Everything You Should Know About Angular Contact Bearings

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Everything You Should Know About Angular Contact Bearings

Angular contact bearings are designed so that the bearing forms a contact angle between the races and the balls when in use, with inner and outer raceways slightly offset from each other, which causes the balls to be mounted at an angle. Due to this offset, they are suitable for carrying radial and axial loads. The main benefit of bearings arranged at an angle is that the axial load capacity increases as the angle of the bearing balls increases. This angular arrangement also increases the service life of the bearing. Angular contact bearings provide higher operating speeds and better durability. They can be used where high precision, high speed, radial and axial loads are present; for example in gearboxes, pumps and machine tool applications.

Angular contact bearings have inner and outer raceways and a set of balls rolling between the raceways, which must be loaded with thrust during assembly. This load (or preload) creates a contact line (or contact angle) between the inner ring, balls and outer ring. Preload can be built into the bearing or it can be created when the bearing is inserted into the assembly. Contact angles vary from 15° to 40° and are measured relative to a line perpendicular to the bearing axis. Angular contact ball bearings are capable of operating at much higher speeds than deep groove ball bearings.

Angular contact ball bearing components and terminology

Below is a list of technical terms to know related to angular contact ball bearings:

Inner Ring: The inner ring is the inner ring of the bearing. This is the part that fits directly on the shaft.
Outer Ring: The outer ring forms the exterior of the bearing. Since it doesn’t usually move like the inner ring, its main role is to house and protect the internal components.
Raceways: The inner and outer raceways are the outer portion of the inner ring and the inner portion of the outer ring, usually consisting of a grooved path to facilitate the movement of the balls.
Balls: The balls rotate along the raceways to reduce friction in motion in the bearing.
Cages: Cages are separators within the raceways that help keep the balls evenly distributed.
Full Complement: Full Complement bearings have no cage and the space is completely occupied by the bearing balls.
Radial Load: Radial load measures the maximum vertical force a bearing can withstand. This force results in rotational motion.
Axial Load: Axial load measures the maximum force applied in line with the shaft. It causes turning.
Bearing Preload: Preload is a non-applied axial load applied to a bearing to establish optimum load capacity, reduce slip and improve running accuracy.
Nominal contact angle: The contact angle is the inclination of the intersection of the ball and the raceway along the radial plane. Depending on axial load requirements, angular contact ball bearings have a slight inclination of 15-40 degrees. The contact angle can be adjusted to accommodate any axial load.
Lubrication: Bearings are made of rollers and bearing rings. During operation, the rollers slide within the rings. This makes it a source of friction and a common point of failure. By applying bearing lubricant between these surfaces, the heat generated by friction is reduced, ensuring longer life for the bearing. Read in our article on bearing lubrication.
Sealed Bearings: Bearings can be fully open, partially enclosed or fully enclosed. Fully open bearings offer less protection from the elements, but do allow for easy lubrication and maintenance. Partially enclosed bearings have a retainer that protects the bearing balls from damage. Fully enclosed bearings are completely protected from the elements, however, they are not easily maintained and require replacement rather than repair at the end of their useful life.

Ratings

Bearing manufacturers typically assign bearings an ABEC class. The ABEC (Annular Bearing Engineers Council) ratings classify bearings into different precision and tolerance ranges. The higher the ABEC number, the tighter the bearing tolerances.

Seal Type and Material

Angular contact bearings can have many different types of seals or shields. Seals and guards prevent contamination and act as lubricant retainers. Seals provide better protection and lubricant sealing than guards, but have lower maximum speed capabilities. Types include:

Single seal
Double seal
Single shield
Double shield

Angular contact bearings are available in exotic materials including stainless steel, plastic and ceramic hybrids. They may also be plated; common plating materials are cadmium and chromium.

Angular contact bearing types

Single Row Angular Contact Ball Bearings

Single row angular contact ball bearings are designed to accommodate higher load capacities. One flange is higher near the contact angle and lower at the other end. The size of the contact angle affects the speed and load capacity of the bearing. For example, a contact angle of 15 degrees provides higher speed and radial load capacity, but lower axial load direction. The 40 degree angle has higher axial load capacity, but only for lower speeds and loads. The advantages of single row angular contact ball bearings include:

