4 BULLETIX 1259, V. S. DEPAETMEXT OF AGEICULTURE. 
SECTION 6. GRAY-mON CASTINGS. 
1. General. Iron Castings shall conform to the requirements of the 
Standard Specifications for Gray-Iron Castings, Serial 
Designation A4S-18, of the Am.erican Society for Testing 
Materials, ^th subsecjuent amendnaents and additions 
thereto adopted by the society. 
Castings shall be boldly filleted at angles and the arrises 
shall be sharp and perfect. 
2. structural Iron castings shall be true to pattern in form and dimen- 
^^ ■ sions, free from poming faults, sponginess. cracks, blow- 
holes, and other defects in positions affecting their 
strength and value for the service intended. 
SECTION 7. MALLEABLE CASTINGS. 
1. General. Malleable castings shall conform to the requirements 
of the Standard Specifi-cations for Malleable Castings, 
Serial Designation A47-19, of the American Society for 
Testing Materials, with subsequent amendments and 
additions thereto adopted by the society. 
The castings shall be boldly filleted at angles and the 
arrises shall be sharp and perfect. The surfaces shall 
have a workmanlike finish. 
2. structural Malleable castings shall be true to pattern in form and 
^^ ■ dimensions, free from pouring faults, sponginess, cracks, 
■ blowholes, and other defects in positions affecting their 
strength and value for the service intended. 
SECTION 8. PHOSPHOR-BRONZE. 
1. General. Phosplior-bronze shall conform to the requirements of 
the Standard Specifications for Bronze Bearing Metals 
for Turn-tables and Movable Railroad Bridges, Serial 
Designation B22-21, of the American Society for Testing 
Materials, with subsequent amendments and additions 
thereto adopted by the society, 
d f' f}'"^^'^^"^ Bronze castings shall be free from inclusions of foreign 
material, casting fatilts, injtirious blowholes or other 
defects rendering them unsuitable for the service in- 
tended. 
DIVISION II. GENERAL CONSTRUCTION. 
SECTION 1. STEEL STRUCTURES. 
1. Materials. All materials shall conform to the detailed require- 
ments specified in Division I. 
Except where otherwise provided, all members shall be 
of structural steel and rivets shall be of rivet steel. 
Forgings shall be of carbon steel and shall be thoroughly 
annealed before machine finishing. 
Castings shall be of cast steel or cast iron, but, in 
general, cast iron shall be used only for unimportant 
parts. 
Phosphor-bronze may be used in expansion bearings. 
Class A metal shall be used for this purpose. 
