Measuring Tape Discrepancies ....

[footprintsinconc]

i just bought a kobalt 30ft magnetic measuring tape (used the $10 coupon ) for $14 (original price). so i just thought i would try to measure something in the garage and pulled out the other measuring tape that i had and noticed that there was a 3/32" difference!

now, i pulled out a couple of the other measuring tapes i have and they are real real real close, nothing noticable. so i went back to lowes and exchanged the tape and the difference is still there, but now its like 1/32 or a little more.

one of the other measuring tapes that i have is a stanely, another is a no-name brand from canada.

so questions/conclusion:

1. is this normal or i should just stay clear of kobalt?
2. so this means that when working on a project, no matter what, you should use the same measuring tape through out?

what do you think and what have you noticed?

[drumpriest]

I have had this problem bunches of times. I use 1 tape per project, but even that isn't always enough. Check to see if your tape is off when holding onto the edge vs being pushed against an edge. Most of them are off by quite a bit. Mostly consistency matters, but you should be aware of these issues. Like measuring for a back panel. If you measure the inside distances of a rabbet, then hook onto the edge of your 1/4" ply, you may end up being off...

[Ed62]

I think using the same tape measure for a project is the only way to go. Aside from possible variations in construction, you might have bent the hook a little without realizing it.

Ed

[cabinetman]

The movement of the hook at the end of the tape is for inside and outside measurements. It's supposed to move. The distance of movement is to compensate for the thickness and shape of the hook.
.

[MilDoc]

I agree, one tape per project.

But if at all possible I use precision steel rulers. They don't vary much with temperature while aluminum ones do.

[chopnhack]

Holy cow Batman!
Thank you ever so much for clarifying that mystery for me cabman!!!!
You have no clue - I have been a measuring nazi on all my projects (to myself only of course) and thought that the play in the hook was just the rivets loosening!!! LOL
Again thanks. I never would have known that.


And yes, I too would only use one tape per project - and now I know how to actually use it correctly

[LCHIEN]

FPinC you don't say over what measurement distance that was off by 1/32 or 3/32.

At 30 ft or at 12"?

[eccentrictinkerer]

When I buy a tape I pull out about 5' of the tape and double it back on itself and the check about two 30" sections side by side. You can spot a bad tape pretty quick if the marks don't absolutely line up.

I've been on jobs where, before the workday starts, the foreman will pull out his tape and mark off 6' on a bench. Then each carpenter has to compare his/her tape to the standard. If it doesn't match, they have to find a new one.

[drumpriest]

Cabinetman, apparently not everyone knew that, but I've found many a tape where the amount of movement is incorrect.

[SARGE..g-47]

Same tape always or use a "story stick"..

[Uncle Cracker]

I've been on jobs where, before the workday starts, the foreman will pull out his tape and mark off 6' on a bench.

Hence the term "benchmark"...

[cabinetman]

Cabinetman, apparently not everyone knew that, but I've found many a tape where the amount of movement is incorrect.

The movement amount can be easily checked by hooking the tape to the edge of a board and make a knife mark at a certain length, could be less than 2'. Then set an upright against the edge of the board and push the tape against it and measure to the first mark. They should be the same. If it is off, don't depend on using that particular tape for critical dimensions for inside/outside.
.

[mater]

Although it is probably best to use the same tape on a project I don't. I have several Craftsman tapes lying around my shop and I usually use more than one when measuring. I check them regularly and they are on the money with each other. The way I check them is I cut a board and then check the length with each tape.

[mschrank]

Could just be coincidence, but I picked up a little 16' Kobalt tape to keep in the pocket of my shop apron. I found that, compared to my Stanley's, it's off by about 3/32 as well.

It now resides on my 5-yr olds workbench.

[footprintsinconc]

i didnt think of doubling the tape, but when put next to one another, they are off all locations because of the play at the end. i just checked at 2ft, and 4ft.

its something i will now have to keep in mind when using my tapes, can't loose it till i am not done with the project . i should get a couple of the same brand just in case and make sure they check out as ok against one another.