Mim?

[Tunaboat]

Can some please explain what MIM is?

thanks

[1911Tuner]

Metal, Injection Molded.

[Hunter]

This link may help.http://www.azom.com/details.asp?ArticleID=742

[wichaka]

Metal, Injection Molded.



Nasty stuff......... :scared: :nono:

[pa_guns]

Hi

Makes great knives and forks. Walmart sells a lot of them. :D

When it comes to high end stuff like pistol parts you need to pay a lot of attention to the details on MIM. Not everybody does. Best to avoid it if you can.

Bob

[Tunaboat]

What manufactures use MIM? And specifically what parts?

[wichaka]

Most all the small parts on the 1911 anymore are MIM........Colt is the only company that still uses solid steel for most of their small parts. They still have some MIM, just not near as much as others. Thats why you see them a bit higher in price.

[John]

Again, do not blame the process, blame the manufacturer for not following quality standards either constantly or while producing a particular batch. MIM can produce fine parts, as long as it is done right. I wouldn't advise using them for any part which receives stress, but for parts like grip safeties, thumb safeties, sights there is no reason for not accepting a MIM part.

[1911Tuner]

MIM's quality and durability depends greatly on the care in execution of the process and the material used. There's good MIM and there's bad MIM. I've seen some that's every bit as good as high-grade machined steel...and I've seen some fall apart at the least provocation.

The problem is, that you can't tell if it's good until you put the pressure on. The other problem is that some parts aren't well-suited to MIM, no matter
how good the quality is. Sears and disconnects...generally okay. Hammers and barrel bushings...much less so. Impact and repeated shear stress seem to be the flies in the ointment, although I've tested a Colt sear by hitting it hard with a hammer on an anvil...and it held up nearly as well as good machined steel.

As a rule, if it's bad, it'll fail early on. If an MIM sear lasts for a thousand rounds, chances are that it'll last for 50,000. Colt seems to have tied in with a vendor that produces consistently good MIM. Other manufacturers have been hit and miss...which suggests that Colt has stuck with one, while some of the others are constantly searching for the lowest bidder. Colt also seems to understand that some parts just aren't suitable for MIM. Their hammers, and struts, for instance...are blanked, finish-machined steel.

[Kruzr]

A good tutorial on MIM: http://www.megamet.com/tutf.htm

The "defects" section is enlightening for those who don't understand why MIM can be as strong as forged steel or as weak as pot metal. The only quality control that works is radiography. GE uses MIM for the inlet nozzles on gas turbines and aircraft engines. These are the stationary foils that guide the air into the rotating foils on the rotor. They X-ray each part but they can afford to. A gunmaker can't.

I was recently surprised to learn that the SA Pro used by the FBI HRT uses a MIM slide stop. Seems like a high stress part to me. I don't have much problem with MIM other than it doesn't belong on a gun costing over 2 grand.

Our last Kimber range rental went a little over 90,000 rounds before the MIM sear gave out and the gun went full auto. We were never able to get that life out of any other 1911 for a rental. Prior to the Kimbers we had 2 Colt NRM's and 2 SA's, a Mil-Spec and a Loaded.

As Tuner mentioned, when MIM breaks, it almost always goes early in it's life. You can see why in the defects part of the tutorial.