... type: round, knurled, hexagon, blind5.Sizes:GB-M3 to M12 with metric standard threads UNC 6-32, 8-32, 10-24 ... the products are strictly inspected by operator and skilled QC with record put down.Universal inspection tools: hardness tester, Height ruler, Depth ... , Outside ruler, Venire Caliper, etc. Best service:1.Good communication with every of our customer, especially willing to discuss the details ...