What Bearing Should You Use for Heavy Loads, Gearboxes and Mining Machinery? A Complete Guide to Tapered Roller Bearings

Tapered roller bearings are separable bearings, with both the inner and outer rings having tapered raceways, and the rollers are frusto-conical in shape. If the tapered surfaces are extended, their apexes meet at a point on the bearing axis, allowing the rollers to achieve pure rolling on the raceways. Tapered roller bearings are mainly used to support combined radial and axial loads with a predominance of radial load, and generally are not suitable for bearing axial load alone. They are suitable for heavy load and impact load applications. The rollers and raceways have line contact; the larger the contact angle, the higher the axial load capacity. These bearings can be classified by the number of roller rows into single-row, double-row, and four-row tapered roller bearings, among other structural types. A single-row tapered roller bearing has one outer ring, while the inner ring and a set of tapered rollers are assembled into an inner ring unit by a cage. It can bear radial load and axial load in one direction, limiting axial displacement of the shaft or housing in one direction. Typically, the cone angle of the outer raceway is between 10°–19°. Bearings with a large cone angle (postfix B, cone angle between 25°–29°) can bear higher axial loads. Double-row tapered roller bearings have an outer ring (or inner ring) as a single piece, with two inner rings (or outer rings) having similar small end faces, and a spacer in between. The clearance is adjusted by the thickness of the spacer. They can bear combined radial and axial loads with a predominance of radial load and can handle axial loads in both directions. Four-row tapered roller bearings have performance similar to double-row bearings but can bear greater radial loads and have slightly lower limiting speeds. They are mainly used in heavy machinery, such as large cold and hot rolling mills. For single-row tapered roller bearings, users can adjust the clearance during installation. For double-row and four-row tapered roller bearings, the clearance is set according to user requirements at the factory and does not need user adjustment. The type designation for tapered roller bearings is 30000, with metric series codes and dimensions conforming to ISO355 standards, and inch series conforming to AFBMA standards. Tapered roller bearings are suitable for bearing radial loads, single-direction axial loads, and combined radial and axial loads. Generally, angle errors are not allowed, but with special design of the rollers and raceways, an angular error of 2′–4′ is permissible. Why choose tapered roller bearings? First, large load capacity: the rollers and raceways have line contact, which can withstand heavy radial and axial combined loads, as well as pure axial loads, making them suitable for heavy-duty and impact load conditions; second, the contact angle determines the axial load capacity. The larger the contact angle, the higher the axial load capacity. Bearings with large cone angles are suitable for conditions where axial loads are predominant; third, separable structure facilitates installation: the bearing components and outer ring can be separated, making it easy to install on the shaft and bearing seat; fourth, adjustable clearance: single-row tapered roller bearings can have their clearance adjusted during installation. When used in pairs, they are arranged in an X configuration, and the installation clearance is adjusted through an outer ring spacer; fifth, wide application range, covering industries such as automotive, mining, metallurgy, reducers, rolling mills, construction machinery, and railways. Tapered roller bearings are mainly used in: wheel hubs, gearboxes, differentials, and drive shaft supports in the automotive industry, where small-size double-row tapered roller bearings are commonly used in the front wheel hubs of cars; crushers, vibrating screens, conveyors, and winches in mining machinery, providing reliable support in dusty and impact environments; input and output shaft supports for reducers and gearboxes, bearing combined radial and axial loads; large cold and hot rolling mills in metallurgy, where four-row tapered roller bearings are mainly used for such heavy machinery; cranes, excavators, and loaders in construction machinery; axle boxes and wheelset supports in railway vehicles; spindles and feed systems in machine tools; as well as motors, fans, petroleum machinery, and other industries. The people who need tapered roller bearings include: automotive parts suppliers and OEM purchasers, mining equipment manufacturers and maintenance teams, reducer and gearbox manufacturers, metallurgical rolling mill equipment manufacturers, construction machinery and railway equipment manufacturers, industrial equipment distributors and bearing inventory holders, maintenance and replacement procurement teams, and overseas EPC contractors. When should tapered roller bearings be selected or replaced? At support points where equipment needs to withstand both radial and axial loads; in heavy-duty or impact load conditions where deep groove ball bearings have insufficient load capacity; for reducers and gearboxes requiring axially locating bearings in pairs; for automotive wheel hubs and gearboxes requiring high-rigidity, high-load bearings; for mining crushers and vibrating screens requiring reliable support in dusty and impact environments; when old bearings are worn, causing increased vibration or abnormal temperature rise and need replacement. Export projects require ISO355 or AFBMA standard interchangeable bearings. How to select tapered roller bearings? Step 1: Determine the type and magnitude of the load, calculate the radial load and axial load; the larger the contact angle, the higher the axial load capacity. Step 2: Determine the structural type: single row for unidirectional axial load (must be installed in pairs), double row for bidirectional axial load, four rows for heavy machinery with extremely large radial loads. Step 3: Determine the size series, select series 30200/30300/32200/32300, etc., based on shaft diameter and bore code. Step 4: Determine the clearance: the clearance of single-row tapered roller bearings is adjusted during installation; for double-row and four-row bearings, it is provided according to user requirements at the factory; when used in pairs, the clearance is adjusted via an outer ring spacer; the suffix code such as A80.120 indicates a clearance of 80–120 μm. Step 5: Determine the accuracy grade: P0 grade for ordinary machinery, P6 or P5 grades for precision reducers and machine tools. Step 6: Confirm the material and cage: GCr15 bearing steel is generally selected under normal working conditions; the standard cage is stamped steel plate, with optional brass or nylon. Step 7: Confirm the mounting fit: tapered roller bearings are designed with adjustable clearance during installation, and the allowable tolerances for shaft and housing are wider. Step 8: Confirm the lubrication method: grease lubrication or oil lubrication, selected according to rotational speed and operating temperature.

