There are two types of screw surface inspections, one is the inspection before the screw is produced, and the other is the inspection after the screw plating.
Inspection method after screw treatment:
Appearance quality requirements: The inspection of the appearance of the screws is carried out in terms of appearance, plating and other aspects.
Inspection of the thickness of the screw plating: using the gage method, magnetic method, microscopic method, timed flow method, etc.
Inspection of adhesion strength of screw coating: friction polishing test; boring method test; scratch method; bending test; thermal shock test; extrusion method.
Corrosion resistance test of screw coating: method includes atmospheric explosion test; neutral salt spray test (NSS test); acetate spray test (ASS test), copper accelerated acetate spray test (CASS test); and corrosion corrosion of corrosive paste Test (CORR test) and solution drip corrosion test; immersion test, inter-dip corrosion test and so on.
Heavy Hex Bolt，Bolt and Fasteners,Stainless Steel Hex Bolts,Structural Bolt,High Quality Hexagon Bolts,High Stretch Structure Bolt Features of Heavy Hex Bolt A325 Bolt Model Number:ASTM A325 Standard:ASTM Material:Carbon Steel Grade:8S Finish:H.D.G. Certificate:ISO 9001:2008 Head type:Hex Head MOQ:900kgs/size Size:1/2″ to 1 1/2″ Packing:Bulk packed in 25kg cartons then into 900kgs pallet Material: carbon steel Surface treatments: plain, […]
A2-70 Bolt Nut, Stainless Steel Hex Head Screws Bolts and Nuts, DIN, ANSI, ASTM, JIS, BSW Stainless Steel / Carbon Steel Hex Bolt and Nut, din standard galvanized stainless steel special hex head screws washers, bolts and nuts Features of A2-70 Bolt Nut: 1. Certification: ISO, ROHS, SGS 2. Available Standard: DIN, ANSI, ASTM, JIS, […]