Chalk or ______________ may be used to rub on the surface of rough castings as a marking material.
a) aluminum sulphate
b) grinding compound
c) paint
d) blue vitrol
e) wax
Answer: D
Chalk or ______________ may be used to rub on the surface of rough castings as a marking material.
a) aluminum sulphate
b) grinding compound
c) paint
d) blue vitrol
e) wax
Answer: D