Material: Solid Brass
Thread Diameter: M3 M4 M5 M6 M8 M10
Thread Pitch: M3x0.5,  M4x0.7,  M5x0.8,  M6x1, M8x1.25, M10x1.5
Specification Eg: M3 - 20 ( thread diameter = 3mm, length = 20mm not including the head)