Product Overview BT50 TO MT4 ADAPTER #L123 Protrusion 90mm. Drawbar Thread M24 ITEM(S) 1 pc. BT50 to Morse Taper #4 Adapter APPLICATION For fitting Tools with MT4 Tang Type Shanks to a BT50 Milling Spindle Bore SPECIFICATION 0.01mm (0.0005") Run-Out Tolerance High Grade 1065 Carbon Steel Hardened and Precision Ground Protrusion 90mm M24 Drawbar Thread