PDA

View Full Version : MIM Parts


IdahoG36
September 11, 2007, 05:28 PM
Why do so many people say that MIM parts are junk and they wouldn't want them in their guns? MIM parts are used in the aerospace industry, surely they are good enough for firearms. All of the major manufacturers use them in their guns anymore, except the truely high end custom makers. I just notice that quite a few people on this forum object to MIM parts. I have read that MIM parts are just as good as machined parts, as far a strength goes, and it is easier for a manufacturer to mass produce small, complex pieces.

Jammer Six
September 11, 2007, 05:37 PM
Not sure the aerospace industry reference works in your favor. They seem to have, shall we say, a spotty record, and a reputation for cutting corners.

Not to mention that there aren't very many gunfights in space...

steveno
September 11, 2007, 06:14 PM
here we go again

HappyGunner
September 11, 2007, 06:16 PM
There are many MIM parts that have worked for years in many handguns.;)

Alnamvet
September 11, 2007, 06:27 PM
cast....who cares? With proper heat treating, every bit as strong and reliable as forged....sheeessshhh.

IdahoG36
September 11, 2007, 06:28 PM
I created this thread because I see people on this forum say that MIM parts are junk, or that they wouldn't trust them. In reality, almost all firearms manufacturers use them, so they can't be that bad. I am just curious as to why people say that they are inferior.

Alnamvet
September 11, 2007, 06:30 PM
...the only folk who talk bad about MIM parts are Colt fanatics whose sole arguement as to why the Colt 1911 is better than any other makers 1911 is that it uses less MIM parts...big deal.

Jammer Six
September 11, 2007, 07:18 PM
There are many MIM parts that have worked for years in many handguns.
There are many people who drive drunk without having accidents.
...the only folk who talk bad about MIM parts are Colt fanatics whose sole arguement as to why the Colt 1911 is better than any other makers 1911 is that it uses less MIM parts...big deal.
Not even close.

Don't own a Colt. Don't like MIM.

Sweeping generalizations are a sign of intellectual laziness.

RJay
September 11, 2007, 07:29 PM
When I read some of the posts in reference to the weakness of MIM parts, I just smile to myself about somebody trying to act knowledgeable in spite of the lack of knowledge and just keep on trucking.

Shane Tuttle
September 11, 2007, 07:46 PM
Not sure the aerospace industry reference works in your favor. They seem to have, shall we say, a spotty record, and a reputation for cutting corners.

REALLY, Jammer Six? Care to clarify before I refute your statement without content?

I don't care what parts are made for my gun as long as it's reliable. MIM or forged, they have their places...

Jammer Six
September 11, 2007, 08:15 PM
Gee, stud, no need.

You've convinced me. It must be your style, class, and concise, cogent arguments.

{snicker}

awpk03s
September 11, 2007, 08:46 PM
A common argument, not limited to firearms. In my industry we utilize several components made of heat treated powdered metal. Is it as strong as a forged steel part or a machined steel part? Maybe not. But the point is it's strong enough for the purpose it serves in our product - so who gives a [color=#FF0000]█[/color][color=#FF0000]█[/color][color=#FF0000]█[/color][color=#FF0000]█[/color][color=#FF0000]█[/color] if it's not steel? Steel for those components and purposes does nothing more than increase cost.

Same logic I believe applies to firearms. "But wait, that gun's frame is plastic, it can't be as good as steel or aluminum alloy!".

kristop64089
September 11, 2007, 09:10 PM
Maybe, if you despise MIM parts, you could explain why & share your personnal experiences with MIM parts failure.

I asked my father (tool and die maker) what is wrong w/MIM. He could not say anything bad to it, other than the already stated, It speeds the production process up.

I have a gun that I am sure is chocked full of MIM parts. It is accurate as hell, and round count has to be close to 10,000. NO failures to date.

Maybe I got a lemon?

Jammer Six
September 11, 2007, 09:11 PM
so who gives a [color=#FF0000]█[/color][color=#FF0000]█[/color][color=#FF0000]█[/color][color=#FF0000]█[/color][color=#FF0000]█[/color] if it's not steel?
You must mean besides me, a bunch of know-nothing 'smiths, and the line forming around the block...

Ocraknife
September 11, 2007, 09:27 PM
Sweeping generalizations are a sign of intellectual laziness.

Didn't you just make a sweeping generalization about people who make sweeping generalizations?:confused::D

dwatts47
September 11, 2007, 09:39 PM
Lets take this to automobiles to shed a little common sense light.

Nascar: 800+ horse power, 7700-8900 rpm avg, 500 miles... car must last, engine must continue to make max power.

