MIM parts?

[1911Tuner]

Why, yes! Yes we have!

Me. Fuff. Keenan. Did dfarriswheel post yet? Him too.

Why do you ask?

 

[tekarra]

The binder in MIM is only to hold the metal particles together whilst the part is in its green form. That is until the part is transferred from the mould to the sintering furnace. In the sintering furnace, the binder is volatilised and the surface of the particles melt and fuse with adjoining particles. Sintering temperature is critical to the process as too low a temperature will result in non-fused parts and too high a temperature will result in puddle in the furnace. As noted in a previous post, MIM is a powder metallurgy process.

 

[psyshack]

I asked because I to have worked both in revolvers and autos. And I'm really starting to like the MIM. The nightmare comments I had heard over the years really scared me. And I rode the wave knowing how MIM was years ago. I was raised in custom tooling and metallurgy. My father in-law owns a foundry and machine tool co.

I've been impressed with the MIM. It's taken to the stones very nice. It's held what I've done very well. And has looked good under magnification.

One thing that has upset me is the tolerance of the machined studs the hammer and say trigger rotate on. At first I was thinking it was the pivot holes in the parts being to sloppy. No it's the studs they ride on. They can't seem to get them straight at times much less the dia. right. IMHO

And I for a fact know S&W isn't the only American co. that can't seem to run a tool room worth a crap.

But maybe I got it all wrong.

 

[madcratebuilder]

I've been impressed with the MIM. It's taken to the stones very nice. It's held what I've done very well. And has looked good under magnification.

One thing that has upset me is the tolerance of the machined studs the hammer and say trigger rotate on. At first I was thinking it was the pivot holes in the parts being to sloppy. No it's the studs they ride on. They can't seem to get them straight at times much less the dia. right. IMHO

I've had the same results with the MIM parts I have stoned on my revolvers. My concern was if I would see increased wear but so far it is normal.

 

[1911Tuner]

Quote:

>And I for a fact know S&W isn't the only American co. that can't seem to run a tool room worth a crap. <

And that's a fact, Jack.

 

[Jim K]

Unlike the old "forged" S&W parts (which for many years have been blanked from sheet steel), MIM parts are not case hardened, they are hard all the way through. So stoning them won't cut through a thin layer of hardness leaving a soft surface. The MIM parts I have seen seem to be very smooth, without the tool marks common to the old method of manufacture, and don't really need work. But of course some folks, confronted with any gun part, always grab a stone or a file, thinking they can improve something. Maybe they do, and at least the MIM part won't be ruined by stoning.

Jim

 

[918v]

Can you plate MIM with NP3 or similar nickle?

 

[Guillermo]

Can you plate MIM with NP3 or similar nickle?

The hard chrome on the Jerry Miculec 625 trigger does not stick well according to Grant Cunningham.

With this in mind I would ask not only can it be done but also inquire about durability.

 

[918v]

There could be a host of human error reasons for this.

 

[Guillermo]

There could be a host of human error reasons for this

considering what is going on at S&W...you certainly are right.