White Metals Based On Platinum.—
I.—Platinum, 1 part; copper, 4 parts; or platinum, 1 1/2 parts; copper, 3 1/2 parts.
II.—Platinum, 10 parts; tin, 90 parts; or platinum, 8 parts; tin, 92 parts.
III.—Platinum, 7 parts; copper, 13 parts; tin, 80 parts.
IV.—Platinum, 2 parts; steel, 98 parts.
V.—Platinum, 2.5 parts; steel, 97.5 parts.
IV and V are for gun metal.
Miscellaneous White-metal Alloys.—
I.—For lining cross-head slides: Lead, 65 parts; antimony, 25 parts; copper, 10 parts. Some object to white metal containing lead or zinc. It has been found, however, that lead and zinc have properties of great use in these alloys.
II.—Tin, 85 parts; antimony, 7 1/2 parts; copper, 7 1/2 parts.