Do we think dale Jr's car has cast, low cost pistons and crank in the block... like your last ford taurus, or maybe does it have stronger FORGED pistons and crank for durability...??? Got your answer yet?

do we need more time to think about this one?

MIM=cast
cast=lowcost or more importantly, lacking in strength.

Shane Tuttle
September 11, 2007, 09:51 PM
Gee, stud, no need.

You've convinced me. It must be your style, class, and concise, cogent arguments.

I see that you, again, made an accusation without backing it with content.
1. I'm not a horse nor a "cool dude that is God's gift to all women".
2. I am a decent speller, so I'll presume you mean an intellectual debate. With that, I'm not in the position to state my opinion without first hearing what your reasoning why the aerospace industry doesn't earn your audience. Therefore, there is no engaged argument...yet. All I stated is for you to back up your claim. Otherwise, maybe I should take your empty statement at its face value...

do we need more time to think about this one?

MIM=cast
cast=lowcost or more importantly, lacking in strength.

Nope. There are plenty of testimonials that claim their firearms work without hiccups for thousands of rounds using MIM parts.

Look at old WWII Lugers. See any forged parts in there? What about Colts from the same era? Lots of these guns would still fire today. Off topic of handguns, I have a milsurp rifle dated 1916 and it hasn't let me down. As a matter of fact, it's more accurate than most production rifles made today at the same approximate value. My question is a serious one. Don't really know if forging parts were made in these guns back then, but my money is they didn't due to mass production needs at the time...

Ocraknife
September 11, 2007, 09:52 PM
MIM=cast
cast=lowcost or more importantly, lacking in strength.

Now you have me curious, I am interested in metalurgy, exactly how much weeker is MIM than a forged part? How much strength is needed in a given firearm and by extension how much strength is lacking. Please cite your sources as well.

Jammer Six
September 11, 2007, 10:11 PM
Yup, I did.

I'm lazy where the intellectually lazy are concerned.

And you caught it, not my target. :D

Otherwise, maybe I should take your empty statement at its face value...
That's exactly what you should do.

Buh-bye!

dwatts47
September 11, 2007, 10:17 PM
Well first Ocraknife, You're not my teacher and I'm not your student. Do your own report and sight your own sources, if you have that much interest.

But since you need to have this proven to you, here goes.

A Forged knife blade is what? A piece of steel, heated and pressurized, to make the molecules more dense. Then heated and pressurized, and again and again and again, until a desired hardness is reached. Japanese swords forged by blacksmiths were known to have been heated, folded and pressurized (read hammered) more than 200 times. Why? strength.

A cast anything is what? A mold, with a heated matter poured into it for shape and then cooled until desired shape is reached. Mold is broken, cast thing is finished. In this case, the hardness is acheived by speed at which matter is cooled and original mixture of said matter. Since the mold must form the matter, the mold must be stronger than that which takes shape inside it. Otherwise the mold and the item would simply become a 2 layer "filled" mold. This is much the way candles are made.

Metal injection molding is a split between the two. Molten metal is injected in a you guessed it, stronger than it is mold, pressed and heated (quickly) then separted to release 'finished' part. This is much the way Barbie dolls are made.

Now, do you want gun parts made like a 19th century japanese sword, made like a candle, or made like a barbie doll? I have no way to know by what percentage a forged part is stronger than either of the other two. Aren't the names of these parts enough to let you decide which one you want in your save you behind tool?

The Tourist
September 11, 2007, 10:24 PM
Rugers are made with a modern rendition of 'sand cast' or what used to becalled "lost wax" tecniques.

And I can remember when you could pound a Redhawk a lot harder than an SW 629.

Jammer Six
September 11, 2007, 10:53 PM
Actually, no one is above being asked for a citation.

Not supreme court justices, not scientists, not doctors.

If it's just your opinion, that's fine, but it always looks better if you just come out and admit it rather than trying to pass your opinion off as fact.

Stating your opinion as fact just looks uneducated.

As it happens, we agree on this issue.

Have a nice day!

dwatts47
September 11, 2007, 11:01 PM
Guess you got a point there Jammer six, ;):D

Jammer Six
September 11, 2007, 11:08 PM
Do you have a cite for that?

Oh, wait... :confused:

RsqVet
September 12, 2007, 12:15 AM
MIM parts can and do fail, that has been observed, could be a design flaw or manufacturing flaw...

A MIM part that replaces a part designed to be made from forged or machined steel such as 1911 parts raises the issue of if the new material is sufficient or superior to the old... the high end 1911 croud obviously has a stong view of this... for my money as well I'll go with the non-MIM parts from a guy like Baer or Brown... if the question was forged parts from off shore or the Wilson MIM parts I'd really have to think on it. .

