Special flute design improves penetration without blowback or compacting

6 x 2 Phillips Bugle Decking Screws Yellow Zinc Plated - Carton (3500)

5 x 65 Hex Cap Screw 8

0 x 130 Hex Cap Screw 8

the hardness rating is HRC 24-35

8-32 x 3/8 Phillips Flat 82 Undercut Machine Screw Black Zinc Plated (10,000) M24-3.0 Hex Cap Screws 8.8 DIN 931 Zinc Plated Special flute design improves penetration8 32 x 3 8 Phillips Flat 82 Undercut Machine Screw Black Zinc Plated (10,000) . Black Zinc is an acidic, low temperature powdered product developed to impart a black conversion coating of zinc die casting, galvanized stock and electroplated zinc parts. The black coating serves as a base for organic coatings (lacquers, paints, waxes and oils) and also provides an esthetic appeal.