UNC Inch Socket button screws stainless, also known as Allen mushroom head screws, are widely used where extreme strength & precision assembly is required. Full & Partial Thread, accordingly to ASME B18.3, ANSI, ASTM, IFI Standard. Also available in high grade alloy steel for performance & SS 316 Grade stainless for superb corrosion advantage. Do CALL US for special material options.