Richard's Machining Tip of the Month
On this page we will provide strategies for accomplishing some of the more difficult machining operations required in the construction of small engines.
Small Tap Guide
Virtually all American made taps from size 6 down to size 0 are made with a shank diameter of .138 inches. This tap guide with its 9/64 drilled hole (.140) will work with all of the small taps typically used in model engineering, from 6-32 down to 0-80, (with apologies to our metric friends). Easily made from aluminum, there isn't a critical dimension on it except for the 9/64 hole.
The base flange measures 2" in diameter by 3/16" thick. The upright portion measures 9/16" diameter by 7/8".
The slot is made with a 1/4" diameter ball end mill and is approximately 1" long by 7/16" deep.
The slot lets you see to position the guide over the hole to be tapped. The wide flange allows one to hold it firmly against the workpiece with one hand while turning the tapwrench with the other.