIL-G-81322C
CALTEX	CHEVRON SRI-2	SRL	UREA	MINERAL	-	-	-30 TO +175
DUPONT, E.I.	KRYTOX 240AC	K24	FLUOROTELOMER	FLUORINATED	-	282	-35 TO +288	MIL-G-27617A
NIHON OIL CO.	MULTINOCUREA	MNU	UREA	MINERAL	>260	290	-20 TO +175	-
SHINETSU SILICONE	SILICOLUBE G40M	G40	LITHIUM	SILICONE	210	260	-30 TO +200	-

* Typical Standard Lubricants - as shipped from factory. Custom lubricants - are typically a factory order.

TEMPERATURE CONVERSION: °F - (1.8 X °C) + 32

ABEC Tolerances/ISO Ratings

Precision ball bearings are manufactured to standards established by the Annular Bearing Engineers Committee (ABEC) of the American Bearing Manufacturers Association (ABMA). These standards have been accepted by the American National Standards Institute (ANSI) and conform essentially to the standards set by the International Standards Organization (ISO).

IMPORTANT NOTE - The ABEC and ISO bearing standards are primarily concerned with bearing tolerances. While tolerance is an important factor in the performance of a bearing, there are many other factors that also affect the suitability of a bearing to its application. ABEC and ISO standards do not cover: radial play, raceway curvature, surface finish, material, ball complement, number, size or precision level, retainer type, lubrication, torque, cleanliness at assembly, packaging and other factors that may be essential to the desired bearing performance.

ABEC/ISO TOLERANCE CHART
Inner Ring Tolerances - Inches (mm)
	TYPE	OD SIZE	ABEC1	ABEC 3	ABEC 5	ABEC 7
			ISO Normal	ISO P6	ISO P5	ISO P4
Mean Bore Tolerance	ALL	0 to .709	0 to -.0003	0 to -.0002	0 to -.0002	0 to -.0002
		(0 to 18)	(0 to -.008)	(0 to -.005)	(0 to -.005)	(O to -.005)
2 PT Out of Roundness	ALL	0 to .709	NS	NS	0.0001	0.0001
		(0 to 18)			(0.003)	(0.003)
Bore Taper	ALL	0 to .709	NS	NS	0.0001	0.0001
		(0 to 18)			(0.003)	(0.003)
Radial Runout	ALL	0 to .709	0.0003	0.0002	0.00015	0.0001
		(0 to 18)	(0.008)	(0.005)	(0.004)	(0.003)
Face Runout With Bore	ALL	0 to .709	NS	NS	0.0003	0.0001
		(0 to 18)			(0.008)	(0.003)
Face Runout	ALL	0 to .709	NS	NS	0.0003	0.0001
		(0 to 18)			(0.008)	(0.003)
Width Variation	ALL	0 to .709	NS	NS	0.0002	0.0001
		(0 to 18)			(0.005)	(0.003)
Ring Width Toerance	ALL	0 to 1.1811	0 to -.005	0 to -.005	0 to -.001	0 to -.001
		(0 to 30)	(0 to -.125)	(0 to -.125)	(0 to -.025)	(0 to -.025)

