Holes oversized, heat treat will help?

[dchu129]

These parts came with oversized hole during deburring of the hole

.128-.1305" holes; currently at .133"

These parts do go to Heat Treat, wondering if the heat treat will help close up that gap of .003"

Material is 17-7 Stainless Steel

Thanks

 

[ornerynorsk]

Very doubtful. That's an enormous order of magnitude of growth/shrink for any material.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[BillPSU]

Place a 1/2-3/4 diameter ball bearing in the hole and tap with a hammer. It will peen the hole closed and the hole will pass inspection using a gage pin.

Be sure to use your calibrated hammer for this operation.

 

[dchu129]

But the holes are only .133"; how do you place .5~.75" diameter ball bearing in the hole; unless you placing on top and hammer it on the surface to peen/flatten surface


Thanks

 

[ornerynorsk]

I think Bill was referring to peening the entrances to the holes, which is not necessarily a good practice because all you are doing is making a portion of the hole come into tolerance, not to mention messing up the surface and probably causing further issues down the line. Likely will not pass inspection if the hole tolerance is indeed critical.

Your best bet might be to re-make the parts. You'll often have more time invested trying to "fix" a part that should have been scrapped, and it brings up issues of workmanship and integrity.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[mcgyvr]

Obviously Bill was joking... The "calibrated hammer" comment should have made that clear.

Remake the parts... Plain and simple.

 

[BillPSU]

I was joking. You will have to remake the parts.

 

[dchu129]

Thought its an untold trick; because flattening the part to get more material in the hole does make sense.

Just gotta see if I can use as is.

 

[Jboggs]

and for what its worth - heating the part makes the holes larger, not smaller. And only while its hot. Duh.