Joined: Apr 2019
Posts: 436
Likes: 124
From: Northern NJ
Bikes: 1987 Pinarello Montello, 1996 Litespeed Classic, 1996 Colnago Master Light, 1997 Litespeed Ultimate, 2006 Opera Leonardo FP, 2006 Pinarello Paris FP, 1984 Pinarello Record, 89-ish Cornelo Profilo, '86 DeRosa Professional SLX, '87 Merckx Corsa Extra
Does M4.5 have the same pitch as M5? If not, when you try to drill and tap M5 where the M4.5 hole is, you will probably end up with a mess - there's not enough difference that the drill will clean out the M4.5 threads completely. If they are both coarse thread they are both .5mm pitch.