Part Number	Bore Dia	Outer Dia	Width	Ring Material	Ball Material	Cage Material	Dynamic Radial Load	Static Radial Load
307238	400 mm	600 mm	90 mm	52100 Chrome Steel	52100 Chrome Steel	Polyamide	605 kN	1180 kN
466953	380 mm	520 mm	65 mm	52100 Chrome Steel	52100 Chrome Steel	Polyamide	345 kN	610 kN
468431	410 mm	560 mm	70 mm	52100 Chrome Steel	52100 Chrome Steel	Polyamide	423 kN	830 kN
70/1000 AMB	1000 mm	1420 mm	185 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	1630 kN	5400 kN
70/1060 AMB	1060 mm	1500 mm	195 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	1680 kN	5700 kN
70/1120 AMB	1120 mm	1580 mm	200 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	1780 kN	6400 kN
70/1180 AMB	1180 mm	1660 mm	212 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	1740 kN	6200 kN
70/1250 AMB	1250 mm	1750 mm	218 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	1990 kN	7650 kN
70/500 AM	500 mm	720 mm	100 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	715 kN	1600 kN
70/500 BM	500 mm	720 mm	100 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	637 kN	1400 kN
70/530 AM	530 mm	780 mm	112 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	832 kN	1900 kN
70/530 BM	530 mm	780 mm	112 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	741 kN	1700 kN
70/600 AGMB	600 mm	870 mm	118 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	884 kN	2160 kN
70/630 AMB	630 mm	920 mm	128 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	956 kN	2450 kN
70/710 AMB	710 mm	1030 mm	140 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	1190 kN	3250 kN
70/750 AMB	750 mm	1090 mm	150 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	1300 kN	3650 kN
70/900 AMB	900 mm	1280 mm	170 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	1560 kN	4900 kN
70/950 AMB	950 mm	1360 mm	180 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	1630 kN	5200 kN
7024 BGM	120 mm	180 mm	28 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	87.1 kN	93 kN
7028 BGM	140 mm	210 mm	33 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	114 kN	129 kN
7030 BGM	150 mm	225 mm	35 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	133 kN	146 kN
7034 BGM	170 mm	260 mm	42 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	172 kN	204 kN
7036 BGM	180 mm	280 mm	46 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	195 kN	240 kN
7038 BGM	190 mm	290 mm	46 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	199 kN	255 kN
7040 BGM	200 mm	310 mm	51 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	225 kN	290 kN
7044 BGM	220 mm	340 mm	56 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	255 kN	355 kN
7048 BGM	240 mm	360 mm	56 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	260 kN	375 kN
7052 BGM	260 mm	400 mm	65 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	332 kN	510 kN
7056 BGM	280 mm	420 mm	65 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	338 kN	540 kN
7060 AGM	300 mm	460 mm	74 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	423 kN	695 kN
7060 BGM	300 mm	460 mm	74 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	377 kN	630 kN
7064 BGM	320 mm	480 mm	74 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	390 kN	670 kN
7068 BGM	340 mm	520 mm	82 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	449 kN	815 kN
7072 AGM	360 mm	540 mm	82 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	520 kN	950 kN
7072 AM	360 mm	540 mm	82 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	520 kN	950 kN
7072 BGM	360 mm	540 mm	82 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	462 kN	850 kN
7076 AM	380 mm	560 mm	82 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	507 kN	950 kN
7076 BGM	380 mm	560 mm	82 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	468 kN	850 kN
7076 BM	380 mm	560 mm	82 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	468 kN	850 kN
708/1250 AMB	1250 mm	1500 mm	80 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	806 kN	2700 kN
708/500 AMB	500 mm	620 mm	37 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	276 kN	620 kN
708/600 AGMB	600 mm	730 mm	42 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	338 kN	735 kN
708/600 AMB	600 mm	730 mm	42 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	338 kN	735 kN
7080 AM	400 mm	600 mm	90 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	605 kN	1180 kN
7080 BM	400 mm	600 mm	90 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	527 kN	1020 kN
7084 AM	420 mm	620 mm	90 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	605 kN	1180 kN
7084 BGM	420 mm	620 mm	90 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	540 kN	1060 kN
70876 AMB	380 mm	480 mm	31 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	190 kN	355 kN
7088 AM	440 mm	650 mm	94 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	650 kN	1320 kN
7088 BM	440 mm	650 mm	94 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	572 kN	1180 kN
70892 AM	460 mm	580 mm	37 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	265 kN	560 kN
7092 AM	460 mm	680 mm	100 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	689 kN	1460 kN
7092 BM	460 mm	680 mm	100 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	618 kN	1290 kN
7096 AM	480 mm	700 mm	100 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	702 kN	1530 kN
7096 BM	480 mm	700 mm	100 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	624 kN	1340 kN
718/1000 AMB	1000 mm	1220 mm	100 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	923 kN	2750 kN
718/1120 AMB	1120 mm	1360 mm	106 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	1060 kN	3750 kN
718/1250 AMB	1250 mm	1500 mm	112 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	1140 kN	3900 kN
718/500 AGMB	500 mm	620 mm	56 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	390 kN	850 kN
718/500 AMB	500 mm	620 mm	56 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	390 kN	850 kN
718/530 AMB	530 mm	650 mm	56 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	390 kN	900 kN
718/560 AMB	560 mm	680 mm	56 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	397 kN	930 kN
718/600 AMB	600 mm	730 mm	60 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	449 kN	1100 kN
718/670 ACMB	670 mm	820 mm	69 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	553 kN	1290 kN
718/670 AMB	670 mm	820 mm	69 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	527 kN	1250 kN
718/710 AMB	710 mm	870 mm	74 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	572 kN	1560 kN
718/750 ACMB	750 mm	920 mm	78 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	650 kN	1800 kN
718/750 AGMB	750 mm	920 mm	78 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	618 kN	1730 kN
718/850 AMB	850 mm	1030 mm	82 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	689 kN	1860 kN
71872 ACMB	360 mm	440 mm	38 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	234 kN	425 kN
71876 ACGAMB	380 mm	480 mm	46 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	291 kN	500 kN
71892 AGMB	460 mm	580 mm	56 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	371 kN	765 kN
719/500 AGMB	500 mm	670 mm	78 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	553 kN	1220 kN
719/530 ACM	530 mm	710 mm	82 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	618 kN	1340 kN
719/560 AMB	560 mm	750 mm	85 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	592 kN	1290 kN
719/600 ACM	600 mm	800 mm	90 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	715 kN	1730 kN
719/710 ACMB	710 mm	950 mm	106 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	852 kN	2200 kN
71964 AC	320 mm	440 mm	56 mm	52100 Chrome Steel	52100 Chrome Steel	Polyamide	351 kN	585 kN
71968 ACMB	340 mm	460 mm	56 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	338 kN	585 kN
71972 ACMB	360 mm	480 mm	56 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	351 kN	630 kN
71972 AMB	360 mm	480 mm	56 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	338 kN	610 kN
71972 BM	360 mm	480 mm	56 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	302 kN	550 kN
71976 ACGAMB	380 mm	520 mm	65 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	410 kN	735 kN
71980 AM	400 mm	540 mm	65 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	403 kN	735 kN
71984 AGAM	420 mm	560 mm	65 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	410 kN	765 kN
71984 BM	420 mm	560 mm	65 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	364 kN	670 kN
71988 ACMB	440 mm	600 mm	74 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	507 kN	1040 kN
71992 ACM	460 mm	620 mm	74 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	507 kN	1040 kN
7200 BECBP	10 mm	30 mm	9 mm	52100 Chrome Steel	52100 Chrome Steel	Polyamide	7.02 kN	3.35 kN
7200 BEP	10 mm	30 mm	9 mm	52100 Chrome Steel	52100 Chrome Steel	Polyamide	7.02 kN	3.35 kN
7201 BECBP	12 mm	32 mm	10 mm	52100 Chrome Steel	52100 Chrome Steel	Polyamide	7.61 kN	3.8 kN
7201 BEGAP	12 mm	32 mm	10 mm	52100 Chrome Steel	52100 Chrome Steel	Polyamide	7.61 kN	3.8 kN
7201 BEP	12 mm	32 mm	10 mm	52100 Chrome Steel	52100 Chrome Steel	Polyamide	7.61 kN	3.8 kN
7202 ACCBM	15 mm	35 mm	11 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	10.2 kN	5.2 kN
7202 BE-2RZP	15 mm	35 mm	11 mm	52100 Chrome Steel	52100 Chrome Steel	Polyamide	8.32 kN	4.4 kN
7202 BECBP	15 mm	35 mm	11 mm	52100 Chrome Steel	52100 Chrome Steel	Polyamide	8.8 kN	4.65 kN
7202 BEGAP	15 mm	35 mm	11 mm	52100 Chrome Steel	52100 Chrome Steel	Polyamide	8.8 kN	4.65 kN
7202 BEGBP	15 mm	35 mm	11 mm	52100 Chrome Steel	52100 Chrome Steel	Polyamide	8.8 kN	4.65 kN
7202 BEP	15 mm	35 mm	11 mm	52100 Chrome Steel	52100 Chrome Steel	Polyamide	8.32 kN	4.4 kN
7203 ACCBM	17 mm	40 mm	12 mm	52100 Chrome Steel	52100 Chrome Steel	Brass Cage	12.5 kN	6.7 kN

