RKB A 4059/A 4138 tapered roller bearing

RKB A 4059/A 4138 belongs to tapered roller bearing, part of our Bearings range. Tell us how many you need by WhatsApp or email and we'll get back to you promptly with a quote for A 4059/A 4138 and any equivalents.

When a shaft has to carry radial and axial forces at the same time and still hold its alignment, a tapered roller bearing is often the answer. The angled rollers and raceways make line contact, which spreads the load across the rolling surfaces. RKB builds this range, and MR supplies it to maintenance and purchasing teams in the United States and Latin America. The example designation below is A 4059/A 4138.

Reading the code helps you order the right piece. RKB uses the standard tapered roller nomenclature, and in the A series the reference is a letter plus a number, as in A 4059/A 4138. That format shows a cone and cup set: the inner assembly and the outer ring each carry their own number. Suffixes that appear on other references point to details of the internal design, such as contact angle or surface finish, so it pays to confirm the full designation before you send your inquiry.

You will find these bearings in gearboxes and transmission cases, speed reducers, machine tool spindles, mining equipment, cranes, agricultural machinery, conveyor rollers and other material handling gear. The combination of combined-load capacity and rigidity suits shafts that must stay precisely aligned while the load changes.

Selection comes down to four things: the radial load, the axial load, the running speed and the conditions around the bearing. Lubrication matters just as much, whether you use grease or oil, and the sealing has to keep contamination out. On installation, align the components carefully and set the internal clearance correctly, using shims or nuts as needed. Poor mounting shortens bearing life.

On interchangeability, tapered roller bearings are made to international standards, so one brand can stand in for another when the main dimensions and the contact angle line up. If you are holding a part number from a different maker, send it over and we will help you locate the matching RKB reference. Checking tolerances and internal clearance is part of getting that match right.

To get a quote, message us on WhatsApp or by email with the part number or the dimensions. MR serves customers across the United States and in several Latin American countries, and the team replies promptly. If the part is unidentified, the main dimensions are usually enough for us to point you to the right reference.