Ummmm.....Really? Perplexed here....

[Fastbird]

Bought the 8" x 12" carpenters square @ HF. Yeah, I know, it's only $3.50, and the old post about the calipers that were marked incorrectly sticks out in my mind in relation to this. But......and I'm new to woodworking so don't beat me up too bad if this is normal.......I was using it last night, and on the one side:



All fine and dandy. But on the other side:



How....or why....would you split the 1/4's up into thirds? What use is that?

 

[cptn_zippy]

Uh oh…HF haters are gonna have a field day with this one!

 

[A_Pmech]

You haven't done much roof or stair framing...

That side of the square is divided in twelfths because roof and stair pitch is measured as a multiple of one foot, or 12". Thus, it's a base-12 system.

 

[devoncoolman]

Dont know what the purpous of that would be.

 

[tshetter]

You haven't done much roof or stair framing...

That side of the square is divided in twelfths because roof and stair pitch is measured as a multiple of one foot, or 12".

Base 12, oh the Babylonians would be proud.

J/K

 

[A_Pmech]

Base 12, oh the Babylonians would be proud.

J/K

Yes, exactly. I was trying to think of the correct word. "Base," of course... We posted at the same time.

It's a slow morning.

 

[BFBOB]

Yep, it wouldn't be a proper CARPENTER'S square it it wasn't marked in twelfths of an inch on at least one scale. It does make pitch measurements more convenient and accurate: 4/12 pitch, let's see, that's 1/3", which is no even number of fourths, eighths, sixteenths, 32nds, 64ths or 128ths.

Wait 'til you buy a machinist's square and find it marked in tenths!

 

[Dick in Wisconsin]

I learn something new every time I log onto the GJF!

 

[Shadowdog500]

1:12 scale is also popular for models and miniatures. I bet they love these!


Chris

 

[A_Pmech]

P.S. If you're interested in learning about how to use a square (and all the things you can do with one) a good old text is "A Practical Treatise on the Steel Square" By Fred Hodgson. Published about the turn of the last century.

It can be found online here:

http://www.evenfallstudios.com/woodworks_library/the_steel_square_1.pdf

 

[Fastbird]

Well I'll be danged. Thanks for the education guys! Guess I've got some reading to do. Interesting!