Capacity for high loads due to the larger number of balls in the bearing.
An excellent running capacity that allows for rapid acceleration and deceleration of the bearings.

Figure 2: Single row angular contact ball bearing

Single row angular contact ball bearing mounting positions

The single-row bearing must be preloaded in the direction of the contact angle as it can only handle axial loads in that direction. Two single-row bearings can be fitted in back to back, face to face, or tandem arrangements:

Back-to-back: Back-to-back mounted angular ball bearings can accommodate both radial and axial loads in any direction. The distance between the bearing center and loading point (D) is larger than other mounting methods, it can therefore handle large momentary and alternating radial load forces. This mounting method is the most common (Figure 3-A).
Face-to-face: Through this mounting sequence the bearing can handle radial and axial loads in either direction. However, because the distance between the bearing center and loading point (D) is smaller through this mount, momentary and alternating radial force capacity is lower (Figure 3-B).
Tandem: A tandem mount can accommodate single direction axial loads as well as radial loads. Because the loads on the axis are received by both bearings it can handle heavy axial loads (Figure 3-C).

Figure 3: Single row angular contact bearing mounting methods: back-to-back (A), face-to-face (B), and tandem (C). The distance between the bearing center and loading point (D).

Double-row angular contact ball bearings

Part Number	Seal Type	Bore Dia	Outer Dia	Width	Ring Material	Dynamic Radial Load	Static Radial Load
305256 D	Open	120 mm	190 mm	66 mm	52100 Chrome Steel	182 kN	232 kN
305262 D	Open	180 mm	259.5 mm	66 mm	52100 Chrome Steel	225 kN	310 kN
305263 D	Open	200 mm	289.5 mm	76 mm	52100 Chrome Steel	302 kN	475 kN
305263 DA	Open	200 mm	289.5 mm	76 mm	52100 Chrome Steel	302 kN	475 kN
305264 D	Open	230 mm	329.5 mm	80 mm	52100 Chrome Steel	351 kN	600 kN
305269 D	Open	280 mm	389.5 mm	92 mm	52100 Chrome Steel	403 kN	750 kN
305270 D	Open	260 mm	369.5 mm	92 mm	52100 Chrome Steel	397 kN	710 kN
305272 D	Open	220 mm	309.5 mm	76 mm	52100 Chrome Steel	312 kN	520 kN
305272 DA	Open	220 mm	309.5 mm	76 mm	52100 Chrome Steel	312 kN	520 kN
305272 DB	Open	220 mm	309.5 mm	76 mm	52100 Chrome Steel	312 kN	520 kN
305283 D	Open	150 mm	230 mm	70 mm	52100 Chrome Steel	203 kN	285 kN
305283 DA	Open	150 mm	230 mm	70 mm	52100 Chrome Steel	203 kN	285 kN
305286 D	Open	150 mm	225 mm	73 mm	52100 Chrome Steel	182 kN	265 kN
305288 DA	Open	180 mm	250 mm	70 mm	52100 Chrome Steel	190 kN	285 kN
305338 D	Open	190 mm	269.5 mm	66 mm	52100 Chrome Steel	270 kN	415 kN
305428 D	Open	200 mm	279.5 mm	76 mm	52100 Chrome Steel	242 kN	380 kN
305608	Open	160 mm	215 mm	56 mm	52100 Chrome Steel	135 kN	220 kN
305608 B	Open	160 mm	215 mm	56 mm	52100 Chrome Steel	135 kN	220 kN
3200 A-2RS1TN9/MT33	Sealed	10 mm	30 mm	14 mm	52100 Chrome Steel	7.61 kN	4.3 kN
