1/2-13 x 1 1/2 Slot Ind Hex Wash Taptite Alternative Thread Roll Screw Fully Thrd Zinc & Wax KPU410 meaning they have a flat

meaning they have a flat head and a single-flute thread

This 1/2-13 x 1 Slotted Round Machine Screw is fully threaded and made of zinc

The external sems feature means that the screw has a washer attached

1/4-14 x 5 Unslotted Indented Hex Washer Head Self-Drilling Screw

1/2-13 x 1 1/2 Slot Ind Hex Wash Taptite Alternative Thread Roll Screw Fully Thrd Zinc & Wax KPU410 meaning they have a flat1 2 13 x 1 1 2 Slot Ind Hex Wash Taptite Alternative Thread Roll Screw Fully Thrd Zinc & Wax This screw is a 1 2 13 x 1 1 2 Slotted Independent Hex Washer Head Taptite Alternative Thread Rolling Screw. It is fully threaded and has a zinc and wax coating. This screw is designed to create its own threads in metal, making it ideal for use in applications where tapping is not possible or desired. The slotted hex washer head provides a secure hold and