bond tiny bushing

I've got an egg shaped hole in the lock frame on my 1919 BMG...
This part is hardened 4140 and its hard to get into the deep hole
anyway so welding it shut and remachining don't look like a good option.
So is there a good way to bond a bushing with a 0.187" OD by 0.150" high into a bore? What would you use? FWIW, if I tried a press fit, it would just break the part.
Karl
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 02 Apr 2012 06:46:18 -0500, Karl Townsend

I think I'd try silver braze.
Pete Keillor
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Den 02-04-2012 13:46, Karl Townsend skrev:

Loctite 638?
--
Uffe Bζrentsen

Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I second that. This would be the stuff to use for loose fitting cylindrical parts with gaps up to .010". For gaps up to 0.015" use loctite 680.
http://www.henkelna.com/industrial/product-search-1554.htm?countryCode=us&language=en&BU=industrial&redDotUID 00000I04
http://www.henkelna.com/industrial/product-search-1554.htm?countryCode=us&language=en&BU=industrial&redDotUID 00000HWK
McMaster has both.
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 4/2/2012 7:46 AM, Karl Townsend wrote:

Can you post a picture or a diagram?
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

http://www.gunbroker.com/Auction/ViewItem.aspx?Item '9377814
in the botton pic, you can see a large diameter hole that soes to small diameter down in there. its egg shaped on mine. lets the trigger sit crooked.
karl
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

nope
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 02 Apr 2012 14:53:28 -0500, Karl Townsend

If it has to be really hard, your options are limited. 4140 tempers over a wide range -- 400 deg. F to 1200 deg. F, with the lower temperatures producing the hardest result, of course. So silver brazing isn't an option unless you can tolerate lower hardness.
Epoxies will give you strength, say, "X". Soft solder, then, is around 2X. Silver braze will be 4X - 12X.
Consider a silver-containing soft solder (maybe 3X or possibly 4X). Some will melt nearer the low tempering range for 4140.
--
Ed Huntress

Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Karl Townsend wrote:

How about reaming it out so it is round. Then press in a hardened piece of steel then bore that to the correct diameter? To ensure the insert cannot come out some loctite bearing retainer would do the trick.
--
Steve W.

Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 4/2/2012 3:53 PM, Karl Townsend wrote:

Call "Red Jacket" and ask them. Maybe they will ask you on the show! http://www.redjacketfirearms.com /
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Drill and tap most of the way through then drive a screw into the tapped hole until it jams, cut off it's head and file flush.....finally, machine a hole down the center of it to suit your pin.
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 3 Apr 2012 23:24:52 -0700, "PrecisionmachinisT"

Damn, that's a good idea. I'll do it that way.
Karl
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

How about a light press fit and lock it in place with LocTite sleeve and bushing locker. Loc-Tite green if I recall correctly.
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

For reference, shear strength of Loctite Green (cured for 24 hours): 3,600 psi. Epoxy, 3,500 - 5,000 psi, depending on type. Soft solder (60/40 tin/lead): 6,000 psi. silver-bearing soft solder: 10,000 - 14,000 psi.
Silver braze is very hard to nail down because of some issues with thickness of joint, wetting, etc. It can range as high as 125,000 psi -- much more than its bulk strength. (Don't ask me how that works; I've never gotten a good answer.) Typical shear strength in practice is 25,000 psi.
--
Ed Huntress

Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

It sounds like high shear strength is not an issue during use, although it may be during assembly if the idea is to hammer a press-fit pin into this bushing. Even then, I have tried to disassemble parts bonded with loctite 603 by pressing and hammering (almost up to the point of damaging the metal) with no luck whatsoever. The only thing that works is high temperatures.
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Monday, April 2, 2012 4:46:18 AM UTC-7, Karl Townsend wrote:

No one else recommended this: rivet the hole closed, with soft iron, or bronze or silver. Then drill your hole in that. I'm not sure how much sidewall you'll get, of course.
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Buy a new one, they WERE fairly cheap. Ohio Ordnance was one source. And what you have depends on the vintage. Some were cast, some(prewar) were machined from forgings and a bunch were made from welded-up stampings. This is a key part of the gun, don't cheap out. It directly controls the timing. If you want to mess with it after you get another, go to it. My experience with them has been that they were harder than hell and I didn't want to have to do anything more with them than I had to to get a legal semi-auto out of the parts kit. I don't think mine were through-hardened, I think they were case- hardened or nitrided. Mess with that sort of thing via welding or silver-brazing and you might get other problems later.
OK, see: http://www.ohioordnanceworks.com/Parts/1919A4FullAutoParts.cat
Stan
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.