THREAD DEPTH MARKER
When tapping tapered pipe thread for oil or coolant passage plugs in blocks and cylinder heads, it is important not to tap too shallow nor too deep. A length of soft copper wire, twisted around the tap, works much better than tape or a Sharpie mark to indicate the proper depth. The copper wire stays in-place for hundreds of uses, saving engine builders much time and frustration.

Tom Nichols
Automotive Machine & Supply
Joshua, TX 
August, 2022