Product Description : Please reference drawing.

Thread:1/4" x 37.3 x 8.7 mm / T:1.2 mm
Thread:5/16" x 37.3 x 8.5 mm /  T: 1.2 mm
Thread: M 8 x 37.3 x 8.2 / T:1.2 mm

Material : Steel 

Surface Treatment : Zinc / Yellow Zinc

Washer Function Explanations : This function is mounting on any place you want to support or stay's  furniture or device.