new_scopeshooter
New member
Looking for suggestions is the gunsmithing world for a good quality tourqe wrench. I have a nice snap on that does from 30-200 inch pounds. I know wheeler makes one. What are the other companies that you smiths use
Tourqe wrench suggestions
- Thread starter new_scopeshooter
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Dixie Gunsmithing
Moderator Emeritus
Weaver has a small torque driver set, made for installing scopes. I doubt that it or the one by Midway are as accurate as a precision torque driver; probably only within a couple of pounds +/-. I have a Weaver, myself. You don't need to worry about one being more accurate than within a couple of pounds, really, for rings and bases, as they'll work.
You can use a small ratchet, too, as they go down in that range of torque, or the 1/4" does.
You can run across used precision ones on eBay. They still cost a good bit of cash though. Generally, these come out of aircraft factories, and precision manufacturing plants. Their accuracy will be questionable, without calibration, which is expensive in itself. That is, unless you can find one with an up-to-date calibration label on it.
You can use a small ratchet, too, as they go down in that range of torque, or the 1/4" does.
You can run across used precision ones on eBay. They still cost a good bit of cash though. Generally, these come out of aircraft factories, and precision manufacturing plants. Their accuracy will be questionable, without calibration, which is expensive in itself. That is, unless you can find one with an up-to-date calibration label on it.
I know, sounds cryptic, I fail to understand why a user can not test a torque wrench for accuracy. Then there is that part abort being expensive.
I was under the impression Craftsman had a warranty. I took one to their repair canter. They wanted $80.00 to repair or replace. I refused their generous ? offer. I said a better option would be Harbor Freight, for $80.00 I could purchase 5 torque wrenches.
The torque wrench that was destroyed was a torque wrench I had loaned. There was nothing on the wrench that was salvageable.
F. Guffey
new_scopeshooter
New member
Thanks looks like I will order a wheeler next week!
Dixie Gunsmithing
Moderator Emeritus
F. Guffey, We can test our own torque wrenches with a weight on an arm to get it close, and eBay has used calibration machines for drivers and wrenches that I've seen for sale. We gunsmiths don't need anything that is that critically precise, I don't think, as compared to how some factories do, that have to keep up a calibration service program over law suits.
I bought a 1/4" torque wrench from Harbor Freight, and it seems to work all right. I'd say that as new, their calibration is spot on. The hand drivers, though, like Harbor Freight had, and like Midway and Weaver sell, I doubt, are that accurate. They work similar to the overload clutch on a battery powered drill. My guess is that they are something like +/- 2 pounds on their highest range, and maybe a 5% tolerance or so. They don't give a calibration sheet with them, so it is an unknown.
I bought a 1/4" torque wrench from Harbor Freight, and it seems to work all right. I'd say that as new, their calibration is spot on. The hand drivers, though, like Harbor Freight had, and like Midway and Weaver sell, I doubt, are that accurate. They work similar to the overload clutch on a battery powered drill. My guess is that they are something like +/- 2 pounds on their highest range, and maybe a 5% tolerance or so. They don't give a calibration sheet with them, so it is an unknown.
For the gunsmithing work I am doing, I don't need the torque be spot on accurate, as long as it is consistent. I have a Weaver fat driver. It is plenty enough.
There are cheap stuff from harbor freight, then there are regrets at least 75% of the time after I buy the stuff. Now I only buy from them stuff that I don't care about.
-TL
There are cheap stuff from harbor freight, then there are regrets at least 75% of the time after I buy the stuff. Now I only buy from them stuff that I don't care about.
-TL
Really, using a torque wrench or driver on scope bases and rings is more about consistency and not over torquing the screws than it is about exactly the torque applied. All fasteners have a torque limit, and most people dont know what it is. Even if you do know what it is, having the feel to hit close to it would require a rather constant repitition of the act, which most gunsmiths dont do. The smaller diameter the screw, the lower the torque it can handle. Over torquing the screws will stress the hardened screw shank, causing it to fatigue and break, or start to stretch the threads in either the hole or the screw, causing them to fail, either immediately, if seriously stretched, to the point of stripped, or later, again from fatigue.
The base screws, for instance, are already holding against a shear load in most instances. Some bases have a recoil lug, which takes most of the load off the screws.
So, + or - a couple inlbs isnt going to really hurt anything, but some way over tight, and some loose are bad. All way over tight or way loose is also bad.
The base screws, for instance, are already holding against a shear load in most instances. Some bases have a recoil lug, which takes most of the load off the screws.
So, + or - a couple inlbs isnt going to really hurt anything, but some way over tight, and some loose are bad. All way over tight or way loose is also bad.
When I did that in 2011 and talked to my wife, who designs calibrators, she said that I was using the weight scale as the standard.
https://en.wikipedia.org/wiki/Measurement
Whenever I talked to my father, who designed guns and vehicles, he called it a the weight force a moment arm.
https://en.wikipedia.org/wiki/Moment_(physics)
I still don't have their lingo, you can hear my voice measuring 540 foot pounds
https://www.youtube.com/watch?v=YOjYro4w0Bc
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kilimanjaro
New member
Test your torque with a weight, just to determine if it is reasonably accurate, say 10% to 20% plus/minus, then use it for consistent work, that's more important than absolute accuracy.
Use a weight that will test it out at the loads you will be using, if your specified torque for much of your uses will be say, 50 inch-pounds, test there, not at 200 inch-pounds where you will never or seldom go.
Use a weight that will test it out at the loads you will be using, if your specified torque for much of your uses will be say, 50 inch-pounds, test there, not at 200 inch-pounds where you will never or seldom go.
I worked PMEL at Kelly AFB and re-certified torque wrenches every year. I only ever had 3 go out of calibration. 2 I was able to do myself and one had to be scrapped. All of them were over 10 years from their 1st calibration. This is out of 2000 or so torque wrenches I did over 2 years. The tester is a weighted pendulum.
Dixie Gunsmithing
Moderator Emeritus
Clark, I was taught as your father, as the load on the wrench is a moment arm. If you have a rod, with a socket attached, so as to mount it to the wrench with, you have to weigh it, and measure the length from the center of gravity, to the center of the socket, in inches, to get the moment calculated for the arm, so you know how big to make the weight, or how much to add to each setting. At that, the arm has to be sticking out from the wrench, parallel to the floor, or level, with the weight acting at 90 degrees to it, and be adjustable along the rod by an inch or metric scale, unless it is a fixed value.
An example, would be, that the moment arm was a metal rod, 12" long, from the center of the socket, to it's end, and weighed 2 pounds. Then, when checked, the rod balances, (its center of gravity or C.G.), at 6" out. You simply multiply the two, to get 12 inch pounds, (6" x 2 Lb.), which will have to be added to the torque from the weight you will add on the rod, to slide along it. If the sliding weight weighed 5 pounds, and its C.G. was at the end of the rod, that would be 5 lb. x 12", or 60 inch pounds, but you still have to add the 12 inch pounds from the rod, so it will really be 72 inch pounds. It's the same as mounting two moment arms on the same axis, and adding the two together to get the total.
The above would be for a pendulum type calibrator.
The other calibrators, that I've seen, have a strain gauge in them, with a digital readout, that you bolt to a workbench. You just watch for the wrenches torque setting, in In-Lb or Ft-Lb, to come up on the LED readout, as you turn the wrench, and see if the wrench will click when it gets to the proper torque. The thing is, the calibrator has to be calibrated and re-calibrated, too, if you want it really accurate. To me, the simple pendulum type would actually be more accurate, for a longer time, once every moment is calculated, and added up. Especially a fixed value pendulum, except you can't adjust these until the wrench clicks, and read the measurement off a scale.
That wrench wasn't that accurate, then, as I figured it would be, if new. However, you do have the correct idea about checking one, as long as you know the measurement, from the center of the socket, to the C.G. of the weight. Make sure the wrench is level, and the weight known. Also, to do it your way, you need to weigh the wrench, and find its C.G., to know it's own moment. You'll have to add the wrenches moment to the weights moment, as that could be throwing your calculation and test way off on the low end.
An example, would be, that the moment arm was a metal rod, 12" long, from the center of the socket, to it's end, and weighed 2 pounds. Then, when checked, the rod balances, (its center of gravity or C.G.), at 6" out. You simply multiply the two, to get 12 inch pounds, (6" x 2 Lb.), which will have to be added to the torque from the weight you will add on the rod, to slide along it. If the sliding weight weighed 5 pounds, and its C.G. was at the end of the rod, that would be 5 lb. x 12", or 60 inch pounds, but you still have to add the 12 inch pounds from the rod, so it will really be 72 inch pounds. It's the same as mounting two moment arms on the same axis, and adding the two together to get the total.
The above would be for a pendulum type calibrator.
The other calibrators, that I've seen, have a strain gauge in them, with a digital readout, that you bolt to a workbench. You just watch for the wrenches torque setting, in In-Lb or Ft-Lb, to come up on the LED readout, as you turn the wrench, and see if the wrench will click when it gets to the proper torque. The thing is, the calibrator has to be calibrated and re-calibrated, too, if you want it really accurate. To me, the simple pendulum type would actually be more accurate, for a longer time, once every moment is calculated, and added up. Especially a fixed value pendulum, except you can't adjust these until the wrench clicks, and read the measurement off a scale.
That wrench wasn't that accurate, then, as I figured it would be, if new. However, you do have the correct idea about checking one, as long as you know the measurement, from the center of the socket, to the C.G. of the weight. Make sure the wrench is level, and the weight known. Also, to do it your way, you need to weigh the wrench, and find its C.G., to know it's own moment. You'll have to add the wrenches moment to the weights moment, as that could be throwing your calculation and test way off on the low end.
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FrankenMauser
New member
....Unless it has been dropped 20 feet from the tail rotor of a helicopter.
We used to have about one torque wrench per week get dropped off of the helicopters (H-53s, not something like teeny little Robinsons). Generally, the smaller the wrench, the more likely the calibration would be just fine. And, the higher the torque value it was set to at the time, the better. But, the larger the wrench, the more likely it was not just in need of calibration, but completely toast.
Any torque wrench that got dropped more than 12" was sent in for calibration. But, often, our BIG torque wrenches (48+" long, 3/4" drive, 100-600 lb-ft or more) would never come back - especially if the fall was from the tail or the top of the helicopter (12-26 feet). They'd be declared scrap, and we'd have to call the Snap-On dealer and fork over another $800 per wrench.
But, the bad ones...
The bad ones just got sent to DRMO/DLA, and got auctioned off with all of the other crap that .gov was liquidating. Most of them still had "valid" calibration stickers, too.
As for me... I just use Harbor Freight torque wrenches. They're close enough for government work (actually, I guess not... but they're close enough for me).
One thing that I still do - probably unnecessarily - that was pounded into me in the military, is to never use a torque wrench within 10% of a minimum or maximum setting. That's how they were calibrated, as well - only from 10% above minimum to 10% below maximum.
It was a legitimately punishable offense on the helicopters. But, in my own shop, on things FAR, far less critical... I still adhere to that rule.
Dixie Gunsmithing
Moderator Emeritus
FrankenMauser, Exactly! Especially on used wrenches.
Aircraft, automobiles, etc., have to use calibrated wrenches in the factory, and really, it more over law suits, because if a bolt breaks, and a attorney claims it was over or under tightened, which caused injury or death, well, there's the suit. Manufacturers, large service shops, and as you mentioned, our government, spend a ton of money on calibration for many tools over this.
I used to work in the engineering department, for a mining machine manufacturer, and we were sued a few times. (We never had one over bolt breakage while I was there, though). On one suit, the guy tried to claim the battery on his belt hit the drill lever, and mashed his hand between the drill head and the roof. It shouldn't have been possible. Believe it or not, when we set up a full scale model, and asked him to show us how it was done, it came out, from another mine employee, that he purposely mashed his hand in order to retire early, and get a large settlement from workers comp. The guy dropped the suit, and never showed up for the test. However, all it would take, would be a bolt or screw to break, to cause something similar, and you would have a similar suit.
In guns, though, we are fortunate enough to not have critical fasteners. The worst we have, (as far as stripping or breaking), are the small ones, for scopes, etc. I always wondered what would happen if a stock bolt broke, when fired, and the gun came back and injured someone. That is a possibility for some designs. The only other place, would be barrel nuts or threads. Here, the military has a torque limit on the AR designs.
Aircraft, automobiles, etc., have to use calibrated wrenches in the factory, and really, it more over law suits, because if a bolt breaks, and a attorney claims it was over or under tightened, which caused injury or death, well, there's the suit. Manufacturers, large service shops, and as you mentioned, our government, spend a ton of money on calibration for many tools over this.
I used to work in the engineering department, for a mining machine manufacturer, and we were sued a few times. (We never had one over bolt breakage while I was there, though). On one suit, the guy tried to claim the battery on his belt hit the drill lever, and mashed his hand between the drill head and the roof. It shouldn't have been possible. Believe it or not, when we set up a full scale model, and asked him to show us how it was done, it came out, from another mine employee, that he purposely mashed his hand in order to retire early, and get a large settlement from workers comp. The guy dropped the suit, and never showed up for the test. However, all it would take, would be a bolt or screw to break, to cause something similar, and you would have a similar suit.
In guns, though, we are fortunate enough to not have critical fasteners. The worst we have, (as far as stripping or breaking), are the small ones, for scopes, etc. I always wondered what would happen if a stock bolt broke, when fired, and the gun came back and injured someone. That is a possibility for some designs. The only other place, would be barrel nuts or threads. Here, the military has a torque limit on the AR designs.
DG,
I got one of the Wheeler FAT drivers on impulse when I found it on sale at the local Gander Mountain. To my pleasant surprise, it did come with a three-point calibration sheet. That sheet is currently hiding in my files somewhere, but IIRC, it was just about dead on at 30 in-lbs (30.05 in-lbs?), and was off something close to one in-lb near the ends of the range.
They guarantee ±2 lbs on the package. Not ±2 in-lbs; just ±2 lbs. So I don't know what that actually means. It may be a typo, but I gather Wheeler is a lawyer, so it also may be an intentional warranty wiggle phrase. I have no way to know which. The tool seems to work OK, though I'll probably recheck its calibration from time to time.
I got one of the Wheeler FAT drivers on impulse when I found it on sale at the local Gander Mountain. To my pleasant surprise, it did come with a three-point calibration sheet. That sheet is currently hiding in my files somewhere, but IIRC, it was just about dead on at 30 in-lbs (30.05 in-lbs?), and was off something close to one in-lb near the ends of the range.
They guarantee ±2 lbs on the package. Not ±2 in-lbs; just ±2 lbs. So I don't know what that actually means. It may be a typo, but I gather Wheeler is a lawyer, so it also may be an intentional warranty wiggle phrase. I have no way to know which. The tool seems to work OK, though I'll probably recheck its calibration from time to time.
Dixie Gunsmithing
Moderator Emeritus
Unclenick, I don't have the Wheeler, but do have the Weaver, and I don't recall it having a calibration sheet with it. I figured they would be the same. I have one of the older Harbor Freight drivers, too, and I don't recall it having one, but I think their wrenches do.
All the gun driver types work on the basis of spring tension, holding two toothed discs together. The more you tighten the driver adjustment, the spring compresses, and makes it so it takes more torque to make the two discs part, and slip. Since they use coil springs, I'd say they are kept are close in tolerance between each, no less than +/-2 pounds, is about all they could hope for. To get it more exact, it would take a internal calibration adjustment and using a torque meter to adjust it. From what I can tell, these are not adjustable, as far as calibration goes. They figure the poundage off the amount of spring compression.
All the gun driver types work on the basis of spring tension, holding two toothed discs together. The more you tighten the driver adjustment, the spring compresses, and makes it so it takes more torque to make the two discs part, and slip. Since they use coil springs, I'd say they are kept are close in tolerance between each, no less than +/-2 pounds, is about all they could hope for. To get it more exact, it would take a internal calibration adjustment and using a torque meter to adjust it. From what I can tell, these are not adjustable, as far as calibration goes. They figure the poundage off the amount of spring compression.
I have the wheeler as well. It has been fine, purchased new. Having used torque wrenches in other job types, i learned that taking care of them goes a long way to helping them stay calibrated.
Clearly, not dropping them is one. It is kept turned all the way down. I set it to use it, always going up from a lower setting, so if i have to do something that requires a lower setting than it is currently at, i go down past where i need it, and come back up to the setting i need. When finished, i turn it all the way down before storing it. I do not use it to break loose screws, only to set tightness.
I had a customer come in with a shotgun that the stock broke while shooting it. A benelli or beretta semiauto, it had the recoil spring in a tube in the stock. The tube broke flush with the rear of the receiver when he was firing it.
It beat him up a little, but nothing major. A bruise on his face, some good scratching of the hand where the back end of the receiver was ripping itself out of his hand, worked on the fingers a bit.
Clearly, not dropping them is one. It is kept turned all the way down. I set it to use it, always going up from a lower setting, so if i have to do something that requires a lower setting than it is currently at, i go down past where i need it, and come back up to the setting i need. When finished, i turn it all the way down before storing it. I do not use it to break loose screws, only to set tightness.
I had a customer come in with a shotgun that the stock broke while shooting it. A benelli or beretta semiauto, it had the recoil spring in a tube in the stock. The tube broke flush with the rear of the receiver when he was firing it.
It beat him up a little, but nothing major. A bruise on his face, some good scratching of the hand where the back end of the receiver was ripping itself out of his hand, worked on the fingers a bit.
johnwilliamson062
Moderator
You know, they still make beam style orque wrenches that will hold their calibration almost infinitely. At least until they are visibly damaged. Having some limited exposure to click type torque wrenches used in aerospace, I would never buy one for personal use. Too much maintenance and not that reliable even when calibrated.
FrankenMauser
New member
johnwilliamson062, I would have to disagree, based on my experience.
Click-type wrenches are very reliable, provided you don't abuse them (the same goes for almost any tool).
The Snap-On wrenches (nothing special, just standard Snap-On items) that we used on the helicopters were often calibrated to deviations less than +/-1%. Frequently it would be less than +1% / -0%.
Whether you're dealing with a 96 in-lb torque that's going to be at, or not more than 0.96 in-lb over the target, or a 4800 in-lb* torque that will be within 4 ft-lb of the target, that's pretty danged repeatable and reliable.
*(Even our 400+ ft-lb torque values were specified and had to be documented in in-lb. The 1,200, 2,400, 4,800, 9,120 in-lb [760 lb-ft] incremental torque on one of the rotorhead bolts always raised some eyebrows and caused some head-scratching for the mathematically challenged.)
Click-type wrenches are very reliable, provided you don't abuse them (the same goes for almost any tool).
The Snap-On wrenches (nothing special, just standard Snap-On items) that we used on the helicopters were often calibrated to deviations less than +/-1%. Frequently it would be less than +1% / -0%.
Whether you're dealing with a 96 in-lb torque that's going to be at, or not more than 0.96 in-lb over the target, or a 4800 in-lb* torque that will be within 4 ft-lb of the target, that's pretty danged repeatable and reliable.
*(Even our 400+ ft-lb torque values were specified and had to be documented in in-lb. The 1,200, 2,400, 4,800, 9,120 in-lb [760 lb-ft] incremental torque on one of the rotorhead bolts always raised some eyebrows and caused some head-scratching for the mathematically challenged.)
Dixie Gunsmithing
Moderator Emeritus
Gunfixr, It's according to the person they are, and the amount of damage, whether they would sue, but that person had a case. However, I doubt it would have been of any large amount, as for damages. Maybe an ER bill, and time off work, etc. Now, if it had inflicted permanent damage, I could see a whopper of a suit. As long as you didn't work on that part of the gun, beforehand, you're in the clear, but the factory isn't.
I've tried to think of the scenarios in firearms, that would cause us to get sued, as Gunsmiths, and barrel work would be the worst. Especially barrels that burst, such as shotgun modifications, etc. I've always been very particular on them.
I could see a stock bolt biting us in the rear, though. The problem is, that where the stock is something compressible, such as wood or plastic, the bolt can loosen, over time, as I've seen that happen. Then, over continued movement, over a loose joint, it could break. On top of that, recoil spring tubes have always been weak, like on the Winchester model 50 and 59.
When reading both the Winchester and Remington factory service manuals, which are the most detailed, neither gave a torque value for that bolt, on any model. I'm not sure whether a military manual would have it or not, as I've never looked. There are torque values listed for whatever thread it would be, but would they work in the real world, on guns?
I've tried to think of the scenarios in firearms, that would cause us to get sued, as Gunsmiths, and barrel work would be the worst. Especially barrels that burst, such as shotgun modifications, etc. I've always been very particular on them.
I could see a stock bolt biting us in the rear, though. The problem is, that where the stock is something compressible, such as wood or plastic, the bolt can loosen, over time, as I've seen that happen. Then, over continued movement, over a loose joint, it could break. On top of that, recoil spring tubes have always been weak, like on the Winchester model 50 and 59.
When reading both the Winchester and Remington factory service manuals, which are the most detailed, neither gave a torque value for that bolt, on any model. I'm not sure whether a military manual would have it or not, as I've never looked. There are torque values listed for whatever thread it would be, but would they work in the real world, on guns?