15PC MAZAK FADAL CAT40 Pull Stud Retention Knob Quality and New Quality Pull Stud Retention Knob Can Be Used On Most MAZAK and FADAL CNC CAT40 Spindle With Coolant Through Hole Made Of High Quality Steel. All blacked. Improves durability. Extends part life. Reduces distortion Professional heat treated. Bad nor non heat treat will shorten and weaken the life and strength of p Retention knob will fit on most of mazak cnc cat40 except VQC 20/40