340 ftlb torque for WDH bolts holy cow

[TheWolfPaq82]

I've got a 60" piece of drill pipe that fits over my big wrench. I haven't found a nut yet that I couldn't break loose or twist the shank off of.

[Walholler]

The only true way to properly torque a bolt or nut is with a calibrated torque wrench. Using a torque wrench that has not been calibrated by a certified lab, you do not know if the torque wrench is breaking at the set degree of torque or not. If your going to use any of the methods described above, you might as well just tighten with a breaker bar and length of cheater pipe.

[TheWolfPaq82]

Originally Posted by Walholler

The only true way to properly torque a bolt or nut is with a calibrated torque wrench. Using a torque wrench that has not been calibrated by a certified lab, you do not know if the torque wrench is breaking at the set degree of torque or not. If your going to use any of the methods described above, you might as well just tighten with a breaker bar and length of cheater pipe.

Yep ! X2

[NJKris]

Well, I have to respectfully disagree on this one. Simple physics. A force vector applied to a moment arm at 90 degrees at the proper distance from the center of the socket/nut IS the correct torque, no calibration or torque wrench required. Once that nut stops turning and you are sure of the proper distance given the applied weight, torque is reached, so long as the force applied is straight down, not at an angle, meaning you may have to reset the socket on the nut to do so.

I've met a lot of mechanics, and NONE have torque wrenches that go to 350 ft.lbs., therefore it's good to know how to improvise.

[babock]

Originally Posted by NJKris

Well, I have to respectfully disagree on this one. Simple physics. A force vector applied to a moment arm at 90 degrees at the proper distance from the center of the socket/nut IS the correct torque, no calibration or torque wrench required. Once that nut stops turning and you are sure of the proper distance given the applied weight, torque is reached, so long as the force applied is straight down, not at an angle, meaning you may have to reset the socket on the nut to do so.

I've met a lot of mechanics, and NONE have torque wrenches that go to 350 ft.lbs., therefore it's good to know how to improvise.

Yep X2

[aeblank]

Originally Posted by babock

Yep X2

X3.

Beyond that, +/- 10% is PLENTY accurate enough. Overall, tight AF covers it.

[ard58]

Originally Posted by NJKris

Well, I have to respectfully disagree on this one. Simple physics. A force vector applied to a moment arm at 90 degrees at the proper distance from the center of the socket/nut IS the correct torque, no calibration or torque wrench required. Once that nut stops turning and you are sure of the proper distance given the applied weight, torque is reached, so long as the force applied is straight down, not at an angle, meaning you may have to reset the socket on the nut to do so.

I've met a lot of mechanics, and NONE have torque wrenches that go to 350 ft.lbs., therefore it's good to know how to improvise.

You don't know any diesel mechanics, or heavy machine mechanic's.

[Bluepill]

Using a tongue weight scale, I set the weight by distributing loads in the trailer. Lower the trailer onto the wrench at 12" and lower the coupler:

[Donald 1]

My instructions said torque 150 ft lbs plus 1/4 turn on the nut

[rockfordroo]

Originally Posted by ard58

Where did you come up with this? I would venture to say you have never pulled a 3/4' torque wrench to 300#'s. 3/4" torque wrench is approx. 36" in length. You have to really pull on that long of a wrench to get it to click when set a 300#'s. I would bet that if there's someone out there that has worked on diesel engines would agree. You wont get 340#'s of torque on an 18" wrench.

I didn't say I pulled on it. I stood on it. And as mentioned, I only needed 180 lbs to get 240 ft-lbs with an 18" wrench.

And I guarantee you that if you stand a 226 lb guy on the end of an 18" wrench, you will have 340 ft-lbs. Re-read NJKris' post.

[rockfordroo]

Originally Posted by NJKris

Well, I have to respectfully disagree on this one. Simple physics. A force vector applied to a moment arm at 90 degrees at the proper distance from the center of the socket/nut IS the correct torque, no calibration or torque wrench required. Once that nut stops turning and you are sure of the proper distance given the applied weight, torque is reached, so long as the force applied is straight down, not at an angle, meaning you may have to reset the socket on the nut to do so.

I've met a lot of mechanics, and NONE have torque wrenches that go to 350 ft.lbs., therefore it's good to know how to improvise.

Originally Posted by ard58

You don't know any diesel mechanics, or heavy machine mechanic's.

What NJKris said is TRUE. However, the only way to do this without a torque wrench is to apply a known weight downwards on a wrench of known length. This is relatively easy to do on a nut on a horizontal bolt like on an Equal-i-zer hitch. You can do it on a wheel nut, too.

BUT - Since most diesel mechanics and machine mechanics can't apply a known weight downward on, say, a head bolt, or some nut or bolt in an engine bay, they NEED to use a torque wrench. Also, when they have multiple torque values to deal with, it's a lot easier to use a torque wrench than to search for the right combination of wrench length and mechanic weight! - LOL

But just because they use torque wrenches doesn't mean what we are discussing doesn't work.

[Walholler]

I would like to know how you can determine the actual torque your applying if you do not use a calibrated wrench. Lets say the nut or bolt is by design able to with stand 350 ft. lbs. of torque or 4200 inch lbs., along comes grease monkey Jim with a 3/4 inch breaker bar and stands on the bar until he determines it is tight enough. Now the question is, is his torque at 300 ft. lbs., 350 ft. lbs. or has he over torqued and cracked the nut or bolt. Time will tell when your towing down the highway and the trailer departs the tow vehicle because a jack legged mechanic that has no ideal of what torque he actually applied fixed your vehicle or travel trailer. I realize that we are only talking about RV's, but I worked in the aviation field all my life and can tell you about the correct use of a torque wrench. If I had caught anyone applying torque the way some has suggested here, I would have kicked his ass up to his shoulders. At 280 lbs. and 6'4", I am big enough to do it.

[NJKris]

Aviation Electrician here, and no stranger to a torque wrench either. To be precise, if my earlier explanation was not clear, A car mechanic applies a force of 800 N to a wrench to loosen a bolt. She applies the force perpendicular to the arm of the wrench. The distance from the bolt to her hand is 0.40 m. What is the magnitude of the torque applied?
Answer: The angle between the moment arm (the arm of the wrench) and the force is 90°, and sin 90° = 1. The magnitude of the torque is 320 N∙m. In our case, we are using foot pounds, not Newton meters, which would be the metric equivalent. Therefore, using Walholler's stature at 280 lbs, and desiring a torque of 340 ft.lbs, he would have to apply his weight on the wrench at 1.2 feet from the nut, or solving for inches, 14.4 inches away from the center of the socket/nut if you prefer. Not hop up and down on it, just smoothly applying the weight. Torque wrenches are simply a tool to enable you to apply the same force, in situations where you might not be able to apply force in this way, such as if swinging the wrench in a horizontal plane, obviously you would not be able to apply the force accurately.

[itat]

Originally Posted by Walholler

I would like to know how you can determine the actual torque your applying if you do not use a calibrated wrench. Lets say the nut or bolt is by design able to with stand 350 ft. lbs. of torque or 4200 inch lbs., along comes grease monkey Jim with a 3/4 inch breaker bar and stands on the bar until he determines it is tight enough. Now the question is, is his torque at 300 ft. lbs., 350 ft. lbs. or has he over torqued and cracked the nut or bolt. Time will tell when your towing down the highway and the trailer departs the tow vehicle because a jack legged mechanic that has no ideal of what torque he actually applied fixed your vehicle or travel trailer. I realize that we are only talking about RV's, but I worked in the aviation field all my life and can tell you about the correct use of a torque wrench. If I had caught anyone applying torque the way some has suggested here, I would have kicked his ass up to his shoulders. At 280 lbs. and 6'4", I am big enough to do it.

We’re “shade tree mechanics” without expensive torque wrenches. It’s not precision for sure, but if you want to be more certain, stand on the breaker bar /wrench handle as rockfordroo and NJKris said (or an extension pipe) further than the distance that the formula gives you. We’re looking for at least X ft.-lbs, not exactly X ft.-lbs.

[NJKris]

If I had caught anyone applying torque the way some has suggested here, I would have kicked his ass up to his shoulders. At 280 lbs. and 6'4", I am big enough to do it.

Obviously, from a QC standpoint in the aviation field, this would not be allowable or practical. I used to have a QC inspector confirm the torque wrench reading. But for an alternative way of applying the proper torque to a hitch ball nut in the absence of having your own 350 dollar torque wrench you will probably only use once for this application, this is one way of doing it.

[Scrapper]

Originally Posted by NJKris

Well, I have to respectfully disagree on this one. Simple physics. A force vector applied to a moment arm at 90 degrees at the proper distance from the center of the socket/nut IS the correct torque, no calibration or torque wrench required. Once that nut stops turning and you are sure of the proper distance given the applied weight, torque is reached, so long as the force applied is straight down, not at an angle, meaning you may have to reset the socket on the nut to do so.

I've met a lot of mechanics, and NONE have torque wrenches that go to 350 ft.lbs., therefore it's good to know how to improvise.

I have to disagree here. The company I worked for had a torque wrench that would go to 1000 ft lbs. Total length of the wrench was 10".




Oh, I forgot to mention it was a hydraulic torque wrench.

[Iwannacamp]

If y’all ever want to do this without the Rube Goldberg experiments and want to torque the bolt/nut...go to any truck or truck tire shop. They have real torque wrenches.

[Iwannacamp]

Originally Posted by Scrapper

I have to disagree here. The company I worked for had a torque wrench that would go to 1000 ft lbs. Total length of the wrench was 10".




Oh, I forgot to mention it was a hydraulic torque wrench.

Or maybe that part was a multiplier.

I would try to respectfully say that if a 300# torque requirement fastener was actually torqued to 350# of torque and it broke??? one would look for a defective fastener. Notice no one mentioned torque to yield fasteners in my post.

However I do know other posters were just using an example. Camp on.

[rockfordroo]

Maybe this will help the naysayers. They're basically calibrating their torque wrench by measuring off a distance and hanging a weight (same as standing on it if you know your weight).

https://www.wikihow.com/Calibrate-a-Torque-Wrench

Distance x weight = torque

[andymil]

What do you think a torque wrench is telling you?

Let’s say that a torque wrench has a moment arm of 12 inches and is set to 100 ft-lbs. The wrench clicks when you have applied 100 lbs of force to a point 12 inches from the center of rotation. If you don’t apply more force, the nut or bolt stops turning and is properly tightened to 100 ft-lbs.

If you apply a force of 100 lbs to any wrench at a point 12 inches from the center of rotation, it will be applying 100 ft-lbs of torque to the fastener.

If you disagree with this, then don’t do it!