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accuracy of stainless rules

Posted: Thu Oct 26, 2017 12:00 am
by Stray Feathers
I was surprised to discover (during my day job as a picture framer) that in a quick look, there was a discrepancy of as much as 1/32 inch in 24 inches between different stainless measuring scales. One was from a tool store, two were the sort you'd get at a stationery store. I also compared to a couple of tape measures. Having just finished a couple of guitars, I can see that that discrepancy could cause you trouble when laying out necks or fingerboards if you happened to switch rules at some point. It's a reminder that it is good practice to use the same rule for all your work. What I don't know is which of the scales is correct! It would make sense to use one from a luthier supply house, but how do we know they are accurate?

Re: accuracy of stainless rules

Posted: Thu Oct 26, 2017 6:02 am
by MaineGeezer
If you want a reasonable guarantee of accuracy, get a ruler made by Starrett. A 24" ruler is going to set you back over a hundred bucks though.
http://www.starrett.com/metrology/metro ... tBy=wp/asc

Re: accuracy of stainless rules

Posted: Thu Oct 26, 2017 10:05 am
by Danl8
MaineGeezer wrote:If you want a reasonable guarantee of accuracy, get a ruler made by Starrett. A 24" ruler is going to set you back over a hundred bucks though.
http://www.starrett.com/metrology/metro ... tBy=wp/asc
Agreed: Starrett !

Re: accuracy of stainless rules

Posted: Thu Oct 26, 2017 11:30 am
by Diane Kauffmds
Third agree on starrett.

Re: accuracy of stainless rules

Posted: Thu Oct 26, 2017 1:41 pm
by Stray Feathers
Could I borrow your Starrett to check to see which of my scales is accurate?

Re: accuracy of stainless rules

Posted: Thu Oct 26, 2017 6:11 pm
by Diane Kauffmds
Stray Feathers wrote:Could I borrow your Starrett to check to see which of my scales is accurate?
I agree to the starrett, because I know the reputation and I'm buying the 6" at the end of the month. Unfortunately, the 24" is still on my "gotta get" list.

Re: accuracy of stainless rules

Posted: Thu Oct 26, 2017 8:23 pm
by MaineGeezer
Unlike a lot of companies that chemically etch the graduations, or paint them on, Starrett machine engraves the graduations on their rulers.

More accurate...more work....more cost....

Re: accuracy of stainless rules

Posted: Sun Oct 29, 2017 5:39 pm
by tippie53
starret or brown and sharp

there is a difference between a scale and a ruler
you want to buy scales.

Re: accuracy of stainless rules

Posted: Sun Oct 29, 2017 8:06 pm
by MaineGeezer
Unfortunately, Brown & Sharpe is no longer a real company. When the company folded some years ago, the brand name "Brown & Sharpe" got sold. If you by a B&S brand something-or-other today, there is no telling who made it, or what quality it is. Tools made by "Brown & Sharpe, Providence, RI," were among the best, but nowadays it's a crapshoot.

Another old-time company that used to make excellent machinist's tools was Lufkin, but they haven't made machinist's tools in years.

Re: accuracy of stainless rules

Posted: Sun Oct 29, 2017 8:19 pm
by Stray Feathers
Is anyone familiar with GEI rules which claim to be NIST certified? Quite a bit less than Starrett.