Decimal dimension help

I just finished looking at the plans to build Jake's Chair. The dimensions were given in decimal form. There were several decimals though that I didn't recognize such as .9 and .6. How are these measurements figured?

Reply to
euclid69
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"Badly".

You can get strange things like that if the original was in metric units, with a 'clueless' conversion to ft/inches.

And, of course, there _are_ rulers marked in decimal fractions of an inch. Relatively uncommon, but they *do* exist.

If somebody uses 1 decimal place for things in "1/8ths", you typically get decimal parts of: .0 .1 .2 .4 .5 .6 .8 (sometimes .7) and .9

What you're actually dealing with is anybody's guess.

Reply to
Robert Bonomi

I think they are rounded off. .9 is likely .875 or 7/8, .6 is likely .625, or 5/8.

Reply to
Rumpy

That sucks if in inches--if metric, makes sense....

To convert to nearest 8th, 16th or 32nd...

0.9*8 = 7.2 0.9*16 = 14.4 0.9*32 = 28.8

Depending on how anal you are you can choose...

For me, I'd look at the 0.8 and figure it was sorry CAD formatting and figure it was actually 0.875 rounded which would have been 7/8". 0.6 was probably 5/8".

Reply to
Duane Bozarth

Probably converted from metric measurements.

If you want them in fractional inches, multiply by 64 to get 64ths, e.g. 0.9 *

64 = 57.6 so 58/64 or 29/32. Similarly, 0.6 * 64 = 38.4 so 38/64 or 19/32.

Double-checking: 29/32 = 0.906; 19/32 = 0.594. Within six-thousandths each time - probably close enough.

If not, multiply by 128 instead: 0.9 = 115/128, and 0.6 = 77/128 (both accurate within two thou).

Reply to
Doug Miller

An "Engineers Scale" is calibrated in decimel form; however, It is only

12" long.

Not the answer to a maiden's prayer, but used in conjuction with a 12 ft tape, will get the job done.

Lew

Reply to
Lew Hodgett

If they're not rounded then I do it when I made it - just figure .9 is

7/8" and .4 is close enough to 7/16" to not make much difference in building the chairs. It's not a matter of following the actual dimensions in the plans to the decimal point, but making components with the same specs the same dimensions.
Reply to
Fly-by-Night CC

Here's a site that might help.

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O.

Reply to
Mike O.

I've got a 6 footer, marked in 1/100.

Reply to
CW
99.999999% of the time .875 is .88 in 2 decimal places, and one place is most likely .9. Brian.

Reply to
Brian In Hampton

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