Model example: `30206`, meaning a tapered roller bearing; 3 indicates a tapered roller bearing type, 02 the size series, 06 the bore code (06×5=30mm). The old model is 7206E.

Main models and parameters table of tapered roller bearings (example)

Model	Old Model	Bore d mm	Outer Diameter D mm	Total Width T mm	Inner Ring Width B mm	Outer Ring Width C mm	Dynamic Rated Load Cr kN	Static Rated Load C0 kN	Grease Lubrication Limiting Speed rpm	Oil Lubrication Limiting Speed rpm	Weight kg
30202	7202E	15	35	11.8	11	10	19.8	21.0	13000	17000	0.055
30203	7203E	17	40	13.3	12	11	24.0	26.8	11000	15000	0.078
30204	7204E	20	47	15.3	14	12	30.8	33.5	9500	13000	0.120
30205	7205E	25	52	16.3	15	13	34.5	40.0	8500	11000	0.154
30206	7206E	30	62	17.3	16	14	43.0	51.0	6300	8500	0.231
30207	7207E	35	72	18.3	17	15	54.5	65.5	5600	7500	0.338
30208	7208E	40	80	19.8	18	16	63.0	78.0	5000	6700	0.430
30209	7209E	45	85	20.8	19	16	68.0	86.5	4800	6300	0.480
30210	7210E	50	90	21.8	20	17	73.0	95.0	4500	6000	0.540
30211	7211E	55	100	22.8	21	18	90.0	115	4000	5300	0.730
30212	7212E	60	110	23.8	22	19	102	132	3600	4800	0.920
30213	7213E	65	120	24.8	23	20	112	148	3400	4500	1.120
30214	7214E	70	125	26.3	24	21	120	162	3200	4300	1.260
30215	7215E	75	130	27.3	25	22	128	176	3000	4000	1.380
30216	7216E	80	140	28.3	26	22	140	196	2800	3800	1.620
30217	7217E	85	150	30.5	28	24	160	225	2600	3400	2.080
30302	7302E	15	42	14.3	13	11	24.8	24.8	11000	15000	0.094
30303	7303E	17	47	15.3	14	12	29.5	30.5	9500	13000	0.125
30304	7304E	20	52	16.3	15	13	35.2	37.5	8500	11000	0.160
30305	7305E	25	62	18.3	17	15	49.5	54.5	6700	9000	0.263
30306	7306E	30	72	20.8	19	16	63.0	72.0	5600	7500	0.395
30307	7307E	35	80	22.8	21	18	78.0	90.0	5000	6700	0.510
30308	7308E	40	90	25.3	23	20	95.0	112	4300	5600	0.720
32205	7505E	25	52	19.3	18	15	38.5	44.0	8000	11000	0.185
32206	7506E	30	62	21.3	20	17	50.0	58.5	6000	8000	0.280
32207	7507E	35	72	24.3	23	19	68.0	82.0	5300	7000	0.430
32208	7508E	40	80	24.8	23	19	75.0	92.0	4800	6300	0.520
32304	7604E	20	52	22.3	21	18	42.0	44.5	8000	11000	0.210
32305	7605E	25	62	25.3	24	20	58.0	64.0	6300	8500	0.340
32306	7606E	30	72	28.8	27	23	78.0	90.0	5300	7000	0.520
32328	7628	140	300	107.8	102	85	985	1440	1200	1600	33.9

