MIM Innovation Or Cheap Plastic

Status
Not open for further replies.
V

Vermonter

New member
I have read here and elsewhere a number of opinions regarding the use of MIM technology in firearms manufacturing. It comes up mostly in the handgun threads therefore I am posting it in General Handgun. Mods if you would prefer it somewhere else please feel free.

To me it is a process that seems solve economical problems for manufactures. I am all for that especially if savings are forwarded on to consumers.

I read this to develop a better understanding of the process..........

http://www.ssisintered.com/MIM_index.html

What I am looking for here is specific gripes with what was proven to be a failure of MIM technology. I would like to develop a list of firearms and parts that seem to have failed due to MIM parts.

With Kindest Regards, Vermotner
 
"WAS proven" ?? When MIM started to be used for firearms it was a new technology .Therefore it had to be improved, proper applications had to found , improper applications discarded .This is typical of any new technology !
What are you trying to do , write a history of MIM in firearms ? That would be the only proper reason to deal with the "was proven" . If not , let it rest !
 
What I am trying to do

I am attempting to do two things.

1. Learn for the good of knowledge.
2. Figure out which used (or for that matter new) firearms to avoid.

Proven admittedly may not have been the best choice of phrase. Perhaps which MIM firearms were known to have problems. I am aware that S&W revolvers are known for issues with this however what else am I missing?

Thanks, Vermonter
 
I'll play. :)

S&W 4516-3. MIM mag catch snapped during an IDPA match, like the cheap pot metal it was. Replaced it with a forged mag catch from a 4566. No more problems.

Kimber Stainless Target II 45. LH thumb safety snapped off. Gunsmith replaced with a forged thumb safety. No more problems to date.

Thats it for me, so far. ;) In my revolvers I go out of my way to avoid MIM. To me it is a cost cutting measure, nothing more. Good luck with your research! Regards 18DAI
 
18 Dai

Those are the specific examples I am looking for. So the sqme part MIM vs non MIM and the forged part preform better.
 
Although I have not studied any failures of MIM parts, I tend to think many of the failures could be due to improper sintering temperature rather than compaction.
 
My understanding is the failures aren't caused by the part being made from MIM but rather the part was improperly made to begin with.
That said, MIM is nothing more than a cost cutting measure but how much does it really save... $50 per gun? a hundred?

Jim
 
I don't deal with MIM, but at my job I am a frequent user of PM and sintered gear components, and I can't help but notice the failures noticed I have witnessed directly with some of our gears. Exactly as tekarra said- the integrity of the part is directly related to heat treat. For example:

At my facility, we are using powdered metal gears, and they were failing at half the load (or less) of what we expected them to. Spec was 45-50 Rockwell C. The gears that broke were around 30 Rc (so pretty dang close, but not exactly). We could take the same lot of gears that were in spec and their load strength was triple that of the "softer" gears. Also, upon failure they give the appearance of a density failure (the "pot metal" appearance someone mentioned), so it's almost counter-intuitive to think heat treatment is at fault. Hardness is a HUGE factor in the effectiveness of the metal to retain its composure. Don't get me wrong, I'm all about forged materials and how bombproof they are, but the process itself isn't at fault. Just like anything else, it has to be done properly to be effective.
 
The first MK III Colt Troopers had sintered metal parts. They did call it mim in those days. I was told there were a lot of failures.
 
'Sintered' is the process of heating to bond the particles together .It is used in powdered metal and MIM.
Sintered parts can be heat treated and case hardened too !
Remington has made PM parts 40 years ago [I saw their process] and specialized in high strength parts approaching wrought .It required double compacting and sintering ! They are involved now with MIM.
There are gun applications that are not appropriate for MIM ,they should have asked me !! :p
Metallurgy rules !
 
As always, it's the poorly made parts that break, no matter what the manufacturing process is, MIM or machine cut. I guess they don't put poorly made MIM parts in airplanes and race cars, because they do use some MIM parts.

It's always seemed (from internet reports) like the MIM gun parts break early on in the life of a new gun.
 
I'll take forged parts any day over MIM. The good thing is, you can usually find good forged parts to replace the MIM parts, on popular firearms.
 
Im still trying to find out what the "cheap plastic" part of the thread title is referring to.
Click to expand...
It's another silly (and utterly incorrect) aspersion some folks use to refer to MIM.

Despite numerous secondhand accounts, I've yet to see failures of MIM parts solely due to the method of fabrication.
 
if the design of the part doesn't lend itself to MIM and yet MIM is chosen, that's an engineering flaw, not a MIM problem

I'll take forged parts any day over MIM. The good thing is, you can usually find good forged parts to replace the MIM parts, on popular firearms.
Click to expand...

Forgings are not the end all and be all for design :) I can name a firearm part that is cheaper to make, less time consuming to make, easier to make, and more durable when it's not made of forged steel but is instead made of a cheap steel stamping; and that's exactly why the slide cover on the P.38 is a stamped part: for that application, forgings suck. At one time, stampings were derided and scoffed at
 
Last edited:
Like everything else there is good MIM and bad MIM. The process itself is not bad it is the application and use of MIM parts for the wrong applications that is the problem. The other problem is that some companies will develop a good MIM part and then over time cheapen it to the point of failure.

My main issue with MIM is that it exists not to improve any given firearm but instead is there to make it cheaper to produce. Their use in the firearms world is born out of cost cutting and the "good enough" for most people manufacturing mentality. As companies look to squeeze that last $.01 of profit the quality of all parts not just MIM too often gets compromised. IMHO

Parts that are often MIM are things lik:

hammer
sear
disconnector (1911)
firing pin stop
grip safety
thumb safety (1911)
slide stop
front sight
rear sight
plunger tube (1911)
mag release
ejector
extractors
 
Status
Not open for further replies.
Back
Top