dear manger ni hao now wanted special machine tap for this bush ..according to attachment drawing in fact this tap should be 4B . material are =CK45 . .OPERATION BY CNC MACHINE Use coolant when handling MACHINE TAP ----WANTED ..DIN AND FORM TAP ARE BY TAP PRODUCER .. PLEASE CONSIDER AND if your company are able produce inform me your prices for :100pcs 500 pcs and 1000 pcs attention : mu customers wanted 2 or 3 or 5 sample first of all ..(( actually we will pay money for for samples ))if you need more information dont hesitate contact me .mob:00989121023129----whats up-telegram -imo