ABEC/ISO TOLERANCE CHART
Inner Ring Tolerances - Inches (mm)
	TYPE	OD SIZE	ABEC 1	ABEC 3	ABEC 5	ABEC 7
	TYPE	OD SIZE	ISO Normal	ISO P6	ISO P5	ISO P4
MEAN OD TOLERANCE	ALL	0 to .709	+0 to -.0003	+0 to -.0003	+0 to -.0002	+0 to -.0002
		(0 to 18)	(+0 to -.008)	(+0 to -.008)	(+0 to -.005)	(+0 to -.005)
		.709 to 1.1811	+0 to -.0004	+0 to -.0003	+0 to -.0002	+0 to -.0002
		(18 to 30)	(+0 to -.010)	(+0 to -.008)	(+0 to -.005)	(+0 to -.005)
MAX OD TOLERANCE LIMITS	OPEN	0 to .709	+.0001 to -.0004	+.0001 to -.0004	+0 to -.0002	+0 to -.0002
		(0 to 18)	(+.003 to -.010)	(+.003 to -.010)	(+0 to -.005)	(+0 to -.005)
		.709 to 1.1811	+.0001 to -.0005	+.0001 to -.0004	+0 to -.0002	+0 to -.0002
		(18 to 30)	(+.025 to -.010)	(+.025 to -.010)	(+0 to -.005)	(+0 to -.005)
		0 to .709	+.0002 to -.0005	+.0002 to -.0005	+.00004 to .00024	+.00004 to .00024
	SHIELDED	(0 to 18)	(+.005 to -.012)	(+.005 to -.012)	(+.001 to -.006)	(+.001 to -.006)
		.709 to 1.1811	+.0002 to -.0006	+.0002 to -.0005	+.00004 to .00024	+.00004 to .00024
		(18 to 30)	(+.005 to -.015)	(+.005 to -.012)	(+.001 to -.006)	(+.001 to -.006)
OD 2 PT OUT OF ROUNDNESS	OPEN	0 to .709	NS	NS	0.0001	0.0001
		(0 to 18)	-	-	(0.0025)	(0.0025)
		.709 to 1.1811	-	-	0.0001	0.0001
		(18 to 30)	NS	NS	(0.0025)	(0.0025)
	SHIELDED	0 to 1.1811	-	-	-	-
		(0 to 30)	NS	NS	0.0002	0.0002
		-	-	-	(0.005)	(0.005)
OD TAPER	OPEN	0 to 1.1811	NS	NS	0.0001	0.0001
		(0 to 30)	-	-	(0.0025)	(0.0025)
		0 to 1.1811	NS	NS	-	-
	SHIELDED	(0 to 30)	-	-	0.0002	0.0002
		-	-	-	(0.005)	(0.005)
RADIAL RUNOUT	ALL	0 to 1.1811	0.0006	0.0004	0.0002	0.00015
RADIAL RUNOUT	ALL	(0 to 30)	(0.015)	(0.01)	(0.005)	(0.004)
OD RUNOUT WITH FACE	ALL	0 to .709	NS	NS	0.0003	0.00015
OD RUNOUT WITH FACE	ALL	(0 to 18)	NS	NS	(0.008)	(0.004)
FACE RUNOUT	STRAIGHT	0 to 1.1811	-	-	0.0003	0.0002
		(0 to 30)	-	-	(0.008)	(0.005)
			NS	NS	-	-
	FLANGED	0 to -1.1811	-	-	0.0003	0.0003
		(0 to 30)	NS	NS	(0.008)	(0.008)
WIDTH VARIATION	ALL	0 to 1.1811	-	-	0 to -.002	0 to -.0001
WIDTH VARIATION	ALL	(0 to 30)	NS	NS	(0 to -.005)	(0 to -.003)
FLANGE WIDTH TOLERANCE		0 to 1.1811	0 to -.002	0 to -.002	0 to -.002	0 to -.002
FLANGE WIDTH TOLERANCE		(0 to 30)	(0 to -.050)	(0 to -.050)	(0 to -.050)	(0 to -.050)
FLANGE DIAMETER TOLERANCE		0 to 1.1811	+.005 to .002	+.005 to .002	0 to -.001	0 to -.001
FLANGE DIAMETER TOLERANCE		(0 to 30)	(+.125 to -.050)	(+.125 to -.050)	(0 to -.025)	(0 to -.025)

Internal Clearance

Internal clearance is the play between outer ring, inner ring and rolling element. Generally, the amount of up and down movement of the outer ring with respect to the fixed inner ring is called the radial internal clearance and its right and left movement the axial internal clearance.

Bearing internal clearance in operation is an important factor that has a significant influence on other factors such as noise, vibration, heat and fatigue life. Radial ball bearings are usually classified by their internal radial clearance.

When measuring the internal clearance, the bearing is subjected to a standard load in order to ensure full contact between all bearing components. Under such a load, the measured value is larger than the actual value stated for radial clearance; this is due to elastic deformation. The differance is compensated by the factors given in the tables below.