On a gun designed with MIM in mind it might be a totaly diffirent thing.

On parts made by a company with good quality controll it might not matter either... most failed parts I have seen in guns (and I'm not a gunsmith) look as though they were flawed in the making or progressivly failed... I'm guessing this is the case with most reports of failed MIM parts.... and has been seen with forged parts as well.

Keep in mind as well when we talk about aerospace... all those MIM parts are made with a heck of a lot more quality control, and likely magna-fluxed, x-rayed or subject to dye penetrant testing if they are at all critical parts, testing, which they would have to be subject to no matter what process they were made by and MIM is cheap enough so that even if one in 20 fails, if each part is 1/8 the cost of a part made by another process who cares?

Jim Watson
September 12, 2007, 07:26 AM
Maybe I shouldn't get into this one but stuff like the following needs help.

Japanese swords forged by blacksmiths were known to have been heated, folded and pressurized (read hammered) more than 200 times. Why? strength.

My local martial artist says the historical scrap rate for new samurai swords was about 50%. Breakage upon whacking an enemy was high. He has a real signed period blade with a flaw that might well make it a "single shot."

Since the mold must form the matter, the mold must be stronger than that which takes shape inside it.

A casting mold must only be strong enough to hold the weight of the molten metal. Ruger uses a ceramic dip that is chipped off the part. A jeweler uses a high temperature plaster.

Metal injection molding is a split between the two. Molten metal is injected

At no time is the metal in the MIM process molten, it starts as a very fine powder in a soft plastic carrier that is injected into the mold. It then has to be heated to debinderize then heated more to fuse the metal particles, then heated again and quenched to heat treat. Part shrinkage through all that is 20-30%. If you don't figure the shrinkage right when sinking the molds, you can have nice smooth parts that don't fit. One name brand sent out a bunch of pistols that would not slide lock when empty. I suspect they got the mold for the complicated slide stop shape a little wrong and were reluctant to spend the money to replace it until the customer complaints built up.

I consider good MIM to be a satisfactory method. But we seldom get good MIM in guns, we get cheap MIM. The cost of molds and metal goo being what it is; good MIM would likely cost as much as milled. MIM will have "arrived" when something still cheaper comes along and you find yourselves requesting and paying extra for "good old fashioned MIM" parts.

Firearms MIM sure doesn't get the kind of quality control described for aerospace, either. (Very few guns get that kind of quality control. The Springfield Pro, built to FBI specs, cost about $500 more than its description would warrant, except that the FBI requires magnafluxing.)

HappyGunner
September 12, 2007, 09:06 AM
I don't feel by just requiring magnafluxing the FBI are really getting more then just finding surface flaws.:rolleyes:

Hunter Customs
September 12, 2007, 09:39 AM
Mim parts serves two purposes, it allows gun manufactures to mass produce guns at less cost (build them cheaper not better); it keeps gunsmiths in business replacing failed parts.

When it comes to the 1911 pattern pistol it used to be parts were changed to reduce tolerances and give a gun a custom look, not because of part failure (one exception to this was the Colt collet barrel bushing), then along came MIM parts.
When I'm talking part failure I'm not talking parts that wear out from use I'm talking parts that break.

I've seen MIM barrel bushings split and some with the lugs sheared off, hammers with the hooks sheared off, sears that split both in length and across, plunger tubes with the studs sheared off, hammer struts break, safety lock pins break, slide stops with the pins sheared off or broke in the center and firing pin plates break into two pieces.

It's pretty hard to convince me that MIM parts are as good as or better then top shelf cast or forged parts.

Regards
Bob Hunter
www.huntercustoms.com

HappyGunner
September 12, 2007, 11:49 AM
It matters little what people think about MIM parts being used in many firearms they are here to stay.:rolleyes:

With most of the MIM part failure I have read about for the most part they will happen quickly.:)

Jammer Six
September 12, 2007, 12:10 PM
I guess it depends on what you mean by "quickly".

I had a MIM thumb safety break in half after about 10K rounds, a sear split after about 30K rounds, and a thumb safety break after just a few hundred rounds.

Socrates
September 12, 2007, 12:54 PM
Two groups of people on MIM parts:

Those that have had them break quickly, or in bad situations,
and those that haven't.

It's sort of how most people become Republican:

A Democrat that's been mugged, or lost more then half their income in illegal taxes.


S

Esq.

Jammer Six
September 12, 2007, 02:30 PM
Nope, nope, nope.

There are three kinds of people: those who divide people into two group, and those who are good at math.

Alnamvet
September 12, 2007, 02:36 PM
3 people....one is a troll, and the other 2 are not able to see what the troll is doing...is that like divide and conquer?