Committees responsible for this Published Document

The preparation of this Published Document was entrusted to Technical Committee ISE/31, Wrought steels, upon which the following bodies were represented:

Confederation of British Metalforming

Institute of Spring Technology

National Association of Steel Stockholders

Society of Motor Manufacturer’s and Traders Association

UK steel Association

Co-opted members

First published November 2001 Second edition January 2005

The following BSI reference relates to the work on this Published Document: Committee reference ISE/31

This Published Document was published under the authority of the Standards Policy and Strategy Committee on 31 January 2005

Foreword

This Published Document has been prepared by Technical Committee ISE/31. It supersedes PD 970:2001, which is withdrawn.

Some errors in PD 970:2001 have been corrected and some steel grades that are in regular use in the UK have been introduced as they did not have equivalents in the newly published European Standards and the withdrawal of BS 970 in which they were listed had resulted in them not being identified within any current document.

BS 970‑1:1996 is to be withdrawn and has been largely replaced by BS EN 10083:1991 (soon to be revised), BS EN 10084:1998, BS EN 10087:1999, BS EN 10088:1995, BS EN 10095:1999 and BS EN 10250‑4:2000.

BS 970‑2:1988 is withdrawn and has been replaced by BS EN 10089:2002. BS 970‑3:1991 is withdrawn and has been replaced by BS EN 10277:1999 and BS EN 10278:1999. BS 970‑4 is withdrawn and has been replaced by BS EN 10090:1998.

The series of European Standards listed below covers heat treatable and engineering steels for both black and cold finished bar that were present in BS 970‑1:1996 and BS 970‑3:1991, or other European Standards.

Steel grades

BS EN 10083‑1, Quenched and tempered steels — Part 1: Technical delivery conditions for special steels.

BS EN 10083‑2, Quenched and tempered steels — Part 2: Technical delivery conditions for unalloyed quality steels.

BS EN 10083‑3, Quenched and tempered steels — Part 3: Technical delivery conditions for boron steels.

BS EN 10084, Case hardening steels — Technical delivery conditions.

BS EN 10085, Nitriding steels — Technical delivery conditions.

BS EN 10087, Free cutting steels — Technical delivery conditions for semi-finished products, hot rolled bars and rods.

BS EN 10088‑1, Stainless steels — Part 1: List of stainless steels.

BS EN 10088‑3, Stainless steels — Part 3: Technical delivery conditions for semi-finished products, bars, rods and sections for general purposes.

BS EN 10089, Hot rolled steels for quenched and tempered springs — Technical delivery conditions.

BS EN 10090, Valve steels and alloys for internal combustion engines.

BS EN 10095, Heat resisting steels and nickel alloys.

BS EN 10250‑2, Open die steel forgings for general engineering purposes — Part 2: Non-alloy quality and special steels.

BS EN 10250‑3, Open die steel forgings for general engineering purposes — Part 3: Alloy special steels.

BS EN 10250‑4, Open die steel forgings for general engineering purposes — Part 4: Stainless steels.

BS EN 10267, Ferritic-pearlitic steels for precipitation hardening from hot working temperatures.

BS EN 10277‑1, Bright steel products — Technical delivery conditions — Part 1: General.

BS EN 10277‑2, Bright steel products — Technical delivery conditions — Part 2: Steels for general engineering purposes.

BS EN 10277‑3, Bright steel products — Technical delivery conditions — Part 3: Free-cutting steels.

BS EN 10277‑4, Bright steel products — Technical delivery conditions — Part 4: Case-hardening steels.

BS EN 10277‑5, Bright steel products — Technical delivery conditions — Part 5: Steels for quenching and tempering.

BS EN ISO 683‑17, Heat-treated steels, alloy steels and free-cutting steels — Part 17: Ball and roller bearing steels.

Dimensions, tolerances and surface quality

BS EN 10058, Hot rolled flat steel bars for general purposes — Dimensions and tolerances on shape and dimensions.

BS EN 10059, Hot rolled square steel bars for general purposes — Dimensions and tolerances on shape and dimensions.

