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hole dimension tolerances on prints 2
- Thread starter bearisle
- Start date
bearisle,
Are you talking about the diameters of the holes, or positional tolerances?
How about...
UNLESS OTHERWISE SPECIFIED, ALL HOLES ARE...
DIAMETER: +.005/-0
POSITION: <DIA>.006 A B C
I am assuming that you are drilling the holes, and that you are using them for small screws, such as less then #10. Your datums are going to have to be A, B and C.
The advantage of standard tolerance notes is speed and convenience. The disadvantage of them is that they save me having to think about stuff that I really ought to have thought about. If I were doing a titleblock in my own drafting office, I would be tempted to _not_ do a tolerance note.
If someone wants to be lazy, they can add their own tolerance note as a note. At least they thought about it. I am getting tired of seeing weldment and sheet metal drawings set to three/two decimal places on English/metric drawings, indicated +/-.005/0.1 tolerances respectively.
JHG
Are you talking about the diameters of the holes, or positional tolerances?
How about...
UNLESS OTHERWISE SPECIFIED, ALL HOLES ARE...
DIAMETER: +.005/-0
POSITION: <DIA>.006 A B C
I am assuming that you are drilling the holes, and that you are using them for small screws, such as less then #10. Your datums are going to have to be A, B and C.
The advantage of standard tolerance notes is speed and convenience. The disadvantage of them is that they save me having to think about stuff that I really ought to have thought about. If I were doing a titleblock in my own drafting office, I would be tempted to _not_ do a tolerance note.
If someone wants to be lazy, they can add their own tolerance note as a note. At least they thought about it. I am getting tired of seeing weldment and sheet metal drawings set to three/two decimal places on English/metric drawings, indicated +/-.005/0.1 tolerances respectively.
JHG
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2
- #3
diamondjim
Mechanical
The are some specs governing drilled hole
size tolerances. The H28 handbook gives
the tap drill sizes and the expected
high sizes for the different thread sizes
and assumes 3 times the diameter for depths.
I have seen a Navy spec for holes in steel.
You can get minus tolerances with aluminum.
size tolerances. The H28 handbook gives
the tap drill sizes and the expected
high sizes for the different thread sizes
and assumes 3 times the diameter for depths.
I have seen a Navy spec for holes in steel.
You can get minus tolerances with aluminum.
diamondjim
Mechanical
Dia. Hole Tolerance
.0135 THRU .125 +.003/ -.001
.1260 THRU .25 +.005/ -.001
.2510 THRU .500 +.006/-.001
.5010 THRU .750 +.008/ -.001
.7510 THRU 1.000 +.010/ -.001
1 .001 THRU 2.000 +.012/ -.001
See the following and check out the
web searching on drilled hole tolerances.
This looks like a good approach.
.0135 THRU .125 +.003/ -.001
.1260 THRU .25 +.005/ -.001
.2510 THRU .500 +.006/-.001
.5010 THRU .750 +.008/ -.001
.7510 THRU 1.000 +.010/ -.001
1 .001 THRU 2.000 +.012/ -.001
See the following and check out the
web searching on drilled hole tolerances.
This looks like a good approach.
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- #5
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