Rockwell C25-C34

14 x 4 OlyLog® Log Home Fastener (250)

5/8-18 x 2 3/4 Hex Cap Screw SS 316 (A4)

1/4 x 1 1/2 Mushroom Spike Zinc Plated (100)

5/8-11 x 9 Grade 5 Hex Cap Screw Zinc Plated

12-24 x 1/2 Phillips Flat 82 Undercut Machine Screw Black Zinc Plated (7,000) Phillips Flat Undercut Machine Screws Black Zinc Plated Rockwell C25-C3412 24 x 1 2 Phillips Flat 82 Undercut Machine Screw Black Zinc Plated (7,000) . 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.