3200 A-2ZTN9/MT33	Shielded	10 mm	30 mm	14 mm	52100 Chrome Steel	7.61 kN	4.3 kN
3200 ATN9	Open	10 mm	30 mm	14 mm	52100 Chrome Steel	7.61 kN	4.3 kN
3201 A-2RS1TN9/MT33	Sealed	12 mm	32 mm	15.9 mm	52100 Chrome Steel	10.1 kN	5.6 kN
3201 A-2ZTN9/MT33	Shielded	12 mm	32 mm	15.9 mm	52100 Chrome Steel	10.1 kN	5.6 kN
3201 ATN9	Open	12 mm	32 mm	15.9 mm	52100 Chrome Steel	10.1 kN	5.6 kN
3202 A-2RS1TN9/MT33	Sealed	15 mm	35 mm	15.9 mm	52100 Chrome Steel	11.2 kN	6.8 kN
3202 A-2ZTN9/MT33	Shielded	15 mm	35 mm	15.9 mm	52100 Chrome Steel	11.2 kN	6.8 kN
3202 ATN9	Open	15 mm	35 mm	15.9 mm	52100 Chrome Steel	11.2 kN	6.8 kN
3203 A-2RS1TN9/MT33	Sealed	17 mm	40 mm	17.5 mm	52100 Chrome Steel	14.3 kN	8.8 kN
3203 A-2ZTN9/MT33	Shielded	17 mm	40 mm	17.5 mm	52100 Chrome Steel	14.3 kN	8.8 kN
3203 ATN9	Open	17 mm	40 mm	17.5 mm	52100 Chrome Steel	14.3 kN	8.8 kN
3204 A	Open	20 mm	47 mm	20.6 mm	52100 Chrome Steel	20.4 kN	12.9 kN
3204 A-2RS1	Sealed	20 mm	47 mm	20.6 mm	52100 Chrome Steel	20.4 kN	12.9 kN
3204 A-2RS1TN9/MT33	Sealed	20 mm	47 mm	20.6 mm	52100 Chrome Steel	20.4 kN	12.9 kN
3204 A-2Z	Shielded	20 mm	47 mm	20.6 mm	52100 Chrome Steel	20.4 kN	12.9 kN
3204 A-2ZTN9/MT33	Shielded	20 mm	47 mm	20.6 mm	52100 Chrome Steel	20.4 kN	12.9 kN
3204 ATN9	Open	20 mm	47 mm	20.6 mm	52100 Chrome Steel	20.4 kN	12.9 kN
3205 A	Open	25 mm	52 mm	20.6 mm	52100 Chrome Steel	22 kN	15.3 kN
3205 A-2RS1	Sealed	25 mm	52 mm	20.6 mm	52100 Chrome Steel	22 kN	15.3 kN
3205 A-2RS1TN9/MT33	Sealed	25 mm	52 mm	20.6 mm	52100 Chrome Steel	22 kN	15.3 kN
3205 A-2Z	Shielded	25 mm	52 mm	20.6 mm	52100 Chrome Steel	22 kN	15.3 kN
3205 A-2ZTN9/MT33	Shielded	25 mm	52 mm	20.6 mm	52100 Chrome Steel	22 kN	15.3 kN
3206 A	Open	30 mm	62 mm	23.8 mm	52100 Chrome Steel	30.5 kN	22 kN
3206 A-2RS1	Sealed	30 mm	62 mm	23.8 mm	52100 Chrome Steel	30.5 kN	22 kN
3206 A-2RS1TN9/MT33	Sealed	30 mm	62 mm	23.8 mm	52100 Chrome Steel	30.5 kN	22 kN
3206 A-2Z	Shielded	30 mm	62 mm	23.8 mm	52100 Chrome Steel	30.5 kN	22 kN
3206 A-2ZTN9/MT33	Shielded	30 mm	62 mm	23.8 mm	52100 Chrome Steel	30.5 kN	22 kN
3206 ATN9	Open	30 mm	62 mm	23.8 mm	52100 Chrome Steel	30.5 kN	22 kN
3207 A	Open	35 mm	72 mm	27 mm	52100 Chrome Steel	40.5 kN	30 kN
3207 A-2RS1	Sealed	35 mm	72 mm	27 mm	52100 Chrome Steel	40.5 kN	30 kN
3207 A-2RS1TN9/MT33	Sealed	35 mm	72 mm	27 mm	52100 Chrome Steel	40.5 kN	30 kN
3207 A-2Z	Shielded	35 mm	72 mm	27 mm	52100 Chrome Steel	40.5 kN	30 kN
3207 A-2ZTN9/MT33	Shielded	35 mm	72 mm	27 mm	52100 Chrome Steel	40.5 kN	30 kN
3207 ATN9	Open	35 mm	72 mm	27 mm	52100 Chrome Steel	40.5 kN	30 kN
3208 A	Open	40 mm	80 mm	30.2 mm	52100 Chrome Steel	48 kN	36.5 kN
3208 A-2RS1	Sealed	40 mm	80 mm	30.2 mm	52100 Chrome Steel	48 kN	36.5 kN
3208 A-2RS1TN9/MT33	Sealed	40 mm	80 mm	30.2 mm	52100 Chrome Steel	48 kN	36.5 kN
3208 A-2Z	Shielded	40 mm	80 mm	30.2 mm	52100 Chrome Steel	48 kN	36.5 kN
3208 A-2ZTN9/MT33	Shielded	40 mm	80 mm	30.2 mm	52100 Chrome Steel	48 kN	36.5 kN
