MIM Parts Question.

Yes, but also, manufacturers don't have to invest in the MIM equipment. Just buy the parts from somebody that has. This from my rarlier posted link.
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Exactly. They spec the part they put it out to bid and award a contract. Not every process is brought in house.

Look at Pine Tree Castings, which is owned by Ruger, makes cast gun parts for tons of other companies.

http://www.ruger.com/casting/

When done right MIM is a solid way to manufacture a part. The same can be said of any manufacturing process. ;) There are good forgings and poor forgings. There are good castings and bad casting processes. There is good MIM and bad MIM.

The problem is when you get it wrong with MIM you get this ... http://thefiringline.com/forums/showthread.php?t=526661

broken_sight.jpg
 
If a modern F-150 was made the same way as a Model T, there would be a lot more jobs.. but nobody would have cars because nobody could possibly afford them.
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Foolish statement of the day award.

Henry Ford was the first of his time to pay his people well enough so that the people who manufactured his products could actually buy them...

That almost set off a firestorm in American industry. He was called every name in the book (start with "heretic" and go from there) by his manufacturing brethren. He was the devil incarnate. He was the one who would ruin profits for all manufacturing companies.

Guess what? Didn't work out that way, and US companies thrived for many years thereafter.

Just as MIM is not the Devil's work...although it is frequently made out to be.

Next time you are flying on any US airliner, look out the window at the engines that are lifting you and holding you aloft. Hundreds of compressor and turbine blades, each moving at many thousand rpm and under unimaginable g forces (and heat, in the turbine blades) are surviving for thousands of hours in brutal conditions.

And they are MIM parts.

Sleep well.
 
If a modern F-150 was made the same way as a Model T, there would be a lot more jobs.. but nobody would have cars because nobody could possibly afford them.
Foolish statement of the day award.
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I do not agree. I think that the reference was to the fact that the technology of Henry Ford's time, although advanced, and innovative at the time, is outdated today. That F-150 referred to is built on an assembly line with many robots replacing hourly wage earning workers. Right or wrong, it is 21st century methods, and does effect cost, and price.
MIM is also 21st century technology, and as pointed out works well for the purpose, and helps to control cost.
 
Buck460XVR said:
Actually the investment in the machinery and the cost of materials to make MIM parts makes them much more expensive than similar forged or stamped parts.
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In a nutshell, this is incorrect. MIM parts come out of the oven ready to go, at the final dimension. A forged part cannot be forged true to a final dimension, it gets pounded into an approximate shape and size and then requires machining. Machining is an additional step, requiring one or more additional operations, machines, and operators.

Further, forging is not an appropriate technique for making small parts such as hammers, sears, etc. Those types of parts, if not made by MIM, are typically machined from bar stock ("tool steel").

There's a reason why Wilson Combat's MIM line of hammers(to use one example) sells for half what their tool steel hammers cost. Externally, they look identical.
 
One difference with machined from stock parts is the expense of cutting heads and the waste of metal removed. Aside from the costs mim parts are basically cast using a powdered metal and bonding agent mixture which as was mentioned earlier is plengy strong for those parts I a gun where as powdered metal connecting rods is a different process that uses pressure to forge the powder into a high density solid resulting in a part with the strength of a forged part with less internal stress. The problem with connecting rods is not making a part that is strong enough, those have been around for years but with making a part that is strong and has fewer internal and external stress points.
I think the process used in rods would be perfect for firearm frames, slides and even barrels and would result in even stronger guns then we have now. The problem I think would be that guns require a fine level of finish that rods and the like do not. This extra step would require the forged part to be machined and finished. No one wants a handgun with the finish of a connecting rod.
 
I think the process used in rods would be perfect for firearm frames, slides and even barrels and would result in even stronger guns then we have now. The problem I think would be that guns require a fine level of finish that rods and the like do not. This extra step would require the forged part to be machined and finished. No one wants a handgun with the finish of a connecting rod.
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I visited Valenite in Saline Michigan. They make indexable carbide cutters using powdered metal (carbide) and wax in "pill presses" The only difference between MIM and their method is how the powdered metal/wax gets into the form. After being pressed, the green inserts are fired in a furnace to melt off the wax and fuse the carbide inserts. My point is, the finish on the completed objects is as smooth as most machined surfaces.
Therefore, I do not think surface finish of a MIM gun frame would be problematic. But, MIM is usually the realm of small objects, Investment Casting usually is the realm of larger objects. However, Bill Ruger Jr. stated some years before he died and that eventually Ruger would be making rifle barrels via investment casting, with the rifling in them. The finish of such objects (MIM and Investment Cast), are not as is objects made via sand casting. Furthermore, an MIM or Investment Cast Automatic frame generally only needs machine finishing where the slide rails contact it. Also, Ruger Revolver frames are investment cast and then polished, so surface finish is not a problem.
 
I had two MIM hammers wear out in my Clackamus Kimber. Kimber replaced the second hammer for free, but the trigger pull was awful, I took the pistol to Camp Perry to have the Marines do a trigger job. They told me the MIM sear was worn to an irregular shape and it could not be adjusted. Their advice was to go over to the Springfield Armory building and buy a forged sear, which I did, and they tuned it to perfection.

So far the forged sear and MIM hammer is holding up but I think the contact pressures on sear surface/hammer notch are too high for the MIM parts Kimber uses.


If this next MIM hammer goes, I am replacing it with a forged or machined barstock piece.
 
Dahermit, that process for making bits yields a "hard" part but rods and sonething like a gun part would likely require something with more tensile strength and less hardness. Strong and hard are not the same. Hard parts like to break when stressed. Rods also get an additional forging step after sintering which gives them the strength they require.
 
Dahermit, that process for making bits yields a "hard" part but rods and sonething like a gun part would likely require something with more tensile strength and less hardness. Strong and hard are not the same. Hard parts like to break when stressed. Rods also get an additional forging step after sintering which gives them the strength they require.
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EnoughGUN, You seem to have a poor understand what "Powder Metallurgy" is. The carbide cutting bits I watched being made (as part of my Master's degree), were a mixture of Tungsten, Steel, Carbon and wax (for a temporary binder, is baked out). To make a part suitable for use in a firearm, one would use powdered metals appropriate for its intended use (4140 perhaps). Hardness, brittleness are not an unavoidable by-product of the powdered metal processes. Brittleness, as in the recent Ruger sc1911 front sights breaking, is most likely caused by incorrect drawing of the part after the part has be heated to fuse the metal(s), and melt out the binder. The finished parts for a gun (using correct steels), would be heat treated (hardened and drawn) to achieve specific properties. Nevertheless, connecting rods are more likely to be investment cast, not MIM.
An interesting side note, Valinite not only made Tungsten based bits and Titanium Nitride (a Ceramic) coated bits, they made homogeneous (100% Ceramic), Titanium Nitride bits.
 
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Enoughgun:

"Dahermit, that process for making bits yields a "hard" part but rods and sonething like a gun part would likely require something with more tensile strength and less hardness."

Well, there now, you really stepped in it with this belief that among metal-based machines, guns are somehow da most speshul and da most demanding on their metals.

OIW, I beg to differ most vigorously. A connecting rod attached to a crank going even a middling 5,000 RPM I'm SURE requires more *tensile* strength than any current-production MIM gun part.

Same for compressive strength.

Over a duty cycle exceeding the life of any firearm I can think of, in about an hour's operation.

Not springs, not barrels or the stressed parts of receivers and slides.

I do not know how to compare the transient stresses of the firing cycle on those specific parts, to the cyclical and longer-duration stresses on connecting rods.

But I do know that if any metal part under high stress is likely to break when those stresses are loaded across an area with a sharp-cornered inside radius. Somebody smarter than I am can even calculate the crack-resistance differences between a .002 radius and a .008 radius.
 
Yes, i understand the metallurgy behind the process and that a different mixture of components would change the properties of the part.



"I visited Valenite in Saline Michigan. They make index able carbide cutters using powdered metal (carbide) and wax in "pill presses" The only difference between MIM and their method is how the powdered metal/wax gets into the form"

You mentioned nothing about another difference being the difference in the actual composition of what you put in the form... I would say that is a pretty important point. I mentioned that the bit would be hard but not particularly strong as far as what a gun part needed because that was the entire point of the original conversation about using a process like that used in rods and your statement suggested you did not consider it or understand that difference in the two processes Masters degree or no.



"Nevertheless, connecting rods are more likely to be investment cast, not MIM"



Actually neither, Rods (as far as what was discussed previously in this thread) are powder forged. The process is similar to MIM but after they are heat treated the part is forged in a die to their finished shape but usually require some machining. Another point your post suggests you missed was that concerning cost strength and additional finishing work I was comparing machining and the MIM process to that used to make high performance auto rods not another product using the same process that MIM gun parts use. My point being that you could just machine a part from billet in one process with maybe some polishing to finish it or you could (if you used the same process as rods) powder forge one and have a stronger then MIM but you would be adding a machining process and polishing anyway if you were looking for a refined product. The machining is probably more expensive over all is cutting steel because of the waste, expence of cutting heads and time to produce the more complex parts but is less steps while the powder forging may be less expensive but an extra step may offset the savings over the both cheaper and less complex MIM process. This is just me guessing of course. Maybe someone with more actual real world production experience with these process can weigh in.


Grump I believe you did not read what i wrote correctly. I know a rod is under vastly more load then a gun part as if you read back in the thread I mention.

"I believe the powdered rods for engines you are talking about use a different process. Powered metal is forged in a die under insane pressure, enough to basically make it a solid part. The result is a part that has the density of a forged rod but none of the internal stress points you can get by beating a solid block into shape. Be it as it may I still think that most of the mim parts in a gun have the needed strength. The strength required in a high performance connecting rod makes the stress inside a firearm look like kittens playing tug of war "The quote you are referring to was in comparison to the BIT as in cutting bit that dahermit was talking about a gun part needs to be less hard but stronger.

"I visited Valenite in Saline Michigan. They make indexable carbide cutters using powdered metal (carbide) and wax in "pill presses" The only difference between MIM and their method is how the powdered metal/wax gets into the form"
 
...Powered metal is forged in a die under insane pressure...
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That is probably what threw me...I was expecting P.S.I. I guess I will have to go back to college and learn about units of "insane" pressure. :D
 
What? Thats not an industry standard term? I believe its something like 400 "gobbs" per insane if I remember my community college correctly.

Actually I had it wrong, the forging step is after the heat treating not part of it.
 
In this day of plastic, pot metal and aluminum being used to build guns why is anyone worried about MIM parts? I seem to find fault with most of the new guns I buy but so far none of the problems are because of MIM parts.
 
pete2 said:
In this day of plastic, pot metal and aluminum being used to build guns why is anyone worried about MIM parts? I seem to find fault with most of the new guns I buy but so far none of the problems are because of MIM parts.
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It seems like MIN parts properly made are our friend. Being that they are precision made , close tolerance, high strength parts at bargain pricing. Until I have a problem with them, I'm not going to worry about them.
 
I am a firm believer in modern technologues, but jet turbine blades are NOT MIM. They are basically grown from nickel alloys (metals have a crystalline structure). MIM parts on a handgun should be just fine.
 
I will grant that MIM is not by definition bad; however there are far more details to consider than a simple good / bad vote.

1. First is company making the MIM part a quality company, with a good process and good quality control??? Think about it, how many people here have broken a "forged" in china tool? I have plenty of times, forged, machined from billet, mim or whatever matters not if the company doing the work has no attention to detail and quality. If one sees may poor / busted / broken MIM parts from a given place this would suggest that they do not do such a good job.

2. Is the part designed / suitable for MIM --- more than one gun part has had to be re-designed in some way to be made from the MIM process, if one neglects that than more than likely nothing good will come of it.

3. What is the price point of the gun in question? MIM is adequate in many applications so for a service grade / price weapon if all other details are attended to then there is not much to get upset about with regard to MIM.

If on the other hand one is looking at top tier / premium guns where every last detail and element of quality is expected to be present / addressed then the market largely rejects MIM for the slight edges that other processes have. Most of the conflict over MIM has arouse from the middle to upper end market -- no one is complaining or expecting a 700 dollar price point 1911 to NOT have cast or mim parts, to expect otherwise would be just dumb. Conversely Wilson Combat stopped using MIM in their "lower end" guns because the market forces simply demanded it even though Wilson MIM parts were considered excellent. Likewise in the higher end 1911 range, say 1400 plus companies that use any MIM parts are frequently ridiculed, given that one can find guns in this price range with no mim parts.
 
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