Large Dia. Threaded Inserts - Need a Product

[ddeck]

I'm looking for an option to assemble 2 small aluminum parts without having to cut threads in them. The reasons I want to avoid cutting threads in the parts are:
1- the diameter is 1.75" to 2".
2- the thread engagement length is .225"
3- loads are very small
4- reduce cost

Part #1 is a plate with a hollow boss protruding 0.25" with an ID of 1.52" and the OD is to be threaded (want to replace with an off the self part).

Part #2 is a small cylinder type part with a radial flange the will clamp a small gasket to the first part. The Gasket OD has to be 1.75" MIN. The maximum OD of Part #2 is 2.25" (the smaller the better)

So I need 2 threaded parts that I can press on, or bond on to a shaft and to a hole. Material can be plastic since the loads are very low. Fine threads would be nice. Something like screw on a lens to a camera.

Any ideas of an off the shelf part? Or maybe something I could make them out of (that's cheap)?

Thanks!

 

[Tmoose]

Glue ?

 

[ddeck]

Am I on Glue? Or can I use Glue?

What exactly is your question?

 

[tlee123]

It sounds like you need something so that the gasket will be compressed, so an adhesive will require a fixture clamp.

Why not attach the two parts with machine screws in a bolt circle in the flange. You can use a tap to make the threaded holes in one part. For the other part, make the holes slightly oversize so they won't overconstrain the location. Use the boss OD to locate the x-y in a hole in the mating part.

Maybe use 3 screws. Screws and the holes are relatively cheap.

 

[MintJulep]

Go to the supermarket. Buy a jar of pickles. Look at how the lid is made.

 

[GregLocock]

MJ, doesn't a typical lid on a jar rely on the vacuum to keep the gasket tight? Very neat suggestion though.

Tmoose was suggesting glue (or if we are feeling posh Loctite) to hold it together.

is the gasket sealing against external pressure? internal pressure? vapour ? sloshing?

How many are you talking about? 1? 1000000?






Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[MintJulep]

Vacuum enhances the "factory" seal, and keeps to "popper" pulled in, but the wedge/cam/whatever action is tight enough subsequently (for pickles at any rate)

 

[Tmoose]

I'm thinking about using an adhesive or even sealant to assemble (all) the aluminum parts instead of threads and maybe even eliminate the need for a gasket. Obviously I don't know anything at all about the application. Mostly what I heard was cheap, low loads, and about 10-1 diameter to stub length.

If I was making lots of parts, quick might be is as good as cheap, and some of the light curing adhesives are structurally mighty impressive as well as quick. If the "gasket" mentioned is to form a commercial seal around a low speed shaft howsabout gluing a metal cased seal or an elastomer V shaped face seal (forshetta - bad spelling) to the plate?

Snap type assemblies (if suitable) often can replace threads or fasteners.

A few or several Self drilling and tapping fasteners might be used to secure the pieces, and can be cheaper.

If the gasket is soft, plus maybe with a bottoming out feature how about 2 ears and 2 steep ramps, like a Radiator cap? 1/4 turn, which is better than 10 turns to assemble, and no risk of cross thread.

 

[iainuts]

I guess someone has to suggest welding.