BS EN 10060, Hot rolled round steel bars — Dimensions and tolerances on shape and dimensions.

BS EN 10061, Hot rolled hexagon steel bars — Dimensions and tolerances on shape and dimensions.

BS EN 10092‑1, Hot rolled spring steel flat bars — Part 1: Flat bars — Dimensions and tolerances on shape and dimensions.

BS EN 10092‑2, Hot rolled spring steel flat bars — Part 2: Ribbed and grooved spring leaves — Dimensions and tolerances on shape and dimensions.

BS EN 10221, Specification for surface quality classes for hot rolled bars and rods — Technical delivery conditions.

BS EN 10250‑1, Open die steel forgings for general engineering purposes — Part 1: General requirements.

BS EN 10278, Dimensions and tolerances of bright steel products.

BS EN 20286‑2, ISO system of limits and fits — Part 2: Tables of standard tolerance grades and limit deviations for holes and shafts.

UK Steel Standard UKS01, Semi-finished steel products for the manufacture of hot rolled bar, rod and sections¹⁾[1].

Any steel grade that has previously appeared in BS 970:1983 and is now specified as an equivalent grade in one of the above European Standards is cross-referenced in Annex A which is informative.

This Published Document is not to be regarded as a British Standard.

This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.

Compliance with a Published Document does not of itself confer immunity from legal obligations.

Summary of pages

This document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 43 and a back cover.

The BSI copyright notice displayed in this document indicates when the document was last issued.

1 Scope

This Published Document specifies the technical purchase and supply requirements for the following wrought semi-finished products manufactured from a range of carbon, carbon manganese, low alloy, free-cutting, case-hardening and through hardened steels for the following special applications:

blooms;
billets;
slabs;
bars;
rod;
flats and wide flats.

NOTE These wrought steels may be supplied in the hot formed condition or as thermally treated black bar. Cold finished bar may be subjected to pre- or post-thermal treatment.

It does not specify any boron, micro-alloyed, stainless steels or any products delivered as forgings, which are all covered by other standards (see Foreword).

It does not apply to direct cast products.

PD 970 is presented in the style of a European Standard and references other European Standards (e.g. test methods) wherever possible. The traditional seven digit alphanumeric UK designation is maintained, though it is important to note that the “A”, “M” and “H” system (nominally representing Analysis, Mechanical and Hardenability) should not be confused with other nomenclature. This applies equally to the conventional tensile strength range designations, namely P through to Z which are still used in this document.

Certain other aspects such as requirements for steelmaking, deoxidation and grain size have been revised to reflect modern technology.

2 Normative references

3 Terms and definitions

4 Designation

5 Information to be supplied by the purchaser

5.1 Mandatory information to be supplied at the time of enquiry and order

5.2 Options

6 Manufacturing process

6.1 Melting process

6.2 Deoxidation

6.3 Condition of material on delivery

6.4 Heat treatment

7 Requirements

7.1 Chemical composition

7.2 Mechanical properties

7.3 Technological properties

7.4 Internal soundness

7.5 Surface finish and quality

7.6 Decarburization levels

8 Inspection and testing

8.1 Tensile strength of 1 225 MPa or greater

8.2 Selection and preparation of test bars for tensile and impact tests

8.3 Frequency of other tests

8.4 Test methods and test results

8.5 Types of inspection documents

9 Marking

10 Specific requirements for hot rolled or normalized or softened steels and for steels supplied as cold finished bar

10.1 Specific requirements for hot rolled or normalized or softened steels

10.2 Specific requirements for steels supplied as cold finished bar

11 Specific requirements for quenched and tempered steels including steels capable of surface hardening by nitriding for special applications

12 Specific requirements for case hardening steels

13 Specific requirements for tolerances

13.1 Semi-finished products

13.2 Black bar for special applications

13.3 Black bar for general applications

13.4 Bars for cold finishing

13.5 Cold finished bar

14 Cut end condition

Bibliography

PD 970:2005

Wrought steels for mechanical and allied engineering purposes. Requirements for carbon, carbon manganese and alloy hot worked or cold finished steels

Current, Under Review

Published:

31 Jan 2005