Brand: FATH Item: Screw Series: 10 Series, 15 Series, 30 Series, 40 Series and 45 Series For Use With: All T-slotted rails Material: Zinc plated steel Color: Black Quantity per Pack: 10 Manufacturer Part Number: 4DIN7991U1/4-1/2M Head Type: Flat head socket cap Thread Size: 1/4-20 UNC x 1/2in Slot Size: 6/8/10 FATH flat head socket cap screw, black, 1/4-20 UNC x 1/2in, zinc plated steel, slot size 6/8/10. Package of 10. For use with all T-slotted rails. Manufacturer part number: 4DIN7991U1/4-1/2M.