*Data source: General tapered roller bearing size parameter table, subject to actual product catalog. The 30206 bearing has a rated dynamic load of approximately 43 kN, a rated static load of approximately 51 kN, a grease lubrication limiting speed of 6300 r/min, an oil lubrication limiting speed of 8500 r/min, and weighs about 0.231 kg. The 32328 bearing has a rated dynamic load of 985,000 N, a rated static load of 1,440,000 N, a grease lubrication limiting speed of 1200 r/min, an oil lubrication limiting speed of 1600 r/min, and weighs about 33.9 kg.*

General Technical Parameter Table

Parameter	Specification
Type	Tapered Roller Bearing (Single-row/Double-row/Four-row)
Type Code	30000
Bore Diameter Range	15–1100mm (Metric Series); Imperial Series conforms to AFBMA standards
Outer Diameter Range	35–1600mm
Size Series	30200 (Light Narrow)/30300 (Medium Narrow)/32200 (Light Wide)/32300 (Medium Wide)/33000 (Extra Light)/33100 (Extra Light Wide)/33200 (Light Wide), etc.
Structural Form	Single-row (requires paired installation)/Double-row (bidirectional axial)/Four-row (extra high radial load)
Standard Material	GCr15 high-carbon chromium bearing steel
Cage	Stamped steel (standard); optional brass (M), nylon (TN1)
Precision Grade	P0 (Normal set, standard); optional P6, P5
Clearance	Adjusted during single-row installation; double-row/four-row pre-set at factory; outer ring spacer adjustment when used in pairs
Contact Angle	Standard 10°–19°; large cone angle B type 25°–29°
Permissible Tilt Angle	2′–4′ (special design on roller and raceway surfaces)
Seal Type	Open type (standard); optional sealed type (NBR/HNBR/FKM rubber seal)
Lubrication method	Grease lubrication / oil lubrication
Operating temperature	-30°C to +120°C (standard); high temperature type can exceed +150°C
Environmental compliance	RoHS/REACH compliant

Reference for supporting applications (examples)

