Drywall Screws, Recess Bugle Head, Coarse Thread, Hard.

Drive type: Philips, Torx, Hexagon socket, Square

Core hardness: 289-449HV

Surface hardness: 560-653HV

Surface Treatment: Phosphated

Standard: DIN, ASTM

Certification: ISO9001, CE

Non-standards: OEM is available if you provide the drawing or sample