Hobbed M8 Bolt for Wade's Extruder· Material: Stainless Steel· Hobbed Bolt M8 for Gregs Wade Extruder 3mm or 175mm,Reprap Prusa Mendel· The hobbed part of the bolt is 28mm from the center of the hobbed part to the bottom of the head· This M8 Hobbed bolt is used to push the filament into the nozzle and has great driving force· The bolt is an overall length of 65mm, 60 mm from the bottom of the head to the end of the threadsM8 hobbed bolt for a reprap-style 3D printer and Lulzbot Taz 4 3D PrinterHex Head Cap Screw M8 Size, 60 mm Length, 1 mm PitchMade from 18-8 stainless steel, which offers excellent corrosion resistance, these metric cap screws have a Class 6g thread fit and may be mildly magnetic They have a minimum tensile strength of 100,000 psi but are not rated for hardness Screw length is measured from under the head