Application scenarios	Recommended structural type	Recommended series	Typical models	Key requirements
Automotive wheel hub	Single-row paired / double-row	32200/32300	32206/32306	High rigidity, long service life
Automotive gearbox	Single-row paired installation	30200/30300	30206/30306	Axial positioning, adjustable clearance
Gear reducer input/output shaft	Single-row paired installation	30200/32200	30208/32208	Combined radial + axial load
Mining crusher	Double-row / four-row	32000/37000	370000 type	Impact-resistant, heavy-duty
Metallurgical rolling mill	Four-row	370000 type	370000 type	Ultra-high radial load
Construction machinery	Single-row paired / double-row	30200/30300	30210/30310	Impact-resistant, dustproof
Railway axle box	Double-row	350000 type	350000 type	High reliability
Machine tool spindle	Single-row paired installation	30200/32200	30205/32205	High precision P5/P6

The above is an example. The actual selection must be comprehensively calculated based on bearing load, speed, operating temperature, and life requirements.

Dimension drawing placeholder: `[Image: /images/tapered-roller-bearing-dimension-drawing.webp]`

Material table

Component	Standard Material	Optional materials	Description
Inner ring, outer ring, rolling elements	GCr15 high-carbon chromium bearing steel	Carburized steel, stainless steel, ceramics	GCr15 has excellent contact fatigue strength and wear resistance
Cage	Stamped steel plate (No. 10 steel plate)	Brass (M), nylon (TN1)	Brass cages are suitable for impact loads and high vibration conditions
Seal (sealed type)	Nitrile rubber NBR	HNBR, FKM fluoro rubber	Cage made of GCr15 or No. 10 steel plate
Lubricating grease	High-quality lithium-based grease	High-temperature grease, extreme pressure grease	Sealed bearings come pre-filled; open bearings are selected according to operating conditions

Installation fit and clearance adjustment table

Operating conditions	Shaft tolerance	Housing bore tolerance	Clearance adjustment	Description
Normal load, inner ring rotating	k5/k6	H7	Adjust during installation	Most commonly used fit, suitable for gear reducers, pumps
Heavy load or impact load	m5/m6	K7	Adjust during installation	Large interference, needs compensation
Used in pairs (X arrangement)	j5/j6	H7	Outer ring spacer adjustment	Paired bearing suffix code labeling (e.g., A80.120)
Double-row / four-row	Factory specified	Factory specified	No adjustment required	Clearance given according to user requirements at factory
High-precision operation	IT5	IT6	Adjust during installation	Precision reducers, machine tools

Key installation check points: Tapered roller bearings are separable bearings; the inner assembly and outer ring can be installed separately. During installation, ensure that the shaft and bearing seat are clean to avoid dust and foreign objects; tapered roller bearings generally do not allow angular errors, requiring high alignment accuracy, but roller and raceway surfaces are specially designed to allow an angular error of 2′–4′. When used in pairs, arrange in an X pattern; installation clearance is adjusted via the outer ring spacer. Dynamic clearance changes include a decrease of 20–50μm from cold to hot state, and an increase of 5–15μm from no load to full load. Single-row tapered roller bearing clearance is adjusted during installation, while double-row and four-row tapered roller bearing clearance is specified at the factory. After installation, check whether the bearing rotates smoothly and whether there is any sticking or abnormal noise; it is recommended to use special installation tools and strictly prohibit directly striking the bearing.

Application scenario table

Industry	Application	Recommended configuration	Key requirements
Automotive industry	Wheel hubs, gearboxes, differentials, drive shafts	Single-row paired/double-row, 32200/32300 series	High rigidity, long service life
Mining machinery	Crushers, vibrating screens, conveyors, hoists	Double-row/four-row, 32000/37000 series	Impact-resistant, heavy load, dustproof
Reducers	Input and output shaft support, gearboxes	Single-row paired installation, 30200/30300 series	Combined radial + axial load
Metallurgical rolling mill	Large cold and hot rolling mill	Four-row, 370000 series	Extra-large radial load, low-speed heavy duty
Construction machinery	Cranes, excavators, loaders	Single-row paired/double-row, 30200/30300 series	Shock-resistant, dust-proof sealing
Railway vehicles	Axle box, wheelset support	Double-row, 350000 series	High reliability, long life
Machine tools	Spindle, feed system	Single-row paired installation, 30200/32200 series	High precision P5/P6, high rigidity
Motor fans	Motor shaft, fan main shaft	Single-row paired installation, 30200 series	Medium speed, low noise

Note: Tapered roller bearings generally should not bear axial load alone; single-row bearings need paired installation to balance axial force. Extreme contamination or strong corrosive environments require stainless steel material with appropriate sealing. High-temperature conditions require high-temperature grease and proper clearance.

