RHP7314CTDULP4Angular Contact Ball Bearing – Straight Bore, 70 mm ID, 150 mm OD, 35 mm Width, Open, 15° Contact Angle, Light Preload.

Product Description

What this part is

A super-precision single-row angular contact ball bearing in the heavy ISO dimension series 03 — 70 mm bore x 150 mm outside diameter x 35 mm width. It is universally ground for light preload, which means it can be combined with like bearings in any arrangement and the preload comes out right without spacer grinding.

Correcting the source data

Two errors in our own earlier listing text are worth naming plainly, because both change what you receive:

The previous description repeatedly called this bearing 7314-C-T-DUL-P4. It is not. The part is SUL, not DUL — Single universally ground, not Duplex. SUL and DUL are ground to different face relationships and are not interchangeable when you are building a defined-preload stack.
The earlier title carried a cross-reference reading 7214X2TAULEP7. That cannot be right for this bearing: a 7214 is a 70 x 125 x 24 mm envelope, whereas this part measures 70 x 150 x 35 mm, which is a 7314. The digit is a transcription slip; the intended designation is the 73-series equivalent. We have removed the contradictory number rather than publish a cross-reference that would send a buyer to the wrong envelope.

Decoding the designation

73 – ISO dimension series 03, the heavy angular contact series — more load capacity and stiffness than a 72xx or 70xx of the same bore.
14 – bore reference, 70 mm.
C – 15° contact angle.
T – laminated phenolic resin cage, outer-ring guided.
SU – single, universally ground.
L – light preload.
P4 – RHP class P4, equal to ABEC 7 and ISO Class 4.

Quantity and configuration

This is one bearing. SUL describes the grinding and preload class of that single bearing, not a set. Because it is universally faced, you can pair or stack it back-to-back, face-to-face or in tandem and the light preload is preserved — mounted in tandem, universally faced bearings share load equally. Order the quantity you actually need for the arrangement you are building.

What these specs mean in practice

The 15° contact angle keeps ball contact nearer the radial plane, favouring speed and low heat generation at the cost of axial stiffness and thrust capacity; a 25° bearing trades the other way. Light preload is RHP’s most-selected level and suits applications where loads and speeds are not extreme.

Preload and arrangement set your speed ceiling as much as size does. Against a single bearing’s limiting speed, RHP derates a light-preload back-to-back pair to 0.80, a set of three to 0.65 and a set of four to 0.60; a face-to-face arrangement is reduced by a further 50%. Choosing medium preload instead drops the pair factor to 0.60, and heavy to 0.40. Grease choice matters too — the tabulated speeds assume a premium high-speed synthetic, and RHP quotes a factor of 1.00 for Klüber Isoflex NBU 15 against 0.83 for Super LDS 18, Topas NB 52 and NCA 15.

The outer-ring-guided laminated phenolic cage is light, stable at speed, quiet and oil-retaining; its constraint is heat, with a maximum recommended operating temperature of 120°C. Rings and balls are through-hardened carbon chrome bearing steel to BS970 534A99/535A99, equivalent to SAE 52100.

Fitting notes

The high point of radial runout is marked — a small circle or burnished spot on the inner ring face and a ‘V’ line on the outer ring OD. Align the marks and oppose them to shaft and housing eccentricity to minimise assembled runout. The ‘V’ also indicates the direction of the contact angle, so it identifies the thrust direction before you press anything home. Deviation from nominal bore and OD is marked in microns on the ring face and repeated on the box end — match grades when building a stack.

Interchange guidance

RHP belongs to the NSK Group, so current-production equivalents are numbered as NSK — search both names for obsolete RHP spindle bearings. The same envelope from other makers is designated 7314C for 15° or 7314A/AC for 25°; confirm which contact-angle scheme a substitute is using, because the same suffix letter denotes different angles across brands.

Published ratings and mounting data

Boundary dimensions, contact angle, class equivalence, cage type and material, preload and arrangement speed factors, grease factors and the 120°C cage limit come from NSK’s RHP Super Precision Angular Contact Ball Bearings catalogue. Per-part basic dynamic and static load ratings and the single-bearing limiting speed live in that catalogue’s numeric bearing tables, which we could not read in full, so those cells are left blank rather than filled from a distributor mirror.