Square Head Screw Full Thread Black-Oxide Alloy Steel 1/2-13 * 4″ Grade 8 [Cup Point] [External Square Drive] Fashion

Use these set screws for light duty holding. A square head allows them to be turned by hand, or fastened with a wrench when you need more torque. The cup point has a thin edge that digs into the contact surface for a secure hold. Length is measured from under the head.