BS 5046:1974

This standard BS 5046:1974 Method for the estimation of equivalent diameters in the heat treatment of steel is classified in these ICS categories:

• 77.080.20 Steels
• 25.200 Heat treatment

1.1 This British Standard provides data for the estimation of the equivalent diameters of pieces of steel of relatively simple shape (hereafter referred to as ‘objects’).

The information is not confined to one type of product, e.g. forgings as distinct from castings or rolled plate, but refers to all objects undergoing a cooling process from an elevated temperature down to ambient temperature by being allowed to stand in still air or by immersion in oil or water.

1.2 The main application of this standard is to the hardening of steels, i.e. to those heat-treatments intended to develop certain desired mechanical properties. It may also be applied to other heat-treatment operations involving similar cooling conditions, where the concept of ‘equivalent diameter’ (as defined in 2.2) is still relevant.

1.3 This standard applies to the following shapes:

1. cylinders and discs;

2. rectangular sections, including plates;

3. rings and tubes;

4. certain axially symmetric shapes with varying cross sections.

1.4 Guidance for the estimation of equivalent diameters for some other miscellaneous shapes is given in Appendix C. Details of the basis used for the calculation have been included in Appendix A.

NOTE. The title of the British Standard referred to in this standard is given on the inside back cover.

Terminology, tables of equivalent diameters for cylinders and discs, rectangular sections, tubes, and rings. Combinations of 2 or 3 cylinders with common axis. Appendices give information on basis of calculation of the tables, two and three cylinder problems, miscellaneous shapes.