:confused: Broke my LMT - MRP Locking Bolt!!!
- Thread starter Adamg_55
- Start date
- Location
- 54°52'56"N 112°10'7"W Alpha Bravo
Why?
Ok, I read this thread last night and had a good chuckle at all the comments before bed. Today I thought I'd post. This is what it all boils down to:
LMT has a valid concern that many customers out there will strip and destroy their $1700 Uppers and want new ones because many customers don't know how to properly fasten a bolt. LMT is in a potentially costly bind, they could be seen as dicks for taking the logical approach of "you break it, you already bought it" but, I imagine internet hate would go through the roof; 140in/lbs is easy to exceed. "LMT junk... my $1700 upper is garbage and they won't replace it!"
The solution (based on what I am reading here) was a bolt that would shear when too much torque is applied.
If you are mechanically capable, these "special $50 bolts" are not required. If you have no idea what a torque wrench is and always reef on wrenches to make sure "it's tight" then you definitely need the "$50 bolts".
I myself have built several engines in my day and would feel comfortable using a regular bolt as I learned a long long time ago that it doesn't take much to do damage from over-tightening.
It's often people with little mechanical knowledge who feel they need the summon the strength of Hercules to "snug-up" that last hex screw.
Stripped threads from over tightening are always the end-users/installers fault.
These "special" bolts are LMT's way of avoiding headache/Bad-Press IMO; they have to take a firm stance on making sure everyone uses these bolts to avoid the original scenario (especially now that they've gone through the hassle of making these special bolts).
This is all just my opinion of course.
The end.
LMT has a valid concern that many customers out there will strip and destroy their $1700 Uppers and want new ones because many customers don't know how to properly fasten a bolt. LMT is in a potentially costly bind, they could be seen as dicks for taking the logical approach of "you break it, you already bought it" but, I imagine internet hate would go through the roof; 140in/lbs is easy to exceed. "LMT junk... my $1700 upper is garbage and they won't replace it!"
The solution (based on what I am reading here) was a bolt that would shear when too much torque is applied.
If you are mechanically capable, these "special $50 bolts" are not required. If you have no idea what a torque wrench is and always reef on wrenches to make sure "it's tight" then you definitely need the "$50 bolts".
I myself have built several engines in my day and would feel comfortable using a regular bolt as I learned a long long time ago that it doesn't take much to do damage from over-tightening.
It's often people with little mechanical knowledge who feel they need the summon the strength of Hercules to "snug-up" that last hex screw.
Stripped threads from over tightening are always the end-users/installers fault.
These "special" bolts are LMT's way of avoiding headache/Bad-Press IMO; they have to take a firm stance on making sure everyone uses these bolts to avoid the original scenario (especially now that they've gone through the hassle of making these special bolts).
This is all just my opinion of course.
The end.
Hmmm… Yes let us recap this thread. The bolts are special for two reasons. First, they break before damaging the upper. Second, they are machined to precisely fit the barrel. People make dumb mistakes sometimes, even mechanically inclined people. I am pretty sure Adamg oiled his bolts, as he says he had a “well lubed rifle” before installing them. As 50calshooter said he had a faulty torque wrench included with his LMT. Imagine if either of them didn’t realize these things and bought some 50 cent hardware store bolts as many people told them to.
You know people make stupid mistakes. Would you prefer to have LMT bolts or hardware store bolts when you make that stupid mistake? If you never over-tighten things you would have no need to replace them. IMHO stick with the LMT bolts.
Oh, and I have never heard of LMT bolts coming loose.
You know people make stupid mistakes. Would you prefer to have LMT bolts or hardware store bolts when you make that stupid mistake? If you never over-tighten things you would have no need to replace them. IMHO stick with the LMT bolts.
Oh, and I have never heard of LMT bolts coming loose.
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- Location
- 54°52'56"N 112°10'7"W Alpha Bravo
I get it, it makes sense, but really it's a moot point. If you know how to properly torque bolts then you wouldn't need to run hardware store bolts because you wouldn't need to replace the LMT ones, right?
If you do end up breaking the factory bolts, then perhaps you should stick to the factory replacements for the peace of mind. They are not $50 dollars each there about 15 bucks each, for the 30 dollars thats some cheap piece of mind right there. LMT replaced mine for free, and I still chose to wait for them before buying cheap hardwares store ones, I didn't wanna risk my warranty.
At the end of the day it's the OP's choice, if he gets a good quality torque wrench and feels confident, then go for it.
Actually most firearms companies that manufacture most of their products (i.e. LMT, FN, Daniel Defense, and us here at KAC) do have screw machines. I do know for a fact LMT has one (four I think but who's counting), and does make their bolts.
We at KAC have 3 - we make screws, extractors and a number of other things on them - shocking I know...
We at KAC have 3 - we make screws, extractors and a number of other things on them - shocking I know...
People seem confused here. Even if there was no issue with the torque, you still need to use the LMT bolts since they are used for locating the barrel and are responsible for the barrel fit. They have a specific diameter and cylindricity that you need for a good fit on the barrel.
Don't spread the rumour that you can use any old bolt if you know how to tighten it. That simply is not true.
Don't spread the rumour that you can use any old bolt if you know how to tighten it. That simply is not true.
Actually most firearms companies that manufacture most of their products (i.e. LMT, FN, Daniel Defense, and us here at KAC) do have screw machines. I do know for a fact LMT has one (four I think but who's counting), and does make their bolts.
We at KAC have 3 - we make screws, extractors and a number of other things on them - shocking I know...
Screw machines (which are typically cut thread) or thread ROLLING machines like bulk fastener companies use? Two very different animals and orders of magnitude difference in tooling costs.
Usually only big fastener manufacturers can afford to roll threads. We make fasteners all the time and have both machines where I work. what we use depends on a lot of factors, but for bulk runs in the 100's of thousands, you always default to a rolling setup.
The fact that the LMT fasteners are ground to diameter also guarantees the threads are not rolled. You can only surface grind fastener shafts on a screw CUTTING machine (which is really a specialized lathe). Screw rolling machines cold-work the part to diameter - no grinding involved.
- Location
- 54°52'56"N 112°10'7"W Alpha Bravo
This argument is pointless, you only brought it up because you were so sure LMT didn't make there bolts in house. You were so sure it had to be some random big company everyday fastener.
Let it go already you were wrong. LMT makes there own s**t, and how they make them is irrelevant to this topic. Now you're just back pedaling trying to prove your knowledge of fasteners. Who cares.
??? Are you always abrasive or do you try hard just for this board?
YES, I was wrong that LMT didn't use standard fasteners for this application. Had I designed the gun, I would have - even if it meant using a steel insert in the frame to prevent thread stripping. I find screws designed to fail to be a supreme annoyance - I much prefer to design things bullet-proof where possible. I'm sure you knew they made custom ground and cut fasteners all along and aren't just riding the Questar coat tails. (actually I DON'T believe you).
And for the record, I doubt very much LMT makes every fastener - it would not be cost effective and almost nobody does that. Things like set screws, the screw that holds the grip on, etc. are generally not custom fasteners on the guns made by most manufacturers. This is a fact. Maybe LMT makes them themselves in every instance, but that would put them in a very small minority and un-necessarily increase the price of their products.
Maybe there's something about the MRP design I'm not grasping (I've shot them but don't own one I can go reference) but it would seem foolish to rely on a precisely ground screw diameter to properly locate and fix the barrel. Unless you need to hammer the screws out with a punch, there would be enough clearance that a rolled standard fastener would be FINE. Typically you have at least 7-9thou clearance between a fastener and a hole to make sure it goes in and out reliably without galling the aluminum. A rolled standard fastener can be made with under 5 thou tolerance as small as M4 diameter quite easily and cheaply.
But then - a lot of manufacturer's over-design and over-build product to impress the average buyer. Goggle 45 jewel watches. People used to perceive more jewels = better quality. Most ppl did not know that a standard watch could only use 21 jewels effectively - the rest was just decoration.
YES, I was wrong that LMT didn't use standard fasteners for this application. Had I designed the gun, I would have - even if it meant using a steel insert in the frame to prevent thread stripping. I find screws designed to fail to be a supreme annoyance - I much prefer to design things bullet-proof where possible. I'm sure you knew they made custom ground and cut fasteners all along and aren't just riding the Questar coat tails. (actually I DON'T believe you).
And for the record, I doubt very much LMT makes every fastener - it would not be cost effective and almost nobody does that. Things like set screws, the screw that holds the grip on, etc. are generally not custom fasteners on the guns made by most manufacturers. This is a fact. Maybe LMT makes them themselves in every instance, but that would put them in a very small minority and un-necessarily increase the price of their products.
Maybe there's something about the MRP design I'm not grasping (I've shot them but don't own one I can go reference) but it would seem foolish to rely on a precisely ground screw diameter to properly locate and fix the barrel. Unless you need to hammer the screws out with a punch, there would be enough clearance that a rolled standard fastener would be FINE. Typically you have at least 7-9thou clearance between a fastener and a hole to make sure it goes in and out reliably without galling the aluminum. A rolled standard fastener can be made with under 5 thou tolerance as small as M4 diameter quite easily and cheaply.
But then - a lot of manufacturer's over-design and over-build product to impress the average buyer. Goggle 45 jewel watches. People used to perceive more jewels = better quality. Most ppl did not know that a standard watch could only use 21 jewels effectively - the rest was just decoration.
Its not impossible that they make their own screws.
I'm just wondering at the ROI over having a specialty mfg make them.
Google torque limiting fastener. You'll find many companies that make them, and it is literally all that they do. That know-how is very hard to replicate. Its a long way from your trolling attempt to reduce leading fabricators as random. And yes, I do understand in house capability, local stocking, direct revision control and all the in-house advantage over production quality control. I also understand terms like bankruptcy, insolvency and return on investment.
People who make those kinds of buying choices don't validate them on gut feelings.
To be fair, most of us have TSROFA what LMT makes. Or for who. By example, for several years we made automated doughnut cutter systems for Tim Hortons (you're welcome). They make kick off a volume of secondary and tertiary product lines that offset the cost. Or it might be part of risk management as others indicated. It sure as hell isn't CRF. (Google it)
But excuse me if I wait for someone like KevinB to chime in to confirm that they actually HAVE such a capability. If I had a dollar for every inaccurate or even preposterous piece of information over 400 employees handed out over 5 years, I'd be long retired.
At one point we subcontracted t1ctacal in to do FEA on a new tower line we were manufacturing. Our structural engineering lead (senior ex-Nortel employee) was creating a job spec that entirely contradicted the very same government regulations he was citing as specific, bona fide tower requirements. I don't believe he even read the f**king document for his own meeting. Ate up a dozen P.Eng and M.Eng's blindingly expensive time with his bulls**t version of the proper manufacturing.
And then, not exactly advertised on our line card, but with 150,000 sq ft of plastics and metals manufacturing and finishing we needed to pay the bills for some very expensive equipment. Despite rolling off large volumes of mainstream production.
Wrong? Sure. I guess they have one after all. Best way to go about it? I'd never go that route.
But I think you might want to be mastering personal use of the torque wrench before attempting to educate some folks about finer points of managing mech e production. Or any other discipline for that matter. Claven, you were wrong too..
Wrong, I tell you.
While we're pointing out people hopelessly wrong though, maybe you can say 'hi' to dad for me Claven, because 50 cal seemed to confuse you with my brother.
I'm just wondering at the ROI over having a specialty mfg make them.
Google torque limiting fastener. You'll find many companies that make them, and it is literally all that they do. That know-how is very hard to replicate. Its a long way from your trolling attempt to reduce leading fabricators as random. And yes, I do understand in house capability, local stocking, direct revision control and all the in-house advantage over production quality control. I also understand terms like bankruptcy, insolvency and return on investment.
People who make those kinds of buying choices don't validate them on gut feelings.
To be fair, most of us have TSROFA what LMT makes. Or for who. By example, for several years we made automated doughnut cutter systems for Tim Hortons (you're welcome). They make kick off a volume of secondary and tertiary product lines that offset the cost. Or it might be part of risk management as others indicated. It sure as hell isn't CRF. (Google it)
But excuse me if I wait for someone like KevinB to chime in to confirm that they actually HAVE such a capability. If I had a dollar for every inaccurate or even preposterous piece of information over 400 employees handed out over 5 years, I'd be long retired.
At one point we subcontracted t1ctacal in to do FEA on a new tower line we were manufacturing. Our structural engineering lead (senior ex-Nortel employee) was creating a job spec that entirely contradicted the very same government regulations he was citing as specific, bona fide tower requirements. I don't believe he even read the f**king document for his own meeting. Ate up a dozen P.Eng and M.Eng's blindingly expensive time with his bulls**t version of the proper manufacturing.
And then, not exactly advertised on our line card, but with 150,000 sq ft of plastics and metals manufacturing and finishing we needed to pay the bills for some very expensive equipment. Despite rolling off large volumes of mainstream production.
Wrong? Sure. I guess they have one after all. Best way to go about it? I'd never go that route.
But I think you might want to be mastering personal use of the torque wrench before attempting to educate some folks about finer points of managing mech e production. Or any other discipline for that matter. Claven, you were wrong too..
Wrong, I tell you.
While we're pointing out people hopelessly wrong though, maybe you can say 'hi' to dad for me Claven, because 50 cal seemed to confuse you with my brother.
Does LMT use a bolt of their own design or does it conform to an existing standard? That looks very much like a pretty standard DIN standoff(?) socket cap screw. It certainly does not look like a regular partially threaded socket cap screw as Neit suggested.
I could certainly see manufacturing your own bolts, if you are using it as a centering device and you need to ensure conformity between all parts... the only way to know something is done right, is to do it yourself.
I could certainly see manufacturing your own bolts, if you are using it as a centering device and you need to ensure conformity between all parts... the only way to know something is done right, is to do it yourself.
Claven, you were wrong too..
Wrong, I tell you.
While we're pointing out people hopelessly wrong though, maybe you can say 'hi' to dad for me Claven, because 50 cal seemed to confuse you with my brother.
LOL. Sure thing "Bro". LOL
And yes, I get that I was wrong about LMT not making some of their own fasteners. Mea Culpa.
Frankly though, it seems odd to me they would make fasteners for themselves if they are not selling fasteners independent of the AR manufacturing business. It doesn't make good engineering or business sense to me.
What do I know though? I've only been at this for 15 years... Of course, I understand there are many ways to skin a cat - LMT just does it differently than I would do it.
I would argue that's not quite accurate. Any ISO 9001 certified fastener manufacturer can make fasteners in large lots more effectively than LMT could make them (unless they make fasteners for other than rifle building??).
Making small batches is never cost effective. When we make a one-off precision fastener, they can often cost several hundred dollars each if the quality requirements and quality evidence documents that go with it are thorough. The same fastener made in larger quantities becomes a lot less expensive per unit.
At the end of the day, you can order fasteners with any spec, including torque-limited fasteners with precision ground shafts, and there are lots of specialty companies that will make them in the thousands for very competitive prices.
I think what it boils down to is that when you buy an LMT AR, it is recognized by many that you are paying a premium for what the buyer perceives as "top quality" - better than a run of the mill Stag or Armalite or whatever. This means LMT is expected to retail at a premium price point and they don't care if they pass on a $15 socket head cap screw to the consumer because people will gladly pay without questioning it. It's a market strategy that seem to be proven and that works for them.
I doubt Norinco or Olympic Arms or Vulcan could get away with having any of their fasteners cost $15 though. Those brands have enough trouble keeping an image as a quality gun. Breaking one and needing a "$15 screw" would maybe sink them as a manufacturer. Think about it.
- Location
- 54°52'56"N 112°10'7"W Alpha Bravo
You pay a premium because it IS top quality, period.
LMT has some of the best products out right now. Even better, they actually care about the Canadian market. For someone that doesn't own LMT, you sure act like you know alot about their products and how their business should be run. Why are you so butt hurt by the way they run their business? Maby the reason those bolts cost so much is because they're costly to make. Maby they prefer building every component in-house. Maby that's part of their quality control standards. Maby that's why they produce quality. What they do obviously works, their track record speaks for itself. It may not make sense to you, but hey, you're in the fastener business not the gun manufacturing business.
Fuller metric is supposed to be ISO certified, and while factories in China actually produce their products, Fuller does not seem to verify that the fasteners meet specifications. I've received a number of fasteners from fuller that I've had to re-order from fabory, in order to get fasteners that actually meet the specifications of the DIN drawing.
That being said I almost exclusively use DIN fasteners, but even at that they still do not meet spec unless I source them from a quality supplier such as fabory.
Even when sourcing fasteners from fabory there are the occasional pieces that clearly missed a stage of the QC process, making them in house would mean that you would only have your QC personal to blame if something is wrong.
