Tapered Roller Bearing

A tapered roller bearing has tapered inner and outer ring raceways and tapered rollers between them, so it carries radial and axial load at the same time [1]. In the trade it is also called a taper roller bearing. As a tapered roller bearing manufacturer, FULI supplies ten ISO series, from 30200 to 33200, and inch sizes, from our factory in Linqing, Shandong; our bearing manufacturer page shows the other types we make. Below: how the series differ, how to read the size chart, what the cup and cone are, and what to check before a wholesale or OEM order.

Tapered roller bearing range and series at FULI

The size table above lists every size on this site with its bore (d), outside diameter (D) and total width (T). The first three digits of an ISO number give the series, and the last two digits are the bore code. All the series below are single row designs.

Series	Bore range on this site (mm)	Proportions for the same bore	Sizes on this site
30200	15 to 140	Light series	24
30300	15 to 95	Medium series, larger outside diameter and width	18
31300	25 to 90	Same envelope as 30300, steeper contact angle	14
32000	20 to 170	Small outside diameter, wide	29
32200	20 to 140	Same outside diameter as 30200, wider rings	22
32300	15 to 100	Same outside diameter as 30300, wider rings	18
32900	20 to 170	Thin section	24
33000, 33100, 33200	25 to 120	Wide, high capacity for the space	47
Inch cone and cup pairs	15.875 to 114.3	Each ring has its own number	165 pairs

A 32200 bearing fits the same housing bore as the 30200 bearing with the same bore code, but it is wider, so it has longer rollers and more capacity. A 30300 bearing needs a larger housing bore. Inch sizes such as LM11949 and L44649 follow the ABMA system, where each ring carries its own number; the number lookup matches the two. Model pages give the full dimension set and, where published, FULI’s catalog load ratings.

Single row tapered roller bearing

In this design the projection lines of the raceways meet at one point on the bearing axis, which gives true rolling of the rollers [1]. The axial capacity rises with the contact angle, which is usually between 10° and 30° [1].

A single row bearing takes axial load in one direction only. For that reason it is normally mounted against a second bearing, face-to-face or back-to-back, and the two are adjusted against each other [1][2]. The internal clearance is not a fixed C-class value as on a ball bearing. It is set during mounting, by adjusting one bearing axially against the other [1][2].

The setting matters, and the optimal value depends on speed, temperature and fits. If the operating clearance is too large, the bearings cannot carry their full rating. If the preload is too high, friction and heat go up and service life drops [1]. The allowed misalignment is also small, a few minutes of arc [1], so the shaft and housing seats need to be in line. The bearing internal clearance guide explains both settings in more detail.

Taper roller bearing geometry

Each rolling element has a conical shape, so it can rotate without skidding. Its large end runs against a rib on the inner race, which guides it and holds it in place. Contact with the rings is along a line, not the point contact of a ball, so the elements distribute force along their full length. This is why, among rolling element bearings, taper designs suit heavy duty work in a compact envelope. The contact angle sets the balance: a steeper cup taper, as in the 31300 series, takes more thrust and less radial force [1].

Lubrication, materials and operating conditions

Grease suits most wheel hubs and units at moderate speed. Gear drives run the bearings in the same oil as the gears. The roller ends slide on that rib, so this contact needs a good oil film for low friction; a dry rib wears first and lets the setting drift. See grease choice and intervals.

FULI taper bearings are open, with no seals, so in a wet or dirty environment the housing needs its own seals. The rings and rolling elements are hardened steel with a ground running surface. Where these bearings are used in hot, fast or shock operating conditions, check the setting after the first run, because a correct setting is what gives long life and reliability.

Tapered roller bearing size chart

Metric taper roller bearings follow the boundary dimensions of ISO 355 [1]. As with ball bearings, the bore code is the last two digits: from 04 upward, multiply the code by 5 to get the bore in mm. The table gives D x T in mm for bore codes 04 to 12; larger and smaller bores are in the size table above.

Bore code	Bore d (mm)	30200 series (D x T)	30300 series (D x T)	32200 series (D x T)
04	20	47 x 15.25	52 x 16.25	47 x 19.25
05	25	52 x 16.25	62 x 18.25	52 x 19.25
06	30	62 x 17.25	72 x 20.75	62 x 21.25
07	35	72 x 18.25	80 x 22.75	72 x 24.25
08	40	80 x 19.75	90 x 25.25	80 x 24.75
09	45	85 x 20.75	100 x 27.25	85 x 24.75
10	50	90 x 21.75	110 x 29.25	90 x 24.75
11	55	100 x 22.75	120 x 31.5	100 x 26.75
12	60	110 x 23.75	130 x 33.5	110 x 29.75

Every size in this chart has a model page. To identify an unmarked bearing, measure the bore of the cone, the outside diameter (OD) of the cup and the total width with the two parts assembled, then match the three numbers against the chart.

The 30205 bearing and the 32205 bearing show how series change the size on the same 25 mm shaft: both have a 52 mm outside diameter, but T is 16.25 mm for 30205 and 19.25 mm for 32205.

Taper roller bearing cup and cone

A single row bearing of this type comes apart into two pieces. The cone is the inner ring together with the rollers and the cage. The cup is the outer ring [1]. The cone and the cup can be mounted separately, which makes mounting, dismounting and inspection easier [1].

