Home Forums Hunting & Shooting Hunting Optics Which torque wrench is better: Wheeler Fat Handle or Weaver?

Ours get calibrated/certified once per year, and checked on calibrated fixtures before each use. When you check one out, you confirm that the setting you expect to use is accurate. Then after the job, you can double check.

I've seen several fail including Snap-On.

Yeah. You're right, I'm wrong.

The only way to ensure a fastener is torqued correctly and meets a very high standard (FAA requirements) is to check it on a calibrated fixture, for that torque setting, before and after each and every use.

I'm just guessing at this chit.

It is EXTREMELY important to understand the difference between corporations which need to follow, say, ISO 9001 or whatever else set of procedures such corporations want (or must) to follow, and individual users of torque tools. In order to pass audits, corporations must renew stickers attached to tools every year (or two years, or whatever), even if these tools were not used at all. Which means doing calibrations, certifications, etc. no matter if it makes technical or practical sense at all. It's all about paperwork and formal compliance with regulations, and some of these regulations are nothing but waste of time. Had a lot of experience with all that stuff...

On the other hand, individuals have no need whatsoever to do the same things, individuals are not obligated to follow ISO procedures, have any "approved" type of paperwork, and can afford, which is really great, just use common sense. Which often does not dictate any need for annual calibration if torque tools are not used a lot. And because torque tools for firearms applications, limited to individuals, are hand tools, which means they are, very likely, not being used a lot (who, realistically, not being a busy gunsmith or somebody involved in manufacturing, is using torque tool 1,000s times a year?), all this obsession with need for calibration of torque tools, owned by individuals for their private use, looks a bit funny to me. The only practical case for calibration of privately owned torque tool is just to make sure that such tool is actually matching claimed torque output, if tool owner has a justified suspicion that it may be an issue.

I use an expensive Norbar 1/4" torque wrench which is accurate to 4%, only because I've had it for years. I can't see why either the Wheeler or Weaver is just as good as any out there for scope ring torqueing. It's not a critical application. Lubricating the screws is important though as dry screws will give high readings when they not properly torqued.

I have two Nasco fixed torque drivers: a 22"lb and a 40"lb. These two cover most of my needs, the smaller 22 for tightening scope rings and the 40 for attaching rings to bases and torqueing receiver action screws. The drivers seem well made and even have a piece of paper certifying their accuracy. I suppose over time, the settings can gradually change and thus benefit from recalibration, but I haven't bothered to do so.

I also own an adjustable torque driver from Northern Tool. It seems to work OK, but I can't speak to its accuracy or repeatability.

Finally......somebody said it.......


Casey

If one lubes the threads of a fastener then the torque needs to be decreased. If you lube the threads on a ring-cap screw and tighten it to the specs given by the manufacturer you will be over-torquing the screw. I researched this subject after it was mentioned in a thread. If you Google it, you can find tables that give you dry-torque values and the corresponding lubed-torque values.

*

I agree totally with the above post. Certain uses don't require perpetual calibration.
My expectation, more than actual accurate numbers within 0.05% of claimed, is that whatever setting I pick for action torquing remains accurate the next time I take it apart and put it back one. I guess if you use it 1000 times a year it may need to be recalibrated.
I may be wrong, as I have been that one time in my life :), but ISO 9001 means certification of accuracy and standarization, so that someone in Japan can get repeatable results with someone in the Polynesian islands and someone in Subsaharan Africa. Does not mean that not having ISO9001 is bad, it just means you can't be totally sure.

By the way, I think 4th poit offer is not to criticize Wheeler, Weaver, Brownells or any other brand, just a scientific test and offer to dispel myth, provide information and see what they are all about.
It is up to the consumer to decide what they will purchase, or not, based on the findings.

tag

That's right Sponxx.

I just offered to test torque wrenches for people since I have the equipment handy and am interested in the results. The owners get data for their wrench, and the rest of us get to see how the different makes/models compare. Maybe the Weaver and Wheeler are accurate and repeatable. Maybe they aren't. The only way we'll know is to test them. Same goes for a $180 wrench. Let's see how they do.

Nobody in this thread ever said that ISO certification is needed for a wrench for their scope mounting. I just made a genuine offer to test a wrench for some people and others rant about ISO. Wow! Now my feelers are hurt! Can I file a report with Rick?

I have the equipment to test the wrenches. On calibrated equipment, in an ISO certified facility. This just gives us a little confidence in the data we get. Rather than some unknown, uncalibrated measurement device.

Jason

Or we could just trust that Wanda had a good day in the factory and actually did her job calibrating our favorite brand of torque wrench. Or is it Pham, who has never seen a rifle or scope in her life? Who cares if its off by 10%, right? 10 minutes until lunch.

We've had all brands of torque wrenches schit-the-bed at work. Latest one for me was a 1/4" Snap-On. It was off by 20%.

On the other hand, I've seen several 1/2" wrenches from Harbor Freight do just fine. Good enough for casual use in the backyard garage for things like lug nuts. But its easy for us to check them periodically. I'd be more selective if I was rebuilding an engine though.

So if you're shopping for a wrench to use for scope mounting, you must be concerned with accuracy and repeatability. Especially for such dinky hardware. Too loose, and your rings/mounts may detach. Too tight, and you could crush a scope tube or affect tracking. Some say that they don't care if its accurate, just repeatable. Well, how do you know this?

I ask this because I've had several fish scales, kitchen scales, bathroom scales, etc. and they are not that accurate or repeatable. What makes someone think that a torque wrench is any different? Wanda or Pham did an uber-job that day, just for you!? And how can you make such a statement without data to back it up?

Paying more money might help ensure accuracy and repeatability.

Or just test them and see how they do. I'd rather do this.

J

You're quite correct. I always thought it was the other way around but Googled the tables as you suggested and about a 25% reduction in torque values should be applied to oiled screws.

Thanks for the information.

Good on you for the offer, 4th point. I'm interested in results myself. My torque wrench of choice came with a certificate of calibration. Could it be wrong? Yes. In fairness though, I have no more reason to believe in your ability to check these instruments than Wanda or Pham.

Wheeler FAT and Weaver adjustable torque screwdrivers accuracy rely on linear characteristics of the spring, which loads torque limiting clutch. They have identical principal design, with Weaver having a bit longer spring, which, both theoretically and practically, is a better way to ensure tool accuracy in mass production (1) and to make adjustment scale a bit longer for better readability by the user (2).

Initial adjustment (or calibration) is done at the factory for only ONE specific torque setting, typically the one in the middle of torque adjustment range. Accuracy within the whole adjustment range then depends upon linear characteristics of the spring, and nothing can be done about it. Typically, spring rate is found to be linear and may be reliably "synchronized" with adjustment scale if active spring load is between 20% and 80% of the maximum spring load. Which means that adjustable torque screwdriver may have decent accuracy if it is used for outputting the torque with adjustment ratio of 1 to 4 (from 20% to 80%) or so.

Wheeler FAT has an adjustment ratio of 10 to 60 inch-lbs. (1 to 6 ratio), Weaver has theoretically less favorable adjustment ratio of 10 inch-lbs. to 80 inch-lbs. ( 1 to 8 ratio), but has longer scale and slightly better scale resolution than FAT.

In my opinion, Weaver branded adjustable torque screwdriver supplied by Da-Jiun Co. from Taiwan is overall better made than Wheeler branded tool made in China (not sure which company in China makes this one).

Harbor Freight (from China) wrench with 20 to 200 inch-lbs. torque adjustment provides ratio of 1:10, which is really "pushing it" above proven technology,so do not expect any miracles of accuracy at low and high torque settings with that HF product.

Initial factory calibration to a single torque setting in the middle of the adjustment range, which is likely matches 45-50% of the spring load, is done with use of shim washers, which are typically custom made and installed during tool assembly at the factory.

Repeatability, in general, is ensured by the quality of parts used for assembly. If parts of the torque limiting clutch and spring itself are of high quality, means these parts are made from good materials/properly heat treated, then tool parts wear will be minimized to acceptable levels and repeatability will be preserved over considerable period of time. Repeatability also depends how well the tools user can see the scale markings and the scale pointer, which is, naturally, a subjective factor.

To summarize - adjustable torque screwdrivers like Wheeler FAT and Weaver can be re-calibrated, but only for ONE specific torque setting within the whole adjustment range. However, such re-calibration requires the use of the custom parts (shim washers), which are not likely to be easily obtainable by the individual owner of the tool or even by the test lab. This is because these shim washers, being of proprietary design, are not likely to be available from industrial supply companies like McMaster Carr and others.

These adjustable screwdrivers can be, of course, also checked (verified) for various torque settings within the range. If results of verification shows that torque output matches adjustment scale, say, in the middle of the range and does not match the scale at both ends of the same scale within claimed deviation, say, of no more than +/-6%, nothing can be done about it.

If parts used for torque limiting mechanism lack quality, repeatability will go to hell after some relatively short use, and nothing can be done about it.

And testing, say, of 10 adjustable screwdrivers, either Wheeler FAT or Wheeler, is not going to determine that, say, the other 100,000 of them are good or not, these tools are massed produced in Asia, where quality is typically hit or miss depending upon specific batch of tools. BTW, this happens not just with Asia made products, I've seen it done by some U.S. suppliers as well, but, statistically, on a lesser scale.

Yes, you can send your particular tool to test lab, but results of such test may not give sufficient info to determine which of the two tool brands is "better". In addition, results of such test may not help at all to fix potential issues with accuracy and repeatability, if any are found.

In my opinion, if testing is done without having an option to fix potential issues, it's useless waste of time. To make everything more practical and less stressful, just buy quality tools.

You're making it way too complicated. If you can tighten a nut with a wrench and read a display, you could do it. That is, to read the actual torque value vs the torque wrench.

I don't plan to re-cal anyone's wrench for them though.

Yes sir, anytime!

Very honest answer of yours.

So, let's assume you get somebody's torque tool, use your company's equipment to find out that this somebody's tool is, unfortunately, no good, and give the bad news to the owner of the tool.

Then, what is, in your opinion, a type of corrective action which the owner of the tool can implement next, technically speaking? For example, tool owner may complain to the tool seller that torque tool is no good and demand refund or replacement, but unless tool owner gets some kind of paperwork from you to back up the claim, tool seller is likely going to disregard the claim. Will you be providing industry standard certificate of calibration per ISO 6789 to the tool owner?

Re-setting the tool if it reads incorrectly would void the warranty.

I don't know what the warranty is for the Wheeler or Weaver. Others like the Wiha mentioned earlier will have a full tool warranty. I suspect that cheap wrenches would just get pitched in the trash if they were really bad.

Post the ISO 6789 standard and let's look it over.

Jason