– Voids left due to solidification freezing. Type III: Sand Inclusions – Sand trapped in molten metal. Type IV: Gas Porosity – Voids caused by entrapped gas. Type V: Veining – Ridge-like features from mold cracking. Type VI: Scabs – Depressions from mold surface buckling.
For those new to it: MSS SP-55 defines the – specifically focusing on surface imperfections and finishing criteria. mss sp55 standard pdf work