FullEffect1911
Member
Oh dear, I don't think PETA would like that at all.
If I can find my old one around I will.
SEM images - cross section of MIM and bar stock 1911 thumb safeties.
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Oh dear, I don't think PETA would like that at all.
If I can find my old one around I will.
So I cut up the MIM Kimber slide stop that came with my TEII. I cut off the pin that passes through the barrel link. My first impression was that this was a very dense and uniform part, then I started to look around, particularly near the outer edge and found some regions that didn't look quite so homogeneous. This indicates to me that it might be a challenge to make a part that is consistent throughout. Any part, regardless of how it's made, can fail, so take all of this for what it is.
The dark spherical "particles" are silicon, or at least, are showing high silicon levels. I don't know if these are artifacts from the injection or heat treating processes but they're not present in the cast part from Ed Brown. I'm more familiar with the heat treatment of aluminum alloys where spherical magnesium silicide precipitates during the heat treatment process. In aluminum, these precipitates add to the strength, but I don't know if the same is true for MIM parts.
Here's some info showing the elements in the Kimber thumb safety which has significantly more chromium and nickel compared to the slide stop.
Here's some info showing the elements in the Kimber slide stop.
The dark spherical "particles" are silicon, or at least, are showing high silicon levels. I don't know if these are artifacts from the injection or heat treating processes but they're not present in the cast part from Ed Brown. I'm more familiar with the heat treatment of aluminum alloys where spherical magnesium silicide precipitates during the heat treatment process. In aluminum, these precipitates add to the strength, but I don't know if the same is true for MIM parts.
Here's some info showing the elements in the Kimber thumb safety which has significantly more chromium and nickel compared to the slide stop.
Here's some info showing the elements in the Kimber slide stop.
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Big_E said:
They're images rather than photos (there's a difference) and I use an Hitachi S-3400N scanning electron microscope (SEM) with an Oxford Instruments Energy Dispersive X-ray Analysis (EDXA) detector to obtain the elemental data.
Toforo
Member
Ahh - those pics posted by the OP reminded me that I need to pick up bologna from the Deli in the morning and have it sliced thick -
Thanks!
Thanks!
Ah yes, I realize my mistake. I'm a biology student and have grown up around microscopes, I should have known better
. 1858, would you mind telling me what you do for a living? Or how you have access to such equipment.Thank you for taking these images, it can affect the argument of cast vs. MIM. While I am sure that some people with MIM parts haven't had a failure yet, if I am going to carry my 1911 (or any pistol) I sure do not want to risk the event of a part breaking. Plus, is there any regulation as to how many impurities are involved in the MIM process?
bnz43 said:
Typically cut with a low-speed diamond impregnated blade and polished using a slurry containing very small diamond particles. We have 30, 9, 3, 1, 0.5 and 0.05 micron solutions for polishing. I don't know if this interests you or not, but in order for scratches in metal to remain undetected using most imaging processes, the width and depth of the scratch needs to be less than about 0.3 microns since the shortest wavelength of visible light is 380nm. In other words, if the width/depth of the scratch is less than the shortest wavelength of visible light, no light can enter the scratch and be diffracted irregularly. It's variances in diffraction that reveal scratches.
Big_E said:
I'm a mechanical engineer working on projects funded by a number of branches of the armed forces including the Air Force, Army, Marine Corps and Navy. We're involved in material selection and testing, short and long-term testing of components and systems, coatings, corrosion control etc.
Big_E said:
This is my approach too. I only have two 1911s, one came with no MIM parts (Ed Brown) and other came with a bunch (Kimber TEII) but I replaced most of the MIM parts. I shoot the Kimber a lot i.e. a rate of about 10,000 rounds per year and many of those rounds are in matches. I might shoot more than that this year if I can take a two or three-day course from Bruce Gray which is my plan.
My feelings at this point are that MIM serves a purpose for many owners and for manufacturers. MIM helps to reduce cost, provides sufficient quality and longevity for many and makes the swapping of parts easier (less fitting) which is good for the end user. However, some parts are more critical than others depending on the loading and fatigue along with the number of defects in the part. I still feel that I have less chance of a catastrophic failure in a match or class if I'm using high quality bar stock, forged or cast parts compared to MIM. Peace of mind is important, even if it's based on a false premise.