3208 ATN9	Open	40 mm	80 mm	30.2 mm	52100 Chrome Steel	48 kN	36.5 kN
3209 A	Open	45 mm	85 mm	30.2 mm	52100 Chrome Steel	52 kN	41.5 kN
3209 A-2RS1	Sealed	45 mm	85 mm	30.2 mm	52100 Chrome Steel	52 kN	41.5 kN
3209 A-2RS1TN9/MT33	Sealed	45 mm	85 mm	30.2 mm	52100 Chrome Steel	52 kN	41.5 kN
3209 A-2Z	Shielded	45 mm	85 mm	30.2 mm	52100 Chrome Steel	52 kN	41.5 kN
3209 A-2ZTN9/MT33	Shielded	45 mm	85 mm	30.2 mm	52100 Chrome Steel	52 kN	41.5 kN
3209 ATN9	Open	45 mm	85 mm	30.2 mm	52100 Chrome Steel	52 kN	41.5 kN
3210 A	Open	50 mm	90 mm	30.2 mm	52100 Chrome Steel	51 kN	42.5 kN
3210 A-2RS1	Sealed	50 mm	90 mm	30.2 mm	52100 Chrome Steel	51 kN	42.5 kN
3210 A-2RS1TN9/MT33	Sealed	50 mm	90 mm	30.2 mm	52100 Chrome Steel	51 kN	42.5 kN
3210 A-2Z	Shielded	50 mm	90 mm	30.2 mm	52100 Chrome Steel	51 kN	42.5 kN
3210 A-2ZTN9/MT33	Shielded	50 mm	90 mm	30.2 mm	52100 Chrome Steel	51 kN	42.5 kN
3210 ATN9	Open	50 mm	90 mm	30.2 mm	52100 Chrome Steel	51 kN	42.5 kN
3211 A	Open	55 mm	100 mm	33.3 mm	52100 Chrome Steel	61 kN	52 kN
3211 A-2RS1	Sealed	55 mm	100 mm	33.3 mm	52100 Chrome Steel	61 kN	52 kN
3211 A-2Z	Shielded	55 mm	100 mm	33.3 mm	52100 Chrome Steel	61 kN	52 kN
3211 ATN9	Open	55 mm	100 mm	33.3 mm	52100 Chrome Steel	61 kN	52 kN
3212 A	Open	60 mm	110 mm	36.5 mm	52100 Chrome Steel	75 kN	64 kN
3212 A-2RS1	Sealed	60 mm	110 mm	36.5 mm	52100 Chrome Steel	75 kN	64 kN
3212 A-2RS1TN9/MT33	Sealed	60 mm	110 mm	36.5 mm	52100 Chrome Steel	75 kN	64 kN
3212 A-2Z	Shielded	60 mm	110 mm	36.5 mm	52100 Chrome Steel	75 kN	64 kN
3212 ATN9	Open	60 mm	110 mm	36.5 mm	52100 Chrome Steel	75 kN	64 kN
3213 A	Open	65 mm	120 mm	38.1 mm	52100 Chrome Steel	80.6 kN	73.5 kN
3213 A-2RS1	Sealed	65 mm	120 mm	38.1 mm	52100 Chrome Steel	80.6 kN	73.5 kN
3213 A-2Z	Shielded	65 mm	120 mm	38.1 mm	52100 Chrome Steel	80.6 kN	73.5 kN
3214 A	Open	70 mm	125 mm	39.7 mm	52100 Chrome Steel	88.4 kN	80 kN
3214 A-2Z	Shielded	70 mm	125 mm	39.7 mm	52100 Chrome Steel	88.4 kN	80 kN
3215 A	Open	75 mm	130 mm	41.3 mm	52100 Chrome Steel	95.6 kN	88 kN
3215 A-2Z	Shielded	75 mm	130 mm	41.3 mm	52100 Chrome Steel	95.6 kN	88 kN
3216 A	Open	80 mm	140 mm	44.4 mm	52100 Chrome Steel	106 kN	95 kN
3217 A	Open	85 mm	150 mm	49.2 mm	52100 Chrome Steel	124 kN	110 kN
3218 A	Open	90 mm	160 mm	52.4 mm	52100 Chrome Steel	130 kN	120 kN
3219 A	Open	95 mm	170 mm	55.6 mm	52100 Chrome Steel	159 kN	146 kN
3220 A	Open	100 mm	180 mm	60.3 mm	52100 Chrome Steel	178 kN	166 kN
3222 A	Open	110 mm	200 mm	69.8 mm	52100 Chrome Steel	212 kN	212 kN
3302 A-2RS1	Sealed	15 mm	42 mm	19 mm	52100 Chrome Steel	15.1 kN	9.3 kN
3302 A-2RS1TN9/MT33	Sealed	15 mm	42 mm	19 mm	52100 Chrome Steel	15.1 kN	9.3 kN
3302 A-2Z	Shielded	15 mm	42 mm	19 mm	52100 Chrome Steel	15.1 kN	9.3 kN
3302 A-2ZTN9/MT33	Shielded	15 mm	42 mm	19 mm	52100 Chrome Steel	15.1 kN	9.3 kN
3302 ATN9	Open	15 mm	42 mm	19 mm	52100 Chrome Steel	15.1 kN	9.3 kN
3303 A-2RS1	Sealed	17 mm	47 mm	22.2 mm	52100 Chrome Steel	21.6 kN	12.7 kN
3303 A-2RS1TN9/MT33	Sealed	17 mm	47 mm	22.2 mm	52100 Chrome Steel	21.6 kN	12.7 kN