Within one maker’s range, a cone and a cup with the same basic designation are interchangeable, and the total width T stays within tolerance when they are swapped [1]. A cup or a cone can also be supplied on its own [1]. The cup raceway and the rollers run against each other, so if the cup is pitted or worn, check the cone as well before you decide to replace only one part.

FULI bearings are supplied open, as a complete set. If you need only one part, state which and the full number in the inquiry, and we will confirm it with the quote.

Double row tapered roller bearing

A double row design puts two rows in one unit. In the TDO design, one double cup runs with two cones; in the TDI design, two cups run with one double cone [1][2]. Both carry heavy radial load and axial load in both directions. They are usually supplied with a spacer as a pre-set assembly [2]. Typical uses include gearboxes, hoisting equipment, rolling mills and mining machines [1]. Four rows, as two double-row units, are used on rolling mill roll necks [1].

Two single row bearings can also be supplied as a matched pair. A pair set in either of these two arrangements takes axial load in both directions; a tandem pair shares it equally between the two bearings and works in one direction only [1].

FULI lists single row sizes on this site. If your drawing calls for a double row bearing or a matched pair, send the designation and we will confirm availability with the quote.

Taper roller bearing dimensions: d, D, T, B and C

This bearing type needs five dimensions to describe it, not three:

• d: bore of the cone, which is the shaft diameter.
• D: outside diameter of the cup, which is the housing bore.
• T: total width with cup and cone assembled. This is the figure in the size table and size chart on this page.
• B: width of the cone.
• C: width of the cup.

T is the number that decides the space the bearing takes on the shaft. B and C matter when you machine shaft and housing shoulders, or when you replace only one part. B is not always the same between makers for the same number: for 30304, it is 15 mm at some makers and 16 mm at others, as the cross reference pages note. Check B against your drawing if the shoulder position is critical.

The designation also carries a dimension series. Under ISO 355, a digit for the contact angle range and two letters for the diameter and width series describe the shape of each bearing [1]. For ordering, the bearing number such as 30205 is enough; the series code is printed in some maker catalogs.

Interchange with other brands

A number such as 30205 is an ISO designation, so d, D and T are the same whichever manufacturer made it. Makers add their own prefixes and suffixes for design, cage or tolerance. The Timken tapered roller cross reference lists 18 common sizes with the SKF, Timken, NSK, NTN, Koyo and FAG numbers, and the bearing cross reference hub covers the other bearing types.

SKF, Timken, NSK, NTN, Koyo and FAG are trademarks of their respective owners. FULI is not affiliated with, authorized by or endorsed by any of these companies. Part numbers are shown for interchange reference only. FULI dimensions, load ratings and speeds come from the FULI catalog.

Typical applications

Tapered roller bearings are used where combined forces act and there must be no end play:

• Vehicle wheel bearings, axles and differentials. See tractor bearings.
• Transmissions and motor-driven reducers. See gear drive bearings.
• Farm machinery wheels. See agricultural machinery bearings.
• Industrial machinery such as conveyor pulleys, crane wheels and machine tool spindles.

What to check before you order

Because the boundary dimensions are standardized, a 30205 from one source fits the same shaft and housing as a 30205 from another. The points below are what the dimensions do not show. Ask for them in writing before a first order, whoever you buy from.

1. Steel grade. FULI cups, cones and rollers are GCr15 chrome bearing steel; the steel maker’s material certificate is available on request for OEM and industrial orders.
2. Precision class. P0 is standard and P6 is on request. State the class on the order.
3. Cone width B, if your shaft shoulder depends on it (see the 30304 note above).
4. Load ratings. The model pages list FULI’s catalog dynamic and static ratings where they have been checked. They are not fixed by the ISO number, so compare them between suppliers.
5. Inspection scope. A FULI inspection report normally covers dimensions, rotation noise, vibration, appearance, material certificate and batch traceability.
6. Export documents: commercial invoice, packing list and CCPIT certificate of origin, plus an FTA Form COO where the destination country qualifies.

If you are still choosing between a taper roller bearing and a ball bearing, the ball bearing vs roller bearing guide compares them by load, speed and fitting. For mainly radial load with no adjustment, see the deep groove ball bearing range; for heavy radial load with shaft misalignment, see the spherical roller bearing range.

Specifications and dimensions FULI supplies

Item	FULI specification
Series	30200 to 33200 (ten series), plus inch pairs
Bore range	15 to 170 mm on this site (inch pairs 15.875 to 114.3 mm)
Design	Open, cup and cone, no seals
Material	GCr15 chrome bearing steel, rings and rollers
Precision	P0 standard; P6 on request
Internal clearance	Set during mounting (adjustable, not a C-class value)
Dimensions	d, D and T to ISO 355
Load ratings	Cr and C0r from FULI’s catalog on the model pages

To get a quotation, send the bearing number (for example 30205 or 32207), the quantity per size, the bearing application and the destination port to sales@fuli-bearings.com or use the request a quote form. If you need only cups or only cones, say so in the same message.

Sources

1. https://www.skf.com/binaries/pub12/Images/0901d196802809de-Rolling-bearings---17000_1-EN_tcm_12-121486.pdf
2. https://www.timken.com/wp-content/uploads/2016/10/Timken-Engineering-Manual_10424.pdf