Selection considerations (compared with deep groove ball bearings): The core difference between tapered roller bearings and deep groove ball bearings lies inthe type of load and load capacity. Deep groove ball bearings mainly bear radial load and can also bear a certain amount of bidirectional axial load, suitable for medium load and high-speed general applications, with high limit speed and low friction torque; tapered roller bearings have line contact between rollers and raceways, with higher load capacity, and can bear heavy combined radial and axial loads, suitable for heavy-duty and impact load conditions, but with relatively lower limit speed, usually requiring paired installation. When selecting, tapered roller bearings are preferred for high loads that need to bear both radial and axial loads, while deep groove ball bearings are preferred for light-load high-speed conditions.

## Technical FAQ

1. What is a tapered roller bearing?

Tapered roller bearings are rolling bearings with conical rollers as rolling elements, which are radial-thrust type bearings and belong to separable bearings. Both the inner and outer rings have conical raceways. They mainly bear combined radial and axial loads with radial load as the main load, and are suitable for heavy loads and impact loads.

2. How to read the model of a tapered roller bearing?

The type code is 30000, and the model consists of the type code + dimensional series + inner diameter code. For example: in 30206, 3 is the type of tapered roller bearing, 02 is the dimensional series, and 06 is the inner diameter code (06×5=30mm). The old model is 7206E.

3. What are the main series of tapered roller bearings?

30200 Light Narrow Series, 30300 Medium Narrow Series, 32200 Light Wide Series, 32300 Medium Wide Series, 33000 Extra Light Series, 33100 Extra Light Wide Series, 33200 Light Wide Series, as well as double-row 350000 type, four-row 370000 type, etc.

4. What is the difference between single-row, double-row, and four-row tapered roller bearings?

Single-row can withstand radial load and axial load in a single direction, requiring paired installation to balance the axial force; double-row can withstand axial loads in both directions and are suitable for medium to low-speed applications; four-row has greater load capacity but slightly lower maximum speed, mainly used in heavy machinery such as large cold and hot rolling mills.

5. Can tapered roller bearings withstand pure axial load?

Tapered roller bearings mainly bear combined radial and axial loads with radial load as the main load, and generally should not bear axial load alone. Bearings with a large cone angle (type B) can withstand relatively large axial loads, and when large cone angle bearings are arranged in pairs (installed with the same name ends opposite), they can be used to bear pure radial loads.

6. What is the limiting speed of tapered roller bearings?

The limiting speed depends on the model and lubrication method. For example, for 30206, the limiting speed with grease lubrication is about 6300 r/min, and with oil lubrication about 8500 r/min. For 32328, grease lubrication is 1200 r/min, and oil lubrication 1600 r/min.

7. What is the material of tapered roller bearings?

The standard material is GCr15 high carbon chromium bearing steel, and the standard cage is stamped steel (No. 10 steel sheet), with optional brass or nylon. The sealed type rubber seal uses nitrile rubber NBR, with options for HNBR or FKM fluororubber.

8. How is the clearance of a tapered roller bearing adjusted?

The clearance of a single-row tapered roller bearing is adjusted during installation and is set by adjusting the other bearing paired with it. When used in a paired configuration arranged in an X pattern, the installation clearance is adjusted through the outer ring spacer. The suffix code such as A80.120 indicates a clearance of 80–120 μm. The clearance for double-row and four-row tapered roller bearings is predetermined at the factory and does not require user adjustment.

