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From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Data sheet detailing the properties and characteristics of the Hiduminium RR.77 alloy.

Identifier  ExFiles\Box 116\2\  scan0136
Date  22th December 1939 guessed
  
Data Sheet No. 39.

HIDUMINIUM RR.77

0.1% Proof Stress
Tons per sq. in.
28—33

Ultimate Stress
Tons per sq. in.
33—38

Elongation
per cent.
16—10

Brinell
Hardness
160—180

HIDUMINIUM R.R.77 is an aluminium base alloy with a specific gravity of 2.8 which has been developed for use in highly stressed structural parts, and is unsurpassed on a yield strength to weight basis by any other material so far available for this purpose.

The alloy represents the result of prolonged research on this subject, and besides its high strength properties, it possesses excellent corrosion resistance, ductility, fatigue resistance and electrical and thermal conductivity.

It is available in most wrought forms such as pressings, extruded and drawn sections and sheet which can be supplied with various heat treatments giving a wide range of mechanical properties. It can be anodised by the usual processes, and with or without this treatment it presents an attractive finish.

Machining and cold forming present no difficulties as the alloy responds readily to those operations used with other high strength alloys.

For the hot working and to a lesser extent for the heat treatment of this alloy, rather different conditions hold as compared with the better known alloys ; however, a large amount of work has been carried out on these problems and a thorough knowledge has been acquired of the peculiarities of the alloy in these respects, in fact, it has been found that parts fabricated from this alloy by the special operations which have been evolved for their production possess greater uniformity of properties in different sections and in different directions of flow than has been possible to obtain with the other wrought light alloys.

It is felt that this alloy with its high strength to weight ratios will prove to be of immense value in solving problems of speed, efficiency and durability, which to-day confront designers and engineers in all progressive industries.

HIGH DUTY ALLOYS LTD.
SLOUGH

Telephone : SLOUGH 21201
Telegrams : “ALLOYS, SLOUGH”

P.T.O.
  
  


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