The double row angular contact ball bearing is similar to two single-row bearings arranged back-to-back. In addition to radial and axial loads, they are also capable of absorbing tilting moments. The advantages of double-row contact bearings include:

While typically expensive than single-row bearings, double-row bearings can be economical in the long run.
Take up less axial space which is useful when two single-row bearings would take up too much space
Accommodates radial and axial loads, as well as tilting moments

Figure 4: Double row angular contact ball bearing

Four-point contact ball bearings

The 4-point contact ball bearing is similar to a single-row angular ball bearing It consists of an outer race that is flanked on both sides, an inner race is also flanked on both sides with a split in the middle, and steel balls circled by a cage. The flanks, or flanges, are symmetrical unlike single and double angular contact bearings.

There are several advantages of four-point contact ball bearings:

The split inner raceways of four-point contact ball bearings allow for easy mounting and dismounting of the bearing for maintenance.
The recess in the inner raceway allows for better oil flow.
These bearings work in a similar fashion to double-row or two single-row mounted angular contact bearings but take up less space.
Allows for loads in both axial and radial directions.
High load-carrying capacity due to a relatively higher number of balls than other ball bearings.

Figure 5: Four point contact ball bearing

Selection Criteria

When selecting an angular contact bearing, the main considerations revolve around speed, load type, load magnitude, seal type, tolerances and bearing size:

Speed: The speed an angular ball bearing can operate on depends on various factors such as ball angle, lubrication type, bearing size. When choosing a bearing compare your operational speed needs, desired lubrication type, and required load capacity to determine the speed capacity of your bearing. Keeping in mind that the operational speed of grease lubrication is lower than oil lubrication, info on this can be found in our Tribology series of articles and our bearing lubrication article. A smaller ball angle will also be able to achieve higher speeds, yet sacrifice load-bearing capacity.

Loads: Angular ball bearings are capable of handling both radial and axial loads. The choice between single, double, or four-point angular ball bearings, depends on the type, direction, and amount of loads present in the application. The end-user should also include the static radial load capacity, the maximum static load a bearing can withstand without excessive deformation; and the dynamic radial load, a constant load a bearing can endure for a preset amount of revolutions, typically one million revolutions.

Lubrication and seal type: Choose between relubricate, typically an open or shielded seal design for oil and grease; pre-lubricated, typically a shielded or closed seal design for oil and grease; or solid lubrication, polymer-based solid lubrication typically in a closed design.

