Quality Inspection Of ANSI B18.2.1 Bolts

Production process of high strength blackened ANSI B18.2.1 bolts

Mounting rack → Degreasing with boiling alkali solution → Water cleaning → Derusting with hydrochloric acid solution → Water cleaning → Boiling water heating → Oxidation → Water cleaning → Saponification → Water cleaning → Self-drying → Hot oil dipping → Oil control → Inspection → Storage.

Quality inspection method of high strength ANSI B18.2.1 bolts

Put a high-strength ANSI B18.2.1 bolt under a fluorescent light source, 300mm away from the naked eye, and observe the surface. If the color is uniform and there are no obvious spots and rust, it is good, and the color is black or blue-black.

Determination of oxide film looseness: After degreasing, drop a few drops of 3% copper sulfate solution on the high-strength ANSI B18.2.1 bolts. The copper color is acceptable within 30 seconds.