(1) A factor not to exceed 80% shall be applied to
static castings that are examined in accordance with the
minimum requirements of the material specification. In
addition to the minimum requirements of the material specification,
all surfaces of centrifugal castings shall be
machined after heat treatment to a finish not coarser than
250 in. (6.3 m) arithmetical average deviation, and a
factor not to exceed 85% shall be applied