Cylindrical, Socket Head Cap Screw, 1/4"-20, Stainless Steel, 18-8, Plain, 1 3/8 in Length/ THREAD DIRECTION: RIGHT-HAND THREAD LENGTH: 1.375 INCHES NOMINAL FASTENER LENGTH: 1.375 INCHES NOMINAL HEAD STYLE: C48 FLAT FILLISTER HEAD DIAMETER: 0.375 INCHES NOMINAL HEAD HEIGHT: 0.25 INCHES NOMINAL HEAD LENGTH: 0.25 INCHES NOMINAL INTERNAL DRIVE STYLE: D17 SQUARE NOMINAL THREAD DIAMETER: 0.25 INCHES WIDTH ACROSS FLATS: 0.187 INCHES NOMINAL THREAD QUANTITY PER INCH: 20 HOLE CONFIGURATION STYLE: E16 SQUARE FLATS PART NAME ASSIGNED BY CONTROLLING AGENCY: SKT CAP SCRW, STD, 18-8,1/4-20X1-3/8, PK25 SPECIAL FEATURES: TEMP RANGE -65 DEGREES F TO 300 DEGREES F MEETS/EXCEEDS ASME B18.3 AND ASTM F837 MIN. TENSILE STRENGTH 80,000 PSI ROCKWELL HARDNESS B81 TO B100. COLOR: SILVER OVERALL MATERIAL: STEEL PROPERTY CLASS 18.8 OVERALL