Shaft can't fit in the hole.

[Adam_JIN]

Hi everyone,

I’m new to this field, so please pardon me if this is a basic question.

I recently submitted two designs—one with ⌀10 holes specified as H7, and another with a ⌀10 shaft specified as h6 (please see the attached drawings). From what I’ve learned, an H7/h6 combination should result in a clearance fit, but when I received the parts, the shaft wouldn't fit into the hole. The shaft length is only 22 mm. I’ve reached out to the manufacturers for clarification. It turns out the shaft and holes were made by two different companies, so I’m waiting to hear back from them.

In the meantime, I just wanted to confirm: is there anything in my design that might have caused this issue? Or is this more likely a manufacturing deviation?

Any advice would be greatly appreciated. Thank you!

 

[3DDave]

The drawing does not appear to be explicit in telling how the holes on opposite sides line up with each other. Many makers would use a single operation to make those holes, but not all manufacturers will - they might just flip the part over and not notice any differences. It is slightly possible the shaft is not straight.

 

[MintJulep]

the shaft wouldn't fit into the hole

Not at all, or not all the way through?

There's possibly burrs on the ID resulting from the M4 thread.

 

[dvd]

What were the actual sizes of received parts? H7/h6 could have been a size-on-size fit, which I would not expect to go. If the saddle was machined after the 10mm hole was bored, there may have been some residual stresses relieved and the hole went out of round - what material was used? Are you located in USA - did the parts suppliers understand what the tolerances meant?

 

[mfgenggear]

OP
the part with the two coaxial holes is lacking true positioning. one hole should be a datum.
the other hole should have FCF true position .
there is nothing that tells the manufacture.
holes are coaxial within .001 inch.
holes will be the correct diameter. but not coaxial. the shaft must be fcf with .001 inch
straightness.
in manufacturing the shaft would require to
be cylindrical ground centerless method.
the both holes would require to be machined in line.
in theory the end of the shaft should fit.
in actually will not due to straightness, roundness, and addition no burrs permitted.

 

[MintJulep]

Guys, it's at 22 mm long shaft. It's not possible for it to simultaneously be in two holes separated by a 65 mm gap.