9. What are the accuracy classes of tapered roller bearings?

The standard is P0 (normal class), and P6 and P5 can be selected. For precision reducers and machine tools, P6 or P5 is recommended, while ordinary machinery can use P0.

10. Can tapered roller bearings be used in automobiles?

Yes, they are core bearing types used in automotive wheel hubs, gearboxes, differentials, and drive shafts. Small-sized double-row tapered roller bearings are commonly used in car front wheel hubs.

11. Can tapered roller bearings be used in mining machinery?

Yes, tapered roller bearings are widely used in mining crushers, vibrating screens, conveyors, winches, and other equipment, providing reliable support in dusty and impact-prone environments. For heavy-duty conditions, double-row or four-row structures are recommended.

12. Can tapered roller bearings be used in reducers?

Yes, input and output shafts of reducers widely use single-row tapered roller bearings installed in pairs, bearing combined radial and axial loads, and the clearance can be adjusted during installation.

13. What is the allowable tilt angle for tapered roller bearings?

Tapered roller bearings typically do not allow angular error, but the roller and raceway surfaces are specially designed to permit an angular error of 2′–4′.

14. How should the fit of tapered roller bearings be selected during installation?

Tapered roller bearings are designed with adjustable clearance during installation, allowing a wider range of permissible tolerances for the shaft and housing. Under normal load with inner ring rotation, select shaft k5/k6 and housing H7. For heavy-duty conditions, select shaft m5/m6 and housing K7.

15. What should be paid attention to when installing tapered roller bearings?

Tapered roller bearings are separable bearings, with the inner assembly and outer ring able to be installed separately. Keep the installation environment clean; when used in pairs, arrange in an X-pattern, and adjust the clearance through the outer ring spacer; use special tools and strictly prohibit directly striking the bearing; after installation, check whether rotation is flexible.

16. What is the difference between tapered roller bearings and deep groove ball bearings?

Deep groove ball bearings primarily bear radial loads and a certain degree of bidirectional axial loads, have high limit speeds, low friction torque, and are suitable for lightly loaded high-speed general situations; tapered roller bearings have rollers and raceways in line contact, with greater load capacity, capable of handling combined radial and axial loads, suitable for heavy load impact conditions, but the limit speed is relatively low and usually requires paired installation.

17. What is the difference between tapered roller bearings and cylindrical roller bearings?

Tapered roller bearings can simultaneously bear combined radial and axial loads, while cylindrical roller bearings primarily bear radial loads, have higher radial load capacity but usually cannot bear axial loads.

18. Can tapered roller bearings be customized?

Materials (carburized steel/stainless steel/ceramic), cages (brass/nylon), accuracy levels (P6/P5), clearances (paired preloaded/paired clearance), sealing types (open/sealed), and special greases (high temperature/extreme pressure) can be customized.

19. How is the service life of a tapered roller bearing calculated?

Bearing life is usually expressed as basic rated life L10, calculated by L10 = (C/P)^(10/3) × 10^6 / 60n, where C is the dynamic rated load, P is the equivalent dynamic load, and n is the rotational speed. The life exponent for tapered roller bearings is 10/3 (for ball bearings it is 3).

20. Do tapered roller bearings comply with RoHS and REACH?

Standard tapered roller bearings comply with RoHS (2011/65/EU) and REACH regulations and do not contain SVHC (Substances of Very High Concern).

Technical FAQ

How do I specify a tapered bearing set?

Provide the bearing number, cup and cone arrangement, load direction, speed, temperature, clearance or preload and lubrication.

Why do tapered bearings need adjustment?

The rolling geometry creates axial positioning requirements. Correct endplay or preload helps control heat, noise and service life.

Authoritative references

For dimensional and quality references, see ISO standards and confirm the exact edition required for your market with the engineering team.

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