Standards Development

Scope

This document specifies types, dimensions, technical specifications and designation of set screws for insert bearings.

This document is applicable to the production, test and acceptance of set screws for insert bearings.

Purpose

The mounting methods between inner ring of insert bearing and shaft is different from that of common bearings. For insert bearings with eccentric locking collar, concentric locking collar or set screw in the inner ring, set screws are required for mounting. Since set screws for insert bearings are subject to vibration shock and large torque in application, their design, strength, anti-loose performance and reliability will directly affect the performance of insert bearings. Therefore, standardization of set screws for insert bearings is meaningful and necessary for insert bearing industry.

There are some existing international standards specifying boundary dimensions and mechanical performance of common set screws, such as ISO 4029:2003 "Hexagon socket set screws with cup point" and ISO 898-5:2012 "Mechanical properties of fasteners made of carbon steel and alloy steel Part 5: Set screws and similar threaded fasteners with specified hardness classes Coarse thread and fine pitch thread". However, these standards cannot meet special requirements of set screws for insert bearings. After recently communicating with secretariat of ISO/TC2, Fasteners, by Chinese mirrorcommittee, TC2 thinks that fastenings of rolling bearings are very special and not included in the scope of TC2. The purpose of the proposed document is to standardize types, dimensions, technical specifications and designation of set screws for insert bearings. To meet different application, the set screw types will include knurled cup point, W cup point, cup point and ball point, etc, and both metric and inch set screws will be included in this document. To ensure the performance and reliability of set screws, this document will specify technical requirements about material, tolerance, mechanical properties, surface treatment and acceptability. This document will be helpful to the manufacture and inspection of set screws for insert bearing, and thus benefit the insert bearing industry.

The preparation of the proposed document is feasible. It is based on experience of many years of practice in China, such as a Chinese sector standard JB/T 7755 “Rolling bearingsAccessoriesSet screws for insert bearings” (the earliest edition is JB/T 7755-1995).