Five-Size Hand Tap Guide Block
A bench jig that holds a hand tap perpendicular to the work while you start the thread, with five guide towers bored 3.4 / 4.5 / 5.5 / 6.6 / 8.6 mm for M3, M4, M5, M6 and M8 taps. Each bore is 30 mm long (a ~9:1 guide ratio on M3) with a 2 mm funnel counterbore at the top; the 116 x 40 x 5 mm base sits flat on the workpiece and has four 5.5 mm holes for M5 clamp screws, and 1-to-5 tally grooves along the front edge mark which tower is which.
tool jig tapping threading