... Grade4.8,6.8,8.8,10.9,12.9 and others you needMaterial 45#, 40Cr, 35CrMoA, 42CrMoA, 25Cr2MoVA, 35VB, 40CrNiMo ... ,Stainless steel and so onSizeM6-M42 LengthM16-300Type of headSquare,Hex,Flange,Hex ... chooseSurface treatmentBlack Oxide,Zinc plated,hot dip galvanized,Dacrotizing plated and your requirementOthersWe can make accroding to your drawing or ...