Product Description: 1. Perfect Fitment: Set of 8 sockets fits all number and fractional M.C.T.I. standard taps thru 1/2″. Also fits 1/8″ NPT taps and metric taps thru 12mm manufactured to M.C.T.I. standards.A set of taps is very very useful because you can tap a hole for whatever size you need rather than having to weld on a nut or use some other means of fastening. 2. Usage Scenarios: Ideal for situations where a T-handle won’t fit. Choose the socket that closely matches the tap size, insert the tap into the socket until the square end is fully engaged, and then attach the socket to your ¼ or ⅜ square drive tool such as Ratchet Wrench、Electric Screwdriver or Drill. .