Timken 7200 B 7300 B Single-Row Angular Contact Ball Bearings

Single-row 7200 B and 7300 B angular contact ball bearings

Timken 7200 B and 7300 B single-row angular contact ball bearings carry radial load together with high axial load in one direction. The raceways of the inner and outer ring are offset along the bearing axis, so the balls contact the races along a line at an angle to the radial plane. Timken single-row bearings of the 7200 and 7300 series have a contact angle of 40 degrees, which suits them to applications with heavy axial load such as pumps, gearboxes, machine tool spindles and compressors.

A single bearing locates the shaft axially in one direction only, so these bearings are normally used in pairs. The catalog describes standard single-row bearings and universally matched bearings, which can be mounted in any order and in sets, with a defined axial clearance or preload built in.

Technical specifications

Sample single-row sizes from the catalog table, with bore d, outside diameter D and width B in mm, and dynamic Cr and static C0r load ratings in kN:

Arrangements and designation

Because one bearing resists axial load in a single direction, pairs are mounted back-to-back (DB), face-to-face (DF) or in tandem (DT). The back-to-back arrangement accommodates axial loads in either direction and offers high moment stiffness, face-to-face also takes axial load in both directions with less moment stiffness, and tandem shares an axial load acting in one direction between two bearings.

A full designation reads in order: series code, bore code, contact angle, cage, then optional preload and axial clearance codes. For example 7206 B is a light-series bearing with a 30 mm bore and a 40 degree contact angle, and 7206 BM has a machined brass cage. The related double-row range is listed on the Timken 3200 and 3300 A page.

Cage choice affects speed and temperature behavior. The molded polyamide cage suffixed TN1 is a standard option, while the machined brass cage suffixed M is chosen where heavier loads or higher temperatures are expected. Shields keep out coarse debris at higher speed, whereas 2RS seals retain grease better but run slower, so confirm the closure against the speed and relubrication plan of the application before ordering.

Key features of Timken 7200 B and 7300 B bearings

• 40° contact angle: the steep angle gives a high axial load capacity in one direction, which is why this design is common in pumps, compressors and gear drives with thrust loads.
• Light and medium series: for the same bore, the 73 series has a larger outside diameter and width and carries higher loads than the 72 series.
• Cage choice: machined brass (M) cages tolerate higher temperatures, vibration and poor lubrication well, while molded polyamide (TN1) cages are light and run quietly.
• Sealed and shielded options: ZZ shields and 2RS seals help keep grease in and contamination out where relubrication is difficult.
• Universally matched versions: preload or clearance is built in, so pairs and sets can be mounted without shimming.

Selecting the right bearing

Begin with the shaft diameter and housing space, then check the radial and axial loads against the dynamic and static ratings in the catalog. Because the 40° design takes axial load in one direction only, decide whether the shaft needs location in both directions; if it does, use a matched pair rather than two standard single bearings. Choose back-to-back where tilting moments or shaft deflection must be controlled, face-to-face where some misalignment between housing bores is expected, and tandem where a heavy thrust acts in one direction. For pumps and compressors, the original equipment designation on the old bearing is the most reliable starting point, since the manufacturer has already matched cage, clearance and arrangement to the machine.

Mounting and maintenance

• Mount pairs in the arrangement marked on the bearings or specified for the machine, and never mix bearings from different matched sets.
• Use induction heating or a press with a fitting sleeve on the ring being pressed; never transmit mounting force through the balls.
• Tighten the locknut or end cover to the preload the design requires, then check that the shaft turns freely without axial play.
• Use a lubricant suited to the speed and temperature, and avoid overfilling grease, which raises running temperature.
• Monitor temperature and vibration; a rising trend usually signals lubrication, alignment or contamination problems before failure.

Service in Oman and GCC conditions

Process pumps in oil and gas, water transfer and desalination plants in Oman often run continuously at high ambient temperatures, and sand ingress is a common cause of early bearing failure. Sealed versions or effective housing seals, clean handling during assembly and careful storage in the original packaging all extend life. Where the machine runs hot, check that the cage material and the seal operating temperature limits in the catalog suit the service temperature, and consider shorter relubrication intervals during the summer months.

What to include in your RFQ

• Complete designation including series, bore code, contact angle, cage, closure and matching suffix.
• Quantity of single bearings or matched sets.
• Machine type and application, if the designation is uncertain.
• Photos of the markings on the old bearing.
• Delivery location and required timing.

Documents and quotation

The attached Timken catalog gives the full 7200 and 7300 tables, ratings, nomenclature, mounting arrangements and axial clearance and preload values for universally matched sets. Related bearings are grouped under Electric Motors, Pumps and Turbines. To request a quotation from Seven Star LLC, an independent supplier in Muscat, send the complete designation, cage, arrangement and quantity.