Table 9-2.--Silver Brazing Metals Commonly Used in the Navy
Melting and
Brazing Filler
Grade
Flow Point1
Suggested Use
Shape
Color
No.
Metal
Seal joints operating up to
Strip
Yellow
Silver . . . . . . 20
Copper-silver 0
1430F
1230F. Suitable for
Copper . . . . . 45
joining ferrous metals.
1500F
Zinc . . . . . . . 35
Seal joints operating up to
Nearly
Strip or
Silver . . . . . . 45
Copper-silver I
1250F
white.
1050F. Suitable for
wire.
Copper . . . . . 30
joining ferrous metals.
1370F
Zinc . . . . . . . 25
High silver content
White
Silver . . . . . . 65
strip
Copper-silver II
1280F
primarily for color match.
Copper . . . . . 20
Suitable for joining ferrous
1325F
metals.
Zinc . . . . . . . 15
Gray-
For brazing copper and
Strip or
III
Silver . . . . . . 15
Copper-silver
1200F
white.
wire.
Copper . . . . . 80
1300F
Phosphorous . . 5
For brazing all ferrous and
Strip or
Yellow-
Silver . . . . . . 50
Copper-silver IV
1160F
white.
nonferrous metals except
wire.
Copper . . . . . 15
1175F
those having lower melting
points. Use only where
Zinc . . . . . . . 17
proper tolerances can be
maintained.
Cadmium . . . . 18
For same applications as
Strip or
Yellow-
Silver . . . . . . 50
Copper-silver V
1195F
white.
grade IV but where close
wire.
Copper . . . . . 15
1270F
tolerances cannot be
maintained. For brazing
Zinc . . . . . . . 15
hard metals.
Cadmium . . . . 17
Nickel . . . . . . 3
1
In all instances, the lesser temperature indicates melting point and the higher temperature indicates flow point of the
brazing filler metal.
borax contains approximately 47 percent water of
possibility of bare spots that will oxidize during heating.
crystallization (water that is chemically combined in a
Flux the filler metal by heating the filler rod and dipping
crystallized substance). When the borax is heated, this
it into the flux. Enough flux to do the job will stick to
water is driven off, and the borax appears to boil. Borax
the hot rod.
may be mixed with water to form a paste. However,
Borax or a mixture of borax and other chemicals is
borax can hold water, and it will quickly take up the
most often used as a flux. Up to a certain point, heat
water and become crystalline borax again. If
causes borax to swell and bubble. Common crystalline
9-4