... Callipers and a Thread Gauge to measure thread pitch.Products Types1.Head Type:Round,Pan,Hex,Flat,Button,Truss,Oval,Binding,Chese ... ,Fillister,etc.2.Drive type: Slotted, Hex, Allen, Torx, Spline Drive, etcMechanical information about our ... with a productive factory, we welcome you to purchase quality products. Come and contact our company now!