Gold melts at
A.1063?C
B.1444?C
C.2100?C
D.3300?C
A.1063?C
B.1444?C
C.2100?C
D.3300?C
A.the pattern is too bulky
B.the pattern is too long
C.the pattern cannot be drawn from mould due to projection
D.the pattern is not made of wood
A.less than that of the casting
B.same as that for the casting
C.more than that of the casting
A.1450?C
B.1260?C
C.1160?C
D.1060?C
A.they do not absorb moisture
B.they are strong
C.they are resistant to wear
D.they have all above qualities
A.round and small
B.sharp and irregular in shape
C.large and regular in shape
D.none of the above
A.poor collapsibility of cores
B.non-provision of camber allowance on the pattern
C.weak flasks
D.any of the above
A.high permeability of sand
B.large grain size
C.soft ramming
D.any of the above
A.Facing sand
B.Floor sand
C.Dry-sand
A.higher temperature of molten iron
B.high efficiency of cupola
C.reduced heat loss in waste gases
D.all of the above