– Sand trapped in the molten metal showing on the surface.
– Evidence of incomplete fusion of internal supports. mss sp-55 standard pdf
– Small holes or voids from trapped gas. – Sand trapped in the molten metal showing on the surface
: The standard is intended for use on any 4 in. x 5 in. (100mm x 125mm) area of a casting surface. mss sp-55 standard pdf
– Ridges on the surface from mold sand cracking.
– Improper surface prep after a weld repair.