MIM Parts not durable?

[robot]

I've read in many places about the durability of MIM (Metal Injection Molding) parts from multiple forums.

has there been a study done that proves this point using scientific methods? similar to the many ballistic reports of bullet performance that numerous people have done.

thanks!

[Cannibul]

Anything can break.

MIM parts tend to break very quickly under use if they are prone to failure.

[SRD]

MIM if made properly can be very strong, but there seems to be a higher failure rate of MIM parts but normaly it really is just fine.

[misfit-x]

It's just like anything else, quality will be quality and cheapo will be cheapo. If you have a "budget" gun the MIM probably won't be the best but if you have a quality firearm you should be fine.

[MagicPie]

A properly done MIM part is near the same strength of one that is machined. The problems of MIM as mention all come from poorly done processes, but not so much because of the process of MIM.

Like many things on the internet, it's blown out of proportion. Typically this comes from overblown hatred of Kimber, to whom uses MIM. Sharing the same "it sucks" talk with no evidence to support it, as exampled in the Kimber thread here.

[bel970]

haven't seen any scientific studies but it pretty much comes down to that MIM parts are pretty much the same thing as cast parts, solid billet can bend and flex cast and mim fractures and breaks, partialy do to the density of the material and how the molecules line up. but there is a huge differance in price, MIM parts are cast with little to no waste and need little to no machine work, parts from billet can have a huge waste factor and must be machined not to mention the cost of the billet in the first place.

if properly designed and used in the right application they aren't an issue (SA XD for example) if done incorrectly they are a massive problem (jennings).

[jimi4444]

Mim
Metal Injection Molding aka MIM

Outlined here

Basically it uses 60%ish metal and 40%ish binding material and injects it into a mold to produce what it needs. Just by seeing the percentages you can guess that it is below a full casting. The reasons they are used is largely due to taking away cost of machining as mim parts rarely need any major machining after saving on waste and machining time/effort.

Included Problems with MIM is when you use cheap metal it brings out the weak aspects of the metal. Along with air pockets forming or bonding materials not working correctly. Likewise the properties of MIM parts are that it will shatter/crack while a full metal will bend more before it breaks. These are general problems and can do research on your own as I am no where near an expert on MIM. Or another can fill in the blanks that I do not know.

Re posted from another post.

MIM parts will not usually be as durable as a cast or a full mold, but on the other hand some parts are not needed to be cast. There are plenty that will say guns with no MIM parts are a must for true reliability. Although it is good to have no MIM parts it is not always needed.

I liken this to a car. The floor boards that you sit on are just tack welded (one small weld think of it as a small bead of metal) every few inches to hold your seat and everything inside from being dragged underneath the car, as opposed to welding it fully as you would see in high-rise metal beams. No one even considers ever having the floor boards drop out and their seat and everything falling under a car while you are driving. Why? because the tack welds are plenty strong enough to hold whatever the car can handle.

But on the other hand you want a full forged or cast in your pistons (the things that handle the brunt force of the explosions in your engine). Why? Because it takes force that a MIM or pieced metal could not handle due to the force.

Moral of the horrible story, sorry I am dead tired. MIM parts if properly manufactured can more than handle what is needed in the parts that due not take brunt force, just like the tack welds, and shouldn't be worried about. MIM parts that do take brunt force, if made properly, can still be reliable and trusted, but are pushed to their limits more than most cast parts. For an analogy:

You are going out to move 1,800 lbs of gravel 10 hours away and you have a choice between 2 trucks to rent. Truck A has a load rating of 2,000 lbs. Truck B has a load capacity of 2,500 lbs, but cost $50 more per hour. Which would you choose? Both can do the job, but one gives more leeway for if you hit bumps or something else gets thrown in or you ride it hard or normal wear and tear that makes the load capacity drop slightly. The other costs considerably less but never-the-less can get the job done. This would simulate parts that take the brunt force.

Now take the same scenario above but instead of 1,800 lbs of gravel you are only hauling 500 lbs. Would you feel safer with truck A now? This would simulate the MIM parts that do not take brunt force.

Same concept here. Both can do the job, but non-MIM parts gives more leeway and piece of mind than MIM parts. The choice is if you want to pay the premium for the extra leeway and piece of mind.

Side note, even some higher end guns $1500+ use MIM parts on the parts that don't take brunt force.

Hopefully I didn't confuse you too much.

[ranburr]

With quality 1911 parts available in abundance, there is no reason to waste time with MIM.

[fireblast713]

I don't like the idea of MIM parts... however I have yet to have any failures due to them, I still might replace them anyways

[bigun]

Originally Posted by Cannibul

Anything can break.

MIM parts tend to break very quickly under use if they are prone to failure.

False MIM is as strong as cast and sometimes forged steel the caveat is that it must be done properly. A Lot of the problems with MIM have to do with voids and improperly hardened parts. Even forged steel parts break. My last Kimber Custom Target 2 had in excess of 30,000 rds through it without a broken part, My old Colt 1991 was the same neither showed appreciable wear on the moving parts. My Para Ord LDA CCW however was the example of poor quality MIM, The slide stop bent, x-tractor broke, magazine release broke all in the first 1500 rds.