You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
MEM vs Forged parts
- Thread starter Coop57
- Start date
Actually it is MIM. The replacements parts need not necessarily be forged, but do need to be machined of a high quality tool steel. I buy as many parts as I can from Cylinder & Slide. Bill carries what I consider to be the best from many different makers. I always liked the Ed Brown safety for a 1911 and Bill had it, he has his own now. The parts are also available through Brownell's.
glockgazda
New member
I truly doubt that anyone forges small internal or external parts. If they did and sold them for a resonable price, they'd probably be supplier for the whole industry.
More likely parts like slide stop, thumb safety, spur hammers, etc, are cast and then machined.
Some parts that you can stack like ring hammers, sears, etc are wire EDM cut, and then machined if necessary.
What matters also is the heat treatment, and quality of steel used.
MIM parts are popular because they require very little final machining. IMO the jury is still out on MIM parts. No one ever did (publicly) any impact, tensile, hardness and wear tests on MIM vs. other parts. They are inferior, but how much, and is it acceptable? Yes some people that offer "Kimber upgrade packages" etc, have bitched about MIM parts, but that's part of their marketing. I guess street testing (shooting the guns) will show when there are 20,000 Kimbers out there, with 30,000 rounds shot through each.
If you want to play it super safe, get tool steel parts with best available heat treating. Then have them frozen, which changes the grain structure helping to reduce wear.
More likely parts like slide stop, thumb safety, spur hammers, etc, are cast and then machined.
Some parts that you can stack like ring hammers, sears, etc are wire EDM cut, and then machined if necessary.
What matters also is the heat treatment, and quality of steel used.
MIM parts are popular because they require very little final machining. IMO the jury is still out on MIM parts. No one ever did (publicly) any impact, tensile, hardness and wear tests on MIM vs. other parts. They are inferior, but how much, and is it acceptable? Yes some people that offer "Kimber upgrade packages" etc, have bitched about MIM parts, but that's part of their marketing. I guess street testing (shooting the guns) will show when there are 20,000 Kimbers out there, with 30,000 rounds shot through each.
If you want to play it super safe, get tool steel parts with best available heat treating. Then have them frozen, which changes the grain structure helping to reduce wear.
Those three parts generally work fine when made with MIM, as there is no real stress on any of them. Mainspring housings have been made of plastic and work. The other parts have almost no strain. MIM seems to be a poor choice for parts that have to withstand blows or have stress applied to them, like the barrel bushing (where the skirt takes a lot of strain), slide stop, and recoil spring guide.
Jim
Jim
Badger Arms
New member
HEY
WHAT IS MIM!!!!!!!!!!
WHAT IS MIM!!!!!!!!!!
Badger Arms
New member
I translate that as "Die Cast." Is this about right? Am I missing something? What's wrong with 'lost wax' casting like Ruger uses? Is MIM cheaper?
brianidaho
New member
My understanding of MIM is that it uses a powered metal in plastic "pellets". These pellets are injection molded in a mold; similar to any injection molded plastic part. I'm not sure what is different about the press and mold, I'd guess that there are a number of differences in them to withstand the abrasion of the metal powder. Anyway, the IM part uses the plastic as a binder to hold the metal powder in place. The part is then heated in a furnace to melt/burn off the plastic, and the metal particles are partially sintered. I believe these parts go through a second furnace operation to do additional sintering, thereby improving the strength and density of the part. The process has a lot more in common with typical powdered metalurgy than with conventional investment (lost wax) casting. It seems that I read that MIM parts "shrink" lots (like 30%) after injection molding and during the sintering process.
Heres a link to the Taurus site, it has a description of the process.
http://www.taurususa.com/tour1.html
Die casting involves directly injecting metal into a steel mold, somewhat like injection molding. The problem is that it typically works only with lower melting point materials (zinc, mag and aluminum). Investment casting works well with hi-strength steels and exotic alloys, but is a somewhat expensive process. At the very least investment cast parts need additional work to trim off gates (metal path used to fill the mold). There is quite a lot of work to mold the wax patterns, invest (make the ceramic coating) on them, melt off the wax and cast the parts.
Hope this helps.
Bri
Heres a link to the Taurus site, it has a description of the process.
http://www.taurususa.com/tour1.html
Die casting involves directly injecting metal into a steel mold, somewhat like injection molding. The problem is that it typically works only with lower melting point materials (zinc, mag and aluminum). Investment casting works well with hi-strength steels and exotic alloys, but is a somewhat expensive process. At the very least investment cast parts need additional work to trim off gates (metal path used to fill the mold). There is quite a lot of work to mold the wax patterns, invest (make the ceramic coating) on them, melt off the wax and cast the parts.
Hope this helps.
Bri