Zelx SS M18 x 2.5 Spiral Fluted HSS D7 Plug Tap Manufacture YMW Mfg Part Number 372633 Size (Metric) Thread Limit D7 Number of Flutes 3 Chamfered Plug Lead 3 to 5 Finish/Coating Black Oxide Material Vanadium High Speed Steel Oversize (Yes/No) No Length of Thread 1.083 Overall Length (Inch) 4-1/32 Thread Standard UNC