This swiveling aluminum jig maintains 35mm (1-3/8") hole spacing for guitar tuner string posts or classical machine rollers. Hardened bushings keep the holes straight, perfectly spaced and centered you can use a hand drill!
Clamp the jig on any peghead from 1/2" to 1" thick. Use the supplied 10mm (25/64") bit for classical machines, or the supplied bushings and 1/4" bit for steel-string tuners.