I also have a collection of small drill bits I keep with my center pins that I use to enlarge the birdseye so I don't split it when trying to match the enlarge bushing on delicate flanges that I don't want to rebush. Rob Edwardsen ----- Original Message ----- From: "Fred Sturm" <fssturm@unm.edu> To: <caut@ptg.org> Sent: Thursday, August 23, 2001 10:48 AM Subject: Re: centered on a tool Hi, Joe, Yes, there's a jump in "imperial" sizes (inches) somewhere between #23 and #24. The jumps become quite large between sizes, as you note, maybe a sort of geometric progression. I keep a few of the larger sizes on hand for emergency use - mostly the odd ancient upright with a couple hammers flopping around. Occasionally the large pin is less work than a rebush (depending on birdseye condition). For high quality work, 22.5 is about the largest size that works, from the point of view of firmness versus friction. I prefer to hold to #22. Larger sizes have too much surface area. And leave too little felt in the hole. Kind of like 5/0 and larger tuning pins - useful in some circumstances, but not recommended where it matters. Regards, Fred Sturm University of New Mexico Joe & Penny Goss wrote: > > Hi all, > In measuring center pins I have discovered that my pins do not always > increase in increments of .001 > They go #18 is .046#18.5 is .047 #19 is .048 19.5 is 49 > #20 is 50 # 20.5 is 51 # 21 is 52 #21.5 is 53 # 22 is > 54. > I do not have any 22.5 pins but presume that they are .055 becuase > #23's are .056 and no #23.5 pins and wonder the size for the #24 pins > are.059 No #24.5 and then #25 is .063 and no #25.5 and the last pin > size 26 is .066 > The break in size progression seems to be between size #23.5 and size > #24 > Question 1. are my missing center pin sizes available? #22.5, 23.5 > and 24.5? > 2. are these larger sizes used by many? {#22 and > larger} > 3.At what size do you deide to rebush rather than > repin? > 4. If larger accurate reamers were available would > you think of using a larger pin size? > Joe Goss > imatunr@srvinet.com > www.mothergoosetools.com
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