Pressure Fit vs Slip fit and glue help

Machine Shop
1

Im wanting to cut holes in aluminum and press fit in a spent 22 cal bullet casing to be flush on the top surface, or just a slip fit and glue each casing in? Any advice on which method and tolerances for a slip or press fitting would be beyond appreciated.

The casing dimensioned below is longer than what i need so i cut them to the length i need.

dom-hole size
dom-hole size1051Ă—567 22.9 KB

hole iso
hole iso691Ă—467 5.97 KB

22 dim

2

I think the slip fit and glue is a better option since the case is tapered. You might even consider a touch of silver solder paste then use hydro flux torch in jewelry to solder it in place. It is high temp, very small flame. The aluminum will soak up the heat fast. Will yield a stronger bond.

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3

What’s the use case? Just a static display? Snug slip fit and Loctite may be all you need.

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4

Loctite has plenty to choose from. All the way up to .02” gap fill. Thats pretty damn loose.
https://www.henkel-adhesives.com/us/en/products/industrial-adhesives/retaining-compounds.html

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5

that sounds like a great plan, any advice on how much gap to leave for a flip fit?

6

thanks so much for the reply i will go the slip fit and loctite route, any advice on how large the hole should be cut for a good slip fit?

7

So up to .020” is pretty loose fitting for metals. Wood, thats a different story. Its really going to depend on what application your going for. If it were holding something over someone’s head, I would go with as tight of a fit as possible which would include reaming the hole to size. If its a static display, drilling to within .010” of an inch would probably be fine. We have gauge pins if you would like to test some drill sizing. The drill size may actually leave a slightly larger size hole than what its listed for. Additionally you may get some wander or taper to the hole.

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8

Closer it is to being a zero gap the more casing rim to metal sheet will be available for bonding. The looser the fit, the less bonding surface. After it dries, I’d flip it, and put a small bead around the case on the inside to help prevent it wigging loose.

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9

thanks so much
i really appreciate it

10

Thank you, much appreaciated

11

if you want a perfect fit use a reamer.

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12

A Machinery’s Handbook is an excellent reference for things like this if it comes up again

13

My first read of this response made me smile. Then I realized I’d misread it.

if you want a perfect fit use a reamer hammer.

I sheepishly admit there are times I’ve used the mis-read approach…

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