click torques wrenchs

[WHY]

Anyone out there ever buy or use a "harbor freight" 1/2 inch torque wrench,---- are they worth buying ???

Tony

 

[Stan V]

Yes, and for the money they can't be beat, I also own an inch torque wrench which I bought from an autozone automotive supply store, 50 bucks but really great quality needed where the lower torques are required.

 

[bryancobb]

Here's my findings. They work! The click at a consistent point every time! The problem is...whether or not the torque markings/numbers are correctly located are hit-or-miss.

I use an old timey "shaft-flexes" type to verify the setting and don't pay any attention to the numbers. Once it's set by the old timey one, I like the convenience oof NOT having to observe anything except the"CLICK."

 

[scottessex]

We have to have ours calibrated every 6 months. Don't ever drop it! and store it at about 20% of the lower range.

 

[WHY]

Thanks guys

Will probably get one next week, need a torque wrench to start final assembly of Weber 750.

Tony

 

[cbonnerup]

We have to have ours calibrated every 6 months. Don't ever drop it! and store it at about 20% of the lower range.

Click-type torque wrenches should be stored with the adjustment handle backed all the way off. One does not store a calibrated spring in compression.

Also should never be oiled. If it sticks or stutters when adjusting it's either time for a new one (if Harbor Freight) or a re-cal (Craftsman, Matco, etc).

My experience and opinion - results may vary.

Chris

 

[500e]

Click-type torque wrenches should be stored with the adjustment handle backed all the way off. One does not store a calibrated spring in compression.

That was what I was taught as well

 

[scottessex]

That is what I was taught, but the PMET (precision measuring equipment and tooling)
department said not to back them off all the way..... Looks like further investigation is in order.

 

[bryancobb]

Some of them have parts inside that can fall out of position if you take ALL the tension off.
For example, the spring must be seated perfectly at both ends for it to indicate the correct torque. If you loosen all the way when stored, the spring can move. Then next time you use it, you have no way of knowing if the spring jumped back where it's suppose to be or if you are squeezing it in it's dislocated position.

 

[cbonnerup]

Hmmmmm, a torque wrench thread!
Tony, either go with mfgs. recommendations (if a personal purchase) or with your organizations specs if applicable.
Or buy one of these: no springs per se.

http://www.sears.com/craftsman-electronic-torque-wrench-1-2-in-drive/p-00947712000P

Still needs occasional calibration depending upon use and criticality.

Chris

 

[NoWingsAttached]

That is what I was taught, but the PMET (precision measuring equipment and tooling)
department said not to back them off all the way..... Looks like further investigation is in order.

That actually makes sense, to store it under just enough tension to keep it from being completely relaxed. I once stored mine under high tension and the next time I went to use, months later, it was srap metal. I was also told to never use it to remove nuts and ignored that advice, so maybe that is what ruined it?

I forgot my pointer type the other day when I went out to fix the Arrow, and decided to try my hand at "feeling" the nuts, and using degrees turned to sequence the nuts on the studs.

I checked everything with the torque wrench yesterday, and could not detect any variation from one nut to the next, and they were all dead-on 26 fp.

Where the Torque wrench is really necessary for me is not the comfortable nuts to snug up