DS EN 4138:2009 Aerospace Series - Screws, Pan Head, Offset Cruciform Recess, Coarse Tolerance Normal Shank, Medium Length Thread, In Alloy Steel, Cadmium Plated - Classification: 1100 Mpa (At Ambient Temperature)/235 Degree C Defines the characteristics of screws, pan head, offset cruciform recess, coarse tolerance normal shank, medium length thread, in alloy steel, cadmium plated.