Because of its peculiar composition German-silver solder is related to the ordinary hard solders. Just as hard solders may be regarded as varieties of brass to which zinc has been added, German-silver solders may be regarded as German silver to which zinc has been added. The German-silver solder becomes more easily fused with an increase in zinc, and vice versa. If the quantity of zinc be increased beyond a certain proportion, the resultant solder becomes too brittle. German-silver solders are characterized by remarkable strength, and are therefore used not only in soldering German silver, but in many cases where special strength is required. As German silver can be made of the color of steel, it is frequently used for soldering fine steel articles.

Solder for ordinary German silver can be made of 1,000 parts German-silver chips, 125 parts sheet-brass chips, 142 parts zinc, and 33 parts tin; or, of 8 parts German silver and 2 to 3 parts zinc.

Soft German-Silver Solder

I

Copper........... 4.5 parts

Zinc............. 7 parts

Nickel........... 1 part

II

Copper...........35 parts

Zinc.............56.5 parts

Nickel...........8.5 parts

III

German silver..... 5 parts

Zinc............. 5 parts

Compositions I and II have analogous properties. In composition III German silver" is to be considered as a mixture of copper, zinc, and nickel, for which reason it is necessary to know the exact composition of the German silver to be used. Otherwise it is advisable to experiment first with small quantities in order to ascertain how much zinc is to be added. The proper proportion of German silver to zinc is reached when the mixture reveals a brilliancy and condition which renders it possible to barely pulverize it while hot. A small quantity when brought in contact with the soldering iron should just fuse.

Hard German-Silver or Steel Solder

I

Copper...........35 parts

Zinc.............56.5 parts

Nickel........... 9.5 parts

II

Copper...........38 parts

Zinc.............50 parts

Nickel...........12 parts

Composition I requires a fairly high temperature in order to be melted. Composition II requires a blow pipe.