Dimensions: Choose bearing dimension based on the type of load, amount of load, size of shaft, or the sie of the housing.

AUB manufactures angular contact bearings

AUB is a professional angular contact bearing manufacturer in China. Today we are a globally successful company in the development and manufacture of rolling bearings and supply than 600 customers in over 35 countries. Whether standard or special bearings, whether for original equipment or replacement requirements – we offer you the best possible.

Accommodating axial and radial forces
Suitable for very high speeds
Assembled in pairs

Single row angular contact ball bearings have angular raceways for the inner and outer rings and the resulting force-transmitting contact angles. Therefore, an axial load will always cause a radial load and vice versa, which is why angular contact ball bearings are always used in combination with a second bearing. When paired, in addition to radial forces, they can also absorb axial forces and combined forces, especially for high speeds. Single row angular contact ball bearings cannot be disassembled.

Dimensions and Tolerances

AUB offers angular contact ball bearings in standard tolerances (PN) according to DIN 620-2 (Roller bearing tolerances) and ISO 492 (Radial bearings – Dimensional and geometrical tolerances). All other deviations or special tolerances must be specified on the order.

Standard

The general dimensions of single row angular contact ball bearings are standardised in DIN 628-1 (Angular contact radial ball bearings), DIN 616 (Rolling bearings – Dimensions), and ISO 15 (Radial bearings – Boundary dimensions, general plan).

Bearing Design

Angular contact ball bearings are self-latching radial bearings that cannot be disassembled. In addition to high radial forces, they can absorb single-sided axial forces as well as, in combination with a second mirror-image arranged angular contact ball bearing, two-sided axial forces. For combined bearing sets there is a distinction between O-, X- or tandem arrangement based on pressure line contact. Bearings in X-arrangement are less suitable for the absorption of moment loads while the O-arrangement is very rigid and only allows small overturning clearance. For tandem arrangements, the pressure lines of two bearings run in one direction which results in only single-sided absorption of axial forces. In the process, the axial load is absorbed by both bearings in the pair and the axial load capacity is increased.

Different positioning of angular contact ball bearings in X-, O-, and tandem arrangement

Single row angular contact ball bearing in its default design; α – contact angle

The axial load capacity of an angular contact ball bearing is increased with a larger contact angle. Angular contact ball bearings of the series 72B, 73B and 74B are by default supplied with a contact angle of 40°, the series 708, 709, 718, 719 and 70 (without suffix B) with 30°.

Bearing Clearance and Preload

Angular contact ball bearings are divided into clearance classes and preload classes. These are not standardised. AUB bearing clearance classes and preload classes are defined by suffixes.

Cage

By default, angular contact ball bearings by AUB are equipped with a roller riding solid brass window-type cage (suffix: MP). Other cage designs are available on request or chosen for specific applications and labelled accordingly on the bearing.

Special Suffixes

B Modified internal design, contact angle 40°
D Modified internal design, contact angle 20°
E Modified internal design, contact angle 25°

Compensation of Angular Misalignments

Single row angular contact ball bearings are of limited suitability for compensation of misalignments. The admissible misalignment between inner and outer ring depends on the bearing size, the internal bearing design, the clearance fit, and the acting of forces and moments. Misalignments cause harmful ball movement and produce additional stresses in the bearing which reduce its operating life.

Speed

AUB distinguishes between kinematic limiting speed nG and thermal reference speed nth. The kinematic limiting speed is a practical mechanical limit value and is based on the mechanical fatigue strength of the rolling bearing as a function of its installation situation and lubrication. The limit speed must not be exceeded even under optimum operating conditions without prior consultation with AUB.

The thermal reference speed represents the equilibrium between the heat generated in the bearing by friction and the heat flow dissipated. It is standardised in DIN ISO 15312 (Rolling bearings – Thermal reference speed).

Admissible Operating Temperatures

The admissible operating temperature of a bearing is limited by cage material, dimensional stability of the bearing components (ball race and rolling elements), as well as lubrication. By default, AUB bearings are stabilised up to 200°C (S1). KRW provides roller bearings for higher operating temperatures on request.

Dimensioning

For dynamically loaded bearings

The service life formula according to ISO 281 L10 = (C/P)p for dynamically loaded bearings requires an equivalent load (P) from constant direction and size. To calculate P, calculation factors and the ratio of axial and radial load are required. This is shown in the following equations.

Equivalent Dynamic Bearing Load P

a) Single bearings and tandem arrangement

The equivalent bearing load P for dynamically loaded single bearings or bearings in tandem arrangement depends on the ratio Fa/Fr (axial force / radial force). The equivalent dynamic bearing load can then be determined using the following formula:

P	equivalent dynamic load	[kN]
F_r	dynamic radial force	[kN]
F_a	dynamic axial force	[kN]
e	calculation factor, see chart	[-]
X	calculation factor, see chart	[-]
Y	calculation factor, see chart	[-]

Series	e	X	Y
708, 709, 718, 719	0,80	0,39	0,76
72B, 73B, 74B	1,14	0,35	0,57

b) O- and X-arrangement

The equivalent bearing load P for dynamically loaded bearings in O- or X-arrangement depends on the ratio Fa/Fr (axial force / radial force). The equivalent dynamic bearing load can then be determined using the following formula:

P	equivalent dynamic load	[kN]
F_r	dynamic radial force	[kN]
F_a	dynamic axial force	[kN]
X	calculation factor, see chart	[-]
Y	calculation factor, see chart	[-]

eries	F_a / F_r	X	Y
708, 709, 718, 719	≤ 0,80	1	0,78
708, 709, 718, 719	> 0,80	0,63	1,24
72B, 73B, 74B	≤ 1,14	1	0,55
72B, 73B, 74B	> 1,14	0,57	0,93

Resulting axial force for O- and X-arranged roller bearings

Due to the angular raceways, when a radial force occurs, angular contact ball bearings generate an axial reactive force which is relevant to the bearing dimensioning. When a shaft is supported by two identical or differently sized angular contact ball bearings, the radial load of one bearing produces an axial load for the other bearing. This internal resulting force must be considered when determining the total axial load. The value of the total axial load on a single bearing is determined with the following formulas:

case	load ratio	outer force	resulting axial force F_a
			bearing A	bearing B
1	F_rA/ Y_A≤ F_rB/ Y_B	Ka ≥ 0	F_a= K_a + 0,5 ∙ F_rB / Y_B	F_a is not considered in the calculation
2	F_rA/ Y_A > F_rB / Y_B	K_a > 0,5 · ( F_rA / Y_a– F_rB / Y_B )	F_a = K_a + 0,5 ∙ F_rB / Y_B	F_a is not considered in the calculation
3	F_rA/ Y_A > F_rB / Y_B	K_a ≤ 0,5 ∙ ( F_rA/Y_A– F_rB /Y_{B )}	F_a is not considered in the calculation	F_a= 0,5 ∙ F_rA / Y_A– K_a

To the formulas applies that the bearings being affected by the outer axial force Ka are marked with A and the counter bearings with B. All bearings are backlash-free and considered without preload.

F_rA	radial force in bearing A	[kN]
F_rB	radial force in bearing B	[kN]
Y_A	calculation factor for bearing A (see chart X- and O-arrangement)	[-]
Y_B	calculation factor for bearing B (see chart X- and O-arrangement)	[-]
K_a	outer axial force	[kN]
F_a	resulting axial force	[kN]

c) Reduction of dynamic load rating in a bearing set

For identical angular contact ball bearings assembled directly side by side in X-, O-, or tandem arrangement, the load rating of the bearing set must be reduced. For the dynamic load rating, the following correlation applies:

C_r	dynamic load rating of the bearing set	[kN]
C_{r, single bearing}	dynamic load rating of the single bearing	[kN]
i	number of identical bearings in bearing set	[-]

For statically loaded bearings

Dynamic dimensioning loses its validity for bearings rotating at very low speeds (n x dm ≤ 4000 mm/min). The static load safety factor S0 is calculated as follows:

S₀	static load safety factor	[-]
C₀	basic static load rating (from bearing chart)	[kN]
P₀	equivalent static bearing load	[kN]
n	bearing speed	[min^-1]
d_m	mean bearing diameter [d_m = (D+d)/2]	[mm]

Static load capacity

a) single bearings or tandem arrangement

For statically loaded single row or tandem arranged angular contact ball bearings, the following correlations apply:

F_0r	max. radial static force	[kN]
F_0a	max. axial static force	[kN]

Series	X	Y
708, 709, 718, 719	0,5	0,33
72B, 73B, 74B	0,5	0,26

b) X- und O-arrangement

For statically loaded angular contact ball bearings in X- or O-arrangement, the following correlations apply:

F_0r	max. radial static force	[kN]
F_0a	max. axial static force	[kN]

Series	X	Y
708, 709, 718, 719	1	0,66
72B, 73B, 74B	1	0,52

c) Reduction of static load rating in a bearing set

For identical angular contact ball bearings assembled directly side by side in X-, O-, or tandem arrangement, the load rating of the bearing set must be calculated. For the static load rating, the following correlation applies:

C₀	static load rating of the bearing set	[kN]
C_{0, single bearing}	static load rating of the single bearing	[kN]
i	number of identical bearings in bearing set	[-]

Minimum Radial Load

A minimum load is required for the reliable operation of a rolling bearing. If the minimum load is not reached, slippage may occur. The minimum radial load for angular contact ball bearings is roughly assumed to be 1% of the static load rating C0 of the bearing. If the value falls below this value, consult KRW Application Engineering.

Typical applications of angular contact ball bearings

Due to their ability to accommodate heavy loads, angular contact ball bearings are ideal for heavy machinery and agricultural equipment. These bearings help run pumps, electric motors, gearboxes, steel mills, windmills, conveyor belts and other high speed applications.

FAQs

In which direction do angular contact bearings provide load capacity?

Single-row and tandem ball bearings provide one-directional thrust for axial loads. The contact angle guides the direction, which also determines the gradient of the combined load.

Do angular contact bearings need preload?

To remove excess play during bearing installation, users sustain a load pressure called preloading. Angular contact bearings require preload because they have to work in the pre-defined direction for axial loads.