machine bolt 1.material: stainless steel,steel 2.free sample, more than 10 years supplier 3.ISO,SGS certification 4.Canon Machine Bolt A: SpecificationMaterial:stainless steel, aluminum,carbon steelSurface Finish:nickel plated,white zinc,black zinc,color zinc,black oxidemetric and inch sizesize: M4-M33packing:carton box,poly bag and paper bag,or according to the cutomers'requirementStandard:DIN, ...