PROCUREMENT EXECUTIVE D.T.D.
5087
MINISTRY OF DEFENCE January 1975
Aerospace Material Specification
NICKEL-CHROMIUM-COBALT-ALUMINIUM-TITANIUM
HEAT-RESISTING WIRE
(not exceeding 2mm diameter)
(Suitable for locking wire)
NOTE: This specification is one of a series issued by the Procurement Executive, Ministry of Defence to meet a
requirement not covered by an existing British Standard for aerospace material.
1. INSPECTION AND TESTING PROCEDURE
This specification shall be used in conjunction with British Standard HR.100, Sections 1 and 7.
2. MANUFACTURE
Unless otherwise agreed, the material shall be manufactured by one of the following processes:
(1) Induction melted, vacuum refined and cast in air.
(2) Consumable electrode remelted.
3. CHEMICAL COMPOSITION
The chemical composition of the material shall be:
Per cent
Element
Minimum Maximum
Carbon - 0.13
Silicon - 1.0
Manganese - 1.0
Sulphur - 0.015
Silver - 0.0005(5ppm)
Aluminium 1.0 2.0
Boron - 0.020
Bismuth - 0.0001 (1ppm)
Cobalt 15.0 21.0
Chromium 18.0 21.0
Copper - 0.2
Iron - 1.5
Lead - 0.0020(20ppm)
Titanium 2.0 3.0
Zirconium - 0.15
Nickel Remainder
4. CONDlTlON
The wire shall be supplied in the fully softened and descaled condition.
5. HEAT TREATMENT
The material shall be heated uniformly at a temperature within the range 1100°C to 1150°C followed by
5.1 Wire up to and including 1.6mm diameter or minor sectional dimension shall be heated uniformly at a
temperature within the range 1100°C to 1150°C in a protective atmosphere, followed by cooling in a
water cooled zone under the same protective atmosphere.
5.2 Wire greater than 1.6mm diameter or minor sectional dimension shall be heated uniformly at a
temperature within the range 1100°C, to 1150°C, followed by quenching in water.
6. SPECIAL MECHANICAL TESTS
Samples selected in accordance with the requirements of BS.HR.100,7.5.3 shall be taken from wire heat-treated
in accordance with clause 5 of this specification and tested as follows:-
(1) Wrapping test. A test piece, prepared from the sample shall be tested in accordance with BS.HR.100,
l.20.1.3.
(2) Reverse bend test. A test piece prepared from the sample shall be tested in accordance with BS HR.100,
1.20.1.4 (ignoring the restriction of the test to wires over 2mm diameter) and shall withstand, without
cracking, three bends over a former radius equal to three times the diameter of the wire.
7. TOLERANCES ON DIMENSIONS OF WIRE
The following tolerances on diameter shall apply:
Nominal wire diameter Tolerance
mm mm
0.50 ± 0.04
0.80 ± 0.04
Approved for issue,
N. L. PARR,
Director of Research Materials.
© Crown Copyright 1975
Printcd in England by Hobbs the Printers Ltd., Southhampton SO9 2UZ
and published by Her Majesty’s Stationery Office
6p Net
(239) Dd288813 K11 3/75
ISBN 0 11 771619 7