RADIAL INTERNAL CLEARANCE OF SMALL AND MINIATURE BEARINGS

CLEARANCE MARK		MC1	MC2	MC3	MC4	MC5	MC6
CLEARANCE	max	0	3	5	8	13	20
CLEARANCE	min	5	8	10	13	20	28
NOTE: 1) STANDARD CLEARANCE IS MC3. 2) FOR MEASURING CLEARANCE, OFFSET BY COMPENSATION FACTOR LISTED BELOW. 3) Unit um

CLEARANCE MARK	MC1	MC2	MC3	MC4	MC5	MC6
COMPENSATION FACTOR	1	1	1	1	2	2
NOTE: MEASURING LOAD IS AS FOLLOWS: MINIATURE BEARINGS 2.5N (0.25kgf), SMALL BEARINGS 4.4N (0.45kgf), Unit um

RADIAL INTERNAL CLEARANCE OF STANDARD RADIAL BALL BEARINGS

NOMINAL BORE DIAMETER d(mm)		CLEARANCE
NOMINAL BORE DIAMETER d(mm)		C2		C0		C3		C4		C5
OVER	INCL	MIN	MAX	MIN	MAX	MIN	MAX	MIN	MAX	MIN	MAX
10		0	7	2	13	8	23	14	29	20	37
10	18	0	9	3	18	11	25	18	33	25	45
18	24	0	10	5	20	13	28	20	36	28	48

24	30	1	11	5	20	13	28	23	41	30	53
30	40	1	11	6	20	15	33	28	46	40	64
40	50	1	11	6	23	18	36	30	51	45	73
NOTE: 1. FOR MEASURING CLEARANCE, OFFSET BY COMPENSATION FACTOR LISTED BELOW. , Unit um

BORE DIAMETER OF NOMINAL BEARING d(mm)		MEASURING LOAD	COMPENSATION FACTOR
OVER	INCL	N(kgf)	C2	C0	C3	C4	C5
10(INCLUDED)	18	24.5 (2.6)	3~4	4	4	4	4
18	50	49 (5)	4~5	5	6	6	6
NOTE: Unit um

RELATIONSHIP BETWEEN RADIAL INTERNAL AND AXIAL INTERNAL CLEARANCE

The axial internal clearance is established from the ball diameter, outer and inner ring raceway radius and the radial internal clearance. Usually it is about 10 times the value of the internal radial clearance. Selection of a small internal radial clearance or an extra large interference fit in order to reduce the internal axial clearance after mounting is not recommended.

SELECTION OF BEARING CLEARANCE

Theoretically, maximum bearing life is with very slight preload. However, even a slight increase in this theoretical preload can have a considerably detrimental effect on the bearing life. Positive clearance should therefore be selected. MC3 is usually used for miniature or small bearings, standard clearance for general bearings and the clearance for thin section bearings should never be greater than "standard".

Operating Condition	Clearance
Clearance fit for inner and outer ring. Low axial load. No axial load carrying requirement. Select bearing with reduced radial clearance. Lower vibration and noise. Low speeds.	MC1,MC2,C2
Lower frictional torque. Standard axial load. Average axial load carrying requirements. Slight interference fit for inner ring. Clearance fit for outer ring. Average/low speeds.	MC3,MC4,CN(C0)
Extremely low frictional torque. High axial load. High axial load carrying requirements. Heavy interfence fit to support high loads or shock loads. Large temperature gradient from inner ring to outer ring. High degree of shaft deflection.	MC5,MC6,C3,C4,C5

Maximum Permissable Bearing Speed

Each bearing type has its own limiting speed. The theoretical speed that bearings can run at safely, even if heat generation by internal friction occurs, is called the maximum permissible speed. The permissible speed is related to bearing type, type of cage, lubricant type, load and cooling conditions to which the bearing is subjected.

For contact rubber seals (2RS type), the permissible speeds are limited by the peripheral velocity of the seal lip. Normally, this is approximately 50 - 60% of that of non-contact rubber seals. If light contact rubber seals are required, this must be stipulated with the order. If high loads occur, the permissible speed values must be reduced and the following supplementary factors applied, except under standard operating conditions (Cr/P<12, Fa/Fr>0.2)

Compensation for maximum permissable speed dependent on load ratio.	Compensation for maximum permissable speed under combined axial and radial load

COMPENSATION FOR MAXIMUM PERMISSIBLE SPEED DEPENDENT ON LOAD RATIO
Cr/P	5	6	7	8	9	10	11	12
COMPENSATION FACTOR	0.72	0.79	0.85	0.90	0.93	0.96	0.98	1.00

COMPENSATION FOR MAX PERMISSIBLE SPEED UNDER COMBINED AXIAL & RADIAL LOAD
Fa/Fr	0.25	0.50	0.75	1.00	1.25	1.50	1.75	2.00
COMPENSATION FACTOR	1.00	0.95	0.93	0.91	0.89	0.88	0.87	0.86

If the bearing operates at over 70% of the permissible speed value, a lubricant for high speed should be selected. The values for the permissible speed are for applications with horizontal shafts and with appropriate lubrication. With vertical shafts, only 80% of the maximum speed speed value should be used. This is necessary due to the reduced cage guidance and reduced lubricant retention in this type of application.

