This British Standard has been prepared under the direction of the Non-ferrous Metals Standards Committee. It is the second metric revision of BS 2874, which was originally published in 1962 and subsequently revised in 1969 and it supersedes the 1969 edition, which is withdrawn. It is one in a series of standards for copper and copper alloys in various wrought forms, intended for general engineering purposes. The others in the series are:
SS 2870 Specification for rolled copper and copper alloys: sheet, strip and foil
BS 2871 Copper and copper alloys. Tubes
SS 2872 Copper and copper alloys. Forging stock and forgings
SS 2873 Copper and copper alloys. Wire
SS 2875 Copper and copper alloys. Plate
In this revision, due regard has been given to the work of the International Organization for Standardization (ISO) and in particular to Technical Committee ISO/TC 26, Copper and copper alloys, in respect of chemical compositions, testing requirements, properties and dimensional tolerances. Whenever possible and appropriate, the requirements of this standard have been aligned with those of corresponding international standards.
Certain alloys that are considered to be in sufficient demand to warrant inclusion have been added. The additions are:
C 112 copper-cobalt-beryllium
C 113 copper-nickel-phosphorus
CA 107 6 % aluminium-silicon bronze
CC 101 copper-chromium
CC 102 copper-chromium-zirconium
CN 102 90/10 copper- nickel-iron
CN 107 70/30 copper-nickel
CZ 133 naval brass, uninhibited (a modified version of CZ 113, now withdrawn)
CZ 134 naval brass, high leaded
CZ 135 high tensile brass, with silicon
CZ 136 manganese brass
PB 104 8 % phosphor bronze.
The alloy previously known as CZ 123 in BS 2874 has been redesignated CZ 137 to avoid confusion with the similar but purer alloy CZ 123 which is included in BS 2870 and BS 2875.
The demand for nine of the alloys included in the last edition of this standard is considered to be insufficient to warrant their retention and they have consequently been withdrawn. The alloys withdrawn are CA 103, CA 106,
CZ 103, CZ 106, CZ 113, NS 102,NS 111, NS 112 and NS 113.
In this revision, and for the purposes of this standard only, each of the alloys has been placed in one of three material groups, designated I, 11 and Ill, used to specify the dimensional tolerances in tables 5 to 9. The tolerances specified have been reviewed in the light of current demand and practice. Account has been taken of ISO work when revising the tolerances and the break-points.
All mechanical properties have been reviewed and revised where appropriate. All bend test requirements have been
deleted.
In previous editions of this standard, clauses have been included entitled 'Inspection' and 'Facilities for testing', As these clauses are contractual and not relevant to the standard for the product, they have been omitted from this revision.
