stanley tape measure accuracy

[Stwood_]

You sure read  a lot of stuff that is not in a post. Incapable women...
  Where did you come up with that...

[Bill_Houghton]

Might be good for everyone to take a deep breath here before posting next.  There are some comments that could lead to brushfires, and there are enough of those across the country right now.  There are some good points being made - but no one benefits if the points are being "scored."

[Handplanesandmore]

Might be good for everyone to take a deep breath here before posting next.  There are some comments that could lead to brushfires, and there are enough of those across the country right now.  There are some good points being made - but no one benefits if the points are being "scored."

No fires here. Haha.
Simon

[Jim Waldron]

EVERY measuring tape is accurate and correct as long as you stick to the same one. Why would you think your other rulers or tapes are more accurate even if they agreed with each other? Two wrongs do not make a right, remember.

I have several steel rules that are off with each other; same with measuring tapes. The first few inches are fine, but once you compare over 6" or 10" etc, they are off. If you use a tablesaw, I don't think most of your tapes or rulers would match the scale there. The solution? If your tablesaw tape is used to set the cuts, use the tablesaw scale for all other cuts. If you set the fence with a measuring tape, use the measuring tape only for all other cuts.

There is no need to check your tape at all, as long as you stick to it. The industrial jobsite story of people checking their tapes at the beginning of their days is just that -- a story. During my time as a project manager of a construction business overseeing multiple projects of industrial scale, I had never seen one single tradesperson (carpenters, journeymen, stair installers, window installers, kitchen installers, panel cutters, etc.) do that. There was no reliable or meaningful mechanism to set 80 different tapes to the same standard each day! Heck, we engineers did not check our watches when we said we would have lunch at noon before we departed.

Simon

Oh, well, you being an Engineer and all,  
 all that must be accurate and precise!  Myself, I'm just a lowly tradesperson,  
and "we are not worthy."  But I have learned a thing or two over time.  

For example, I know you are just trying to spare us lower beings
the complexities of actual scientific engineering truth  
and haven't wanted to confuse us with dealing with the complexities of accuracy vs. precision vs. observational errors in reading scales vs. tolerances.  Not to mention the effect on a job site from a cold morning to a hot afternoon of ambient temperature and the coefficient of thermal expansion of the particular alloy of the tapes in issue.


I do notice, however, that your collection of minions tradespeople are quite a different lot, in relative functional terms from the cabinet makers and furniture builders who frequent this forum, and who would not be happy with the results of working to the rather loose tolerances of commercial construction projects.  By the same token, those tradesmen would not be entirely happy should you demand that they work to tolerances of 1/64th (expecting no fall-off in productivity, of course).  

About your opening sentence: You stated "EVERY measuring tape is accurate and correct as long as you stick to the same one."  If I may be so bold, didn't you actually mean that tape is precise rather than accurate?  'course, you being an Engineer and all, maybe you know best.  Right?  Right?


Of course I agree wholeheartedly with you on one point: if you're going to rely on tape measures for any dimensions beyond roughing out stock, it is important to know "there can be only one."  
 For myself, once I've got my stock cut to rough dimensions, I put my tape away and use a story stick and dividers and a marking knife and a square.  I work to close tolerances of precision and don't give much thought to actual dimensions, so accuracy is of little or no import.  I fit pieces to other pieces and not to some drawing; all my measurement is relative to the real world and not to some theoretical dimension.  This is not the forum for industrial construction trades.

[Stwood_]

Welcome Jim.

[bandit571]

No fires here. Haha.
Simon

Tis now....

[JimReed@Tallahassee]

For 25 inches I generally use a trammel and transfer the exact measurement. But that is because it is waaaay too easy for me to make a mistake reading the tape.

[Handplanesandmore]

About your opening sentence: You stated "EVERY measuring tape is accurate and correct as long as you stick to the same one."  If I may be so bold, didn't you actually mean that tape is precise rather than accurate?  'course, you being an Engineer and all, maybe you know best.  Right?  Right?

Yes, I do mean accuracy, not precision. Being precise but not accurate is useless, whether in engineering or in woodworking.

But wait, this is not a popularity forum or contest and I am NOT taking the bait. 

I made enough notes about tapes, got to leave the stage for someone else. Perhaps for those who compare tapes first thing in the morning?

Simon

PS Hey, how dare you! By someone's book, I am a "senior" (2011)!... hehe :-) :-) ;-)

[Stwood_]

But wait, this is not a popularity forum or contest and I am NOT taking the bait. 



Simon

PS Hey, how dare you! By someone's book, I am a "senior" (2011)!... hehe :-) :-) ;-)

You out of options, or opinions?
 

Senior? Naw, just a long time lurker that has awoken  ......

[hbmcc]

For a few years my favorite lunchtime haunt was Boeing Surplus, WA. A lot of other people shopped there too. And, the manager was canned, or imprisoned, for selling reject parts to companies peddling them as new. [Wonder if the retail company people went to jail?] The point of my comment:

There were boxes of very nice aluminum 24-inch measuring instruments. There were hundreds--I don't know what they were used for. They were made in China. If y'all know major players with major unions, this type of dipping into the world of slave labor is frowned upon. This type of rejection happens on occasion so less nationalistic entrepreneurs ignore the origin of manufacture. 

I have a fetish for measuring instruments. Since they are nearly all made in the US, a $5 Starrett  is only compared to another $5 Starrett. And, next week may have a better one in the Tool Crib. So I was pretty critical of the Chinese measuring tool. They wanted $2 for one, 6 for $10.

First  issue was difficulty reading the measurements as the mark was about 3/16 th inch from what was to be measured, unless you tip the tool 90 degrees. I decided to wait for day or two, to decide. I have all sorts of measuring sticks, some incredibly valuable ... in 1942.

The next time I had some pocket change to visit BS, I checked the Chinese measures. They were a dollar. And, included a scribbled note: "1/10-inch short!" A tenth over 24 inches is not much. After all, every declination is accounted for. There wasn't an inch missing a tenth; the error is distributed over the length. But, would you buy a pretty measuring instrument that was wrong?

I might use an auto rewind tape measure, but it's only going to be used one way, one direction, one tension, and never another.
And, if multiples of one dimension are called for, the tape is used only once.