Bearing Usage

NOTES ON SELECTING BEARINGS

The efficiency of thin type bearings can be greatly affected by the precision of the shaft and housing seats. The accuracy of the surrounding structure must be such that it will not adversely affect the operation of the bearing. If you have any questions, in particular regarding the 670 and 680 series, please contact us.
In applications with steel crown type cages (w type), where high acceleration, heavy loads, shock loads or vertical shafts occur, or where oil is the only lubricant, please contact us.
Selection of fitting clearance and grease type requires a careful consideration of rotating speed. load conditions and temperature in order to prevent premature bearing failure.
Full complement ball bearings are suitable for low speed and heavy radial load conditions. There is a danger of balls being pushed out of the bearing through the filling slot, even under light axial load. For this reason, full complement bearings are not suitable for supporting axial loads.

NOTES ON HANDLING BEARINGS

The actual assembly area should be kept free from dust as any contamination has a detrimental effect on the operation and life of roller bearings. If there is any doubt concerning the cleanliness of the bearing, it can be washed with a suitable agent and then relubricated.
When fitting bearings, the fitting forces must not be transmitted via the rolling elements. If it is necessary to heat the bearing to facilitate fitting, the temperature should not exceed +120° C.
After assembly, the bearing should be rotated to check its correct operation. If the bearing does not appear to be functioning correctly, it should be re-examined to establish the cause of the malfunction.
It is not advisable to mix oils and greases as this will affect the efficiency of the bearing.
Bearings must be stored in a clean environment with stable temperatures. Bearings should be handled with care to avoid the possibility of corrosion and rusting.
Lint-free cloth must be used to wipe shaft and housing seats to avoid the ingress of contaminants into the bearing.

BEARING USAGE

Problem		Cause	Remedy
Noise	High pitched metalic noise	Poor lubrication	Improve lubrication
		Clearance too small	Correct clearance
		Poor fitting	Investigate mounting method and seating
		Excesive load	Examine shaft and housing tolerances for closing effect
	Low pitched metallic noise	Brinelled raceway surface	Avoid shock loads
	Regular Noise	Rust and damage	Check and replace seals and relubricate
	Regular Noise	Flaking of raceway surface	Improve lubrication and check fitting, clearance and fixing method
	Iregular noise	Ingress of foreign matter	Check and replace seals and relubricate
		Excessive clearance	Correct clearance
		Damage and flaking of rolling element	Reduce loads and/or clearance
	Variable noise	Variable clearence due to temperature changes	check fits taking housing material and temperature into consideration
	Variable noise	Damage to raceway	Improve lubrication and check fitting, clearance and fixing method
Heavy vibration		Flaking of raceway and rolling element	Improve lubrication and check fitting, clearance and fixing method
		Ingress of foreign matter	Check and replace seals and relubricate
		Excessive clearance	Correct clearance
		Poor location	Ensure abutment face and fitting diamater are perpendicular
Excessive heat generation		Clearance too small	Correct clearance
		Poor location	Ensure abutment face and fitting diameter are perpendicular
		Excessive load	Examine shaft and housing tolerances for closing effect
		Poor lubrication	Improve lubrication
		Creep	Maintain recommended shaft and housing fits
Lubrication failure		Too much grease	Use correct lubricant quantity
Lubrication failure		Ingress of foreign matter	Check and replace seals and relubricate

Damage/Cause/Remedy

Problem	Damage	Cause	Remedy
High pitched metallic noise		Poor lubrication	Improve lubrication
		Clearance too small	Correct clearance
		Poor fitting	Investigate mounting seating & method
		Excessive load	Examine shaft and housing tolrances for closing effect
Low pitched metallic noise		Brinelled raceway surface	Avoid shock loads
Regular noise		Rust and damage	Check and replace seals and relubricate
Regular noise		Flaking of raceway surface	Improve lubrication and check fitting
Irregular noise		Ingress of foriegn matter	Check and replace seals and relubricate
		Excessive clearance	Correct clearance
		Damage and flaking of rolling element	Reduce loads and/or clearance
Variable noise		Variable clearance due to temperature changes	Check fits taking housing material and temperature into consideration
Variable noise		Damage to raceways	Improve lubrication and check fitting
Heavy Vibration		Flaking of raceway and rolling element	Improve lubrication and check fitting
		Ingress of foriegn matters	Check and replace seals and relubricate
		Excessive clearance	Correct clearance
		Poor location	Ensure abutment face and fitting diameter are perpendicular
Excessive Heat Generation		Clearance too small	Correct Clearance
		Poor Location	Ensure abutment face and fitting diameter are perpendicular
		Excessive load	Examine shaft and housing tolerance for closing effect
		Poor lubrication	Improve lubrication
		Creep	Maintain recommended shaft and housing fits
Lubrication Failure		Too much grease	Use correct lubricant quantity
Lubrication Failure		Ingress of foreign matter	Check and replace seals, relubricate
Flaking	Flaking on one side of entire raceway	Excessive axial load by poor fitting or linear expansion	Use clearance fit on non- locating bearing outer ring
	Flaking at rolling element pitch on raceways	Raceways brinelled during fitting	Careful fitting
	Flaking at rolling element pitch on raceways	Corrosion during down time	Apply corrosion protective
	Premature flaking of raceway and rolling element surfaces	Excessive load	Correct clearance
		Clearance too small	Correct clearance
		Poor lubrication	Use correct lubricant quantity
		Poor fitting	Check fitting
		Corrosion	Apply corrosion protective
	Flaking across the raceway	Poor fitting and eccentricity	Fitting and centering with care
		Shaft deflection	Use bearing with larger internal clearance
		Geometric inaccuracy of shaft and housing	Shaft and abutments to be square
	Flaking around araceway	Poor housing accuracy	Check geometric accuracy of housing bore
Indentations	Indentations on raceway at rolling element pitch	Shocks loads during fitting or poor handling	Handling with care
	Indentations on raceway at rolling element pitch	Excessive static load	Check static load
	Over-rolling	Ingress of foreign matter	Ensure cleanliness of components and integrityof seals
Pick-up	Discoloration of raceway and rolling element surface	Excessive load	Check fitting
	Discoloration of raceway and rolling element surface	Clearance too small	Correct clearance
	Softening of surfaces	Poor lubrication	Use correct lubricant quantity
	Softening of surfaces	Poor fitting	Check fitting method
Electrical erosion	Raceway eroded at regular intervals	Arching due to bearing conducting electricity	Earth or insulate the bearing
Fracture	Raceway surface fracture	Excessive shock loads	Correct loading
		High interference fit	Proper fitting
		Increase of flaking and softening	Ensure correct geometry of shaft and housing
		welding of inner ring to shaft	Ensure correct geometry of shaft and housing
		Corner fillet radii to large	Correct fillet radii
	Rolling element fracture	Excessive shocks loads	Correct loading
	Rolling element fracture	Excessive internal clearance	Check fiting and clearance
	Cage fracture	Tilting moments	Fit with care
		High speed impulse and high acceleration	Ensure uniform rotation
		Incorrect lubrication	Check lubricant and lubrication method
		Ingress of foreign matter in bearing	Improve sealing
Skidding	Scoring of raceway and rolling element surfaces	Hard grease	Use soft grease
Skidding	Scoring of raceway and rolling element surfaces	High start up acceleration	Controlled acceleration
Abrasion	Extreme abrasion of raceway, rolling element and cage	Ingress of foreign matter	Improve Sealing
		Corrosion	Improve Sealing
		Poor lubrication	Improve lubrication
	Creep	Loose fit	Correct tolerances and fitting
	Creep	Incorrectly fixed	Correct fixing
	Fretting corrosion	Small movement between surfaces	Increase interference fit
	False brinelling	Vibration in non-rotating bearing	Insulate bearing from vibration
	False brinelling	Small oscillations in applications	Use oil as lubricant, Apply preload
Corrosion	Rust inside bearing	Poor storage	Careful storage and handling
	Rust inside bearing	Condensation	Careful storage and handling
	Rust on fitting surface	Fretting	Increase interference fit
	Rust on fitting surface	Fluctuating load	Use oil as lubricant
	Corrosion	Ingress of acid, alkali or gas	Check sealing
	Corrosion	Chemical reaction with lubricant	Use correct lubricant