Hi, are there standerd demensions for pins and holes?

CAD/CAM/CNC
1

Hi, I just made some holes and pins just like the blue print says, 1.575", and guys comes back and says pins do not fit…so I just make holes bigger. So I am wondering how much bigger the hole should be.?

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May I ask what the dimension was on your finished hole size? Is there a tolerance block of information on the print? If not, I would ask the customer or inspector to provide the limits for the hole or what pin sizes he used to check the part. This should have been clear before machining the part.

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No tolerance on the hole size, (fin hole size was 1.59"), there is tolerance on pin +.000 -.005 that is not near enough to make it fit.

SJ-31-0041.SLDDRW.pdf (564.2 KB)
SJ-31-0113.SLDDRW-1.pdf (560.7 KB)

4

A slip fit is normally +0.001’’/inch of diameter
Light press fit is normally +/- 0.000
A tight press fit would -0.001’’/inch of diameter.

What is on the drawings would give a press to heavy shrink fit. So no, the pins would not push into the hole by hand. The drawing doesn’t give you any fit requirement. If you made the parts to the drawing, they would be difficult to impossible to assemble. You apparently need to be a mind reader.

To make the customer happy, I guess I would make the holes 1.577’’ to 1.580’’. A 1.590’’ hole would be a ‘‘tight’’ clearance hole for a 1.575 pin.

The bottom line is that the dimensions on the drawing are not complete.

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5

Hrere is a liknk to some information on size limits.

I have a adjustable chart i will find and add a link to later.
I run into this a lot with prints. For 5he most part i just say yes ser and fix it.

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6

Found it hear is a link to an adjustable chart for when the engineer gust potts a g G h H tolerance.
http://theoreticalmachinist.com/IsoTolZoneCalc

1 Like
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Drawings are not complete or have enough information. No tolerance for 2 place dimensions, No indication if the mating pin and hole is slip fit or press fit.

8

hi, what would you charge to make a pin like this?

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Since there is no material call out on the drawing, I’ll assume 1020 mild steel. For a one off part, about US$ 20.00

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