Big_E said:
This would be negotiated between the manufacturer of the MIM parts and the firearms manufacturer assuming they're not one and the same. For example, I'm sure that Kimber cuts up MIM parts and inspects them to determine if the chemistry and heat treatment are acceptable. They'd also inspect the parts to ensure that they're dimensionally accurate. The problem is that you can't cut up every part so it's a statistical process where you're confident of X number of parts being "good enough".
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Zerodefect
member
My EB big paddle thumb safety is Cast. LB is cast. STI cast. Most Wilsons are cast.
The only billet and forged thumb safeties I know of are Wilsons top shelf safety (thier lower models are cast), and the Dan Wesson thumb safety on the 2010+ Valors and Vbobs.
The only billet and forged thumb safeties I know of are Wilsons top shelf safety (thier lower models are cast), and the Dan Wesson thumb safety on the 2010+ Valors and Vbobs.
Hangingrock
Member
There is in every design cost and effect. How many $2500-$3500 1911 series pistols are sold in comparison to the polymer frame striker fire pistols that dominate the market place? Yes-yes I know apples oranges comparison but which is more cost effective and or durable.
It would be enlightening to conduct a 50,000 (just as an example) round endurance test of a high end 1911 and a Glock/S&W polymer framed striker fired pistol and see which one gives up the ghost first.
There are certain designs which one could say are over engineered for the application and then there are good enough designs for the application. None the less cost is an issue like it or not.
It would be enlightening to conduct a 50,000 (just as an example) round endurance test of a high end 1911 and a Glock/S&W polymer framed striker fired pistol and see which one gives up the ghost first.
There are certain designs which one could say are over engineered for the application and then there are good enough designs for the application. None the less cost is an issue like it or not.
Nice comparison. The MIM parts definitely have a higher defect density. I used to do SEM work for 7 years in semiconductors. A+ on imaging and EDX data collection.
I think you've illustrated the MIM, Non-MIM part differences quite well. All this "good enough" talk is fine and the engineers overseeing the mfg process will be putting the metric on the "good enough" (acceptable) defect density levels. But the data clearly illustrates to me that a machined part will be more reliable than a MIM'd part based upon empirically observed defect density level comparison. There's simply more opportunity for failure with higher defect levels in the MIM parts in this example.
I think you've illustrated the MIM, Non-MIM part differences quite well. All this "good enough" talk is fine and the engineers overseeing the mfg process will be putting the metric on the "good enough" (acceptable) defect density levels. But the data clearly illustrates to me that a machined part will be more reliable than a MIM'd part based upon empirically observed defect density level comparison. There's simply more opportunity for failure with higher defect levels in the MIM parts in this example.
Jolly Rogers
Member
1858....nice toys! I would like to have a barstock part and a forged part cut and imaged also. This could be the definitive thread about quality in MIM, cast,barstock and forged parts. The arguments would all cite this thread. There was a nice thread over at the 1911 forum in the gunsmithing subforum about slide stops and thumb safty quality but it is not accessable at this time. Weeks down for maintenance... I hope it comes back as I would reference this data.
Many thanks for your effort. If I had any parts to add to the database I would send them..alas...
Joe
There was a nice thread over at the 1911 forum in the gunsmithing subforum about slide stops and thumb safty quality but it is not accessable at this time. Weeks down for maintenance... I hope it comes back as I would reference this data.Many thanks for your effort. If I had any parts to add to the database I would send them..alas...
Joe
918v said:
Take that thread for what it was, interesting and mysterious images of S&W and Ruger cylinders and nothing more. Many manufacturers use proprietary materials and techniques and guard them closely and Ruger is no exception. I don't think any company wants enthusiasts like me cutting up their parts and posting results on the internet. My take is that if you have nothing to hide then you'll bend over backwards to help those individuals spread "the good word". However, I was contacted by Ruger's Associate General Counsel and I have little doubt that they were flexing their muscles. I took the hint. If you notice, I'm simply providing images and EDXA data without offering any significant conclusions. The last thing I need is Kimber's legal department sending me an email.
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Jolly Rogers
Member
The photos are prima facie evidence of the comparative quality of the parts, and need no comment.
Joe
Joe
Pizzagunner
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My personal take on MIM is this: There are pistols that are designed from the clean sheet that take into account that certain of its parts will be MIM from the get go. The S&W M&P series would be a prime example of such a design. M&Ps have put up impressive round counts without its MIM sear failing catastrophically. The wear characteristics, impact resistance, etc., were all taken into account in the CAD/CAM process and confirmed through developmental testing and field use.
OTOH, MIM is also being adapted to parts for designs that were made before MIM was a process, (1911s, SIG P22x, S&W revolvers, etc.). These are the applications of the technology that I do not fully trust as what has actually happened is a material strength downgrading that was not accounted for in the original design engineering, developmental prototyping, nor years to decades of field use.
Coming full circle to the M&P. Suppose that a decade from now S&W decides that a hard polymer sear will wear and perform "well enough" to replace the MIM sear. I'd find that claim suspect and more likely a child of the accounting and legal departments than of the R&D department, absent any widely publicized general breakthrough technologically in wear resistant polymers.
MIM is a fine technology when properly used in a dedicated design application. Using it to replace bar stock parts or quality IC parts on vintage designs is a cost cutting strategy that is not also in the best interests of the end user on any other front save price.
OTOH, MIM is also being adapted to parts for designs that were made before MIM was a process, (1911s, SIG P22x, S&W revolvers, etc.). These are the applications of the technology that I do not fully trust as what has actually happened is a material strength downgrading that was not accounted for in the original design engineering, developmental prototyping, nor years to decades of field use.
Coming full circle to the M&P. Suppose that a decade from now S&W decides that a hard polymer sear will wear and perform "well enough" to replace the MIM sear. I'd find that claim suspect and more likely a child of the accounting and legal departments than of the R&D department, absent any widely publicized general breakthrough technologically in wear resistant polymers.
MIM is a fine technology when properly used in a dedicated design application. Using it to replace bar stock parts or quality IC parts on vintage designs is a cost cutting strategy that is not also in the best interests of the end user on any other front save price.
Pizzagunner
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His statement is a very paranoid reading of the exchanges with Ruger he posted in that thread. I don't even like Ruger, they were just saying that the information sought was proprietary. Then another source at Ruger told him that the cylinders in question were milled from different formulations of bar stock, which just happens to jibe with what two people who've actually toured Ruger's NH facility said in a book and live within that thread.
You can boycott Ruger for all I care, but don't base it on 1858's reading of emails he published in a thread, emails which would threaten no rational person, and which didn't even chill him enough to dissuade him from pressing Ruger for "non-proprietary" ways of answering his queries, which they did.
If they were "flexing their muscle" he's only seen it in retrospect.
You can boycott Ruger for all I care, but don't base it on 1858's reading of emails he published in a thread, emails which would threaten no rational person, and which didn't even chill him enough to dissuade him from pressing Ruger for "non-proprietary" ways of answering his queries, which they did.
If they were "flexing their muscle" he's only seen it in retrospect.
Ridgerunner665
Member
I like Glocks...but if you shot the pistols until the frame got hot enough to melt, the 1911 would win. (Glock frames will start to droop after a while...)
Pizzagunner said:
Not only are your comments inaccurate, they're also naive. Only one individual contacted me from Ruger and that was their Associate General Counsel in my response to an email that I sent to customer service. Is this normal operating procedure to you? A question directed to customer service gets answered by the company's legal counsel. This isn't some rinky dink small business, this is a publicly traded company on the NYSE. I found it odd at the time, and still do, but that thread had run its course so I backed away graciously. I knew that no further progress was possible without cutting up those cylinders and having experts in the field of casting look at them. Passivation processes won't affect the internal structure but I wasn't prepared to sacrifice my cylinders for this forum. That's too much cost for something that really isn't that important. I love Ruger revolvers and currently have six of them with plans for more. Ultimately, does it matter how Ruger makes their product if they work, which they do?
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