Geesh Terry, I knew someone was going to ask that ;-)) The measurement in mm and thou is: My old mic is not the best...so here goes! 480= 1.22mm =.048 thou 485= 1.225mm =.0485 thou 490 =1.245mm = .049 thou 495 = 1.25mm = 500 = 1.265mm 505 = 1.275mm 510 = 1.285mm As there does not seem to be a regular jump in reamer sizes with my mic here are the last two in thou and mm.... I hope! 545 = 1.375mm and .054 thou 550 = 1.385mm and .055 thou I think these reamers are meant for the action parts that this company makes so they might have a limited use on normal action parts. Regards Robin
This PTG archive page provided courtesy of Moy Piano Service, LLC