# What's a torque wrench?

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• posted on May 19, 2004, 7:21 am

Claudia wrote:

Now that you have the right amount, set the wrench to 10 foot-pounds and pull, you should hear a click. If it does click, move it up in steps and keep listening for the click. If you don't hear the click at 10 pound or 20 pound setings, then the torque wrench is most likely ruined and not functioning. Just pull hard on it and you will get the torque close enough.
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<%-name%>
• posted on May 19, 2004, 2:37 am
says...

bolt to

to
it must be. even the nut on the back axle of a volkswagon is only like 180 foot pounds or something and you need serious power tools or a 10' steel rod to get that.
randy
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<%-name%>
• posted on May 22, 2004, 3:10 am
she's talking about a mower blade, which oughta be pretty heavy torque.
500 inch pounds -- that would be 500 divided by 12, which is about 45, or so. Not near a calculator. 45 is believable for a mower blade bolt.
Briggs tends to be on with a 9/16 bolt head (what's that, like 3/8-16?) and so that's doable.
Tecumseh tend to be a larger nut (15/16?) and that might go more like 75 ft pounds, my guess.
--

Christopher A. Young
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<%-name%>
• posted on May 19, 2004, 2:11 am
Check you specs again. 400 to 600 ft-lbs torque will shear off most any bolt you'll find in a lawn mower. Is it 400 in-lbs?
RB
Claudia wrote:

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<%-name%>
• posted on May 19, 2004, 2:33 am
| Check you specs again. 400 to 600 ft-lbs torque will shear off most any | bolt you'll find in a lawn mower. Is it 400 in-lbs? | | RB | | Claudia wrote: | > Actually I know what it is, but I am not sure I am using it correctly. | > | > I replaced a blade on my lawn mower, and I was trying to tighten the bolt to | > spec, which is between 400 and 600 ft lbs. Well, I set my torque wrench to | > 500 ft lbs, and I was hoping to hear the "click" that tells me I got to | > destination. But it's been a while since I used a torque wrench, and I am | > not sure what I should be hearing anymore. Can you help? When I try to | > give it another 1/4 turn I hear something, but it's not a full blown click. | > Does this make sense? Yet, I don't want to go any further and overtighten | > or even break something | > | > For what it's worth, I was able to unscrew the bolt with the same setting on | > the torque wrench. I am thinking that maybe this tells me that if I exerted | > more or less the same force to unscrew it as I am in tightening the bolt ... | > I should be okay. | > | > Any help is appreciated. | > | > Claudia | > | >
Yes, it is inch lbs. See my response to Java Man if interested in this saga. :)
thanks
Claudia
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<%-name%>
• posted on May 19, 2004, 3:51 am
Claudia wrote:

the bolt that holds on the blade on a lawnmower is nothing close to 500 lbs... its more like 80-100 ft. lbs... if you hear a noise when cranking it up to 500 ft. lbs. its probably the bolt breaking........
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<%-name%>
• posted on May 19, 2004, 5:18 am

500 ft-lbs doesn't sound that unbelievable. That's about the same torque as an axle bolt on a car.
80-100 ft-lbs is like the torque on a car's wheel's nut; that's not enough for the blade of a lawnmower!
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<%-name%>
• posted on May 19, 2004, 7:28 am
Scrutinizer wrote:>80-100 ft-lbs is like the torque on a car's wheel's nut; that's not enough

Sure it is. More than enough. Tom Someday, it'll all be over....
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<%-name%>
• posted on May 19, 2004, 1:01 pm
TCS wrote:

well read the original posters added on comments that he/she looked at the scale wrong on the wrench and it was 500 in.lbs of torque.... well at 500/12 = 41.6 lbs. of torque that is why his wrench clicked as he easily reached the set torque... and i still stand by the statement of 500 ft. lbs. of torque on a lawmower is way too much.... the flywheel bolts on cars is only set at about 150 lbs. of torque... and that's pretty tight....
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<%-name%>
• posted on May 19, 2004, 1:45 pm

Not only that... the bolts that hold mower blades in place aren't all that big. It's _physically_impossible_ to tighten one to 500 ft-lbs, because the bolt would shear _long_ before it reached that torque.
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<%-name%>
• posted on May 19, 2004, 1:43 pm

Yes, it does. 500 in-lbs is believable, but 500 ft-lbs is not.

No, it's about two to three times the torque on *anything* on a car.

Nonsense. That's too much for a lawnmower blade, actually: the bolts are smaller than wheel lugs on a car, and made of softer steel besides. For mower blades, 40-60 ft-lbs is more like it; the spec on my John Deere STX-38 is 55, for example.
That may be a bit high for cars with aluminum-alloy wheels, too...
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<%-name%>
• posted on May 19, 2004, 7:14 am
Claudia wrote:

No way is the spec anywhere near 400 foot pounds. With a 4 foot handle, you would still need to exert a 100 pound force. You would need to be a monster woman to get 400 foot pounds with a regular 1/2" torque wrench with an 18" handle. The nut on the mower blade should tightened to something like 40-50 foot-pounds.
To answer your question most just give a little "click" and that tells you to stop pulling. en you don't pull any harder. You don't need a torque wrench anyway. Take a 50 pound sack of anything and lift it with one hand. If you can, use a 12 inch handled 1/2" socket wrench on that nut and pull it as hard as you can with one hand. If you can't lift a sack with one hand, then use two on the wrench.
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<%-name%>
• posted on May 19, 2004, 7:39 am
That's pretty high... 400 ft lbs is a lot....... It will be a click....back off after you think you hear the click and pull it up again slowly to make sure it clicked
Terry

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