Handling of Precision Squares

[mgt3]

What is the proper way to handle a precision square like a Starrett No. 20? The No. 20 has an accuracy of +/- .0001. Is any special handling required, apart from not dropping it, keeping it in its box, etc.? Do they hold their accuracy over time?

[eKretz]

Keep it in the box, don't subject it to any sudden jarring, dropping, don't let it rust, etc. Other than that, not much you can do. They generally stay pretty square if they're treated and stored well. Easy enough to check.

[JoeLee]

I have a Starrett 6" square. Had it for over 40 years. It's still accurate but the blade warped / hooked slightly. Starrett said they would fix it but for the price I would look for another.

As far as safe handling, yeah, don't drop it or use it for a welding square. Helps to keep it wiped clean with oil and don't handle it while eating potato chips !

JL..............

[Doozer]

Not related but...
A while ago, we had the guy from Hexagon
come in and do the calibration on the CMMs.
He had a white ceramic 90° angle square in
his tool kit of stuff. Soooo beautiful ! ! !

--Doozer

[mgt3]

I have a Starrett 6" square. Had it for over 40 years. It's still accurate but the blade warped / hooked slightly. Starrett said they would fix it but for the price I would look for another.

As far as safe handling, yeah, don't drop it or use it for a welding square. Helps to keep it wiped clean with oil and don't handle it while eating potato chips !

JL..............

How does the blade warp?

Are some people able to scrape the blade square again?

[Doozer]

Stress.

-D

[BCRider]

Stress.

-D

Just goes to show that shops should pipe in calming nature music 24/7 for the sake of the measurement tooling......

[JoeLee]

How does the blade warp?

Are some people able to scrape the blade square again?

Probably it just moved over time. Scraping it wouldn't do an good. The blade hooked the flat way, not edgewise. I've dressed it on the grinder once and checked it against a master and a couple different ways and it's good.

JL..................

[Doozer]

Just goes to show that shops should pipe in calming nature music 24/7 for the sake of the measurement tooling......

Ha ! ! ! Made me laugh ! ! !

----D

[mgt3]

Probably it just moved over time. Scraping it wouldn't do an good. The blade hooked the flat way, not edgewise. I've dressed it on the grinder once and checked it against a master and a couple different ways and it's good.

JL..................

That’s odd. How would they even fix that? How square can a square be in the xy axis if it’s out in the z axis?

[boslab]

I read that squares respond to a massage with camellia oil, stops them bending in silly directions, I wouldn’t mind it myself just in case of bends
mark

[JRouche]

What is the proper way to handle a precision square like a Starrett No. 20? The No. 20 has an accuracy of +/- .0001. Is any special handling required, apart from not dropping it, keeping it in its box, etc.? Do they hold their accuracy over time?

I dont do super precision stuff, that being said I do have a couple of starrett squares. One large one, about three feet tall and 50lbs lives in its original box. Flat on the ground in a stable (70-75 degrees) environment. I handle it by the base only, never the thinner vertical blade. I wear gloves when touching it as to keep my piss fingers from oxidizing it. Or Ill lube up my hands with WD40 instead. JR

[boslab]

I read that squares respond to a massage with camellia oil, stops them bending in silly directions, I wouldn’t mind it myself just in case of bends
mark

[JoeLee]

That’s odd. How would they even fix that? How square can a square be in the xy axis if it’s out in the z axis?

It's like this.
I also think the slot in the base is slightly off too. But the base is square.

JL................

[mgt3]

Looks like something inadvertently bent it. Hardened steel shouldn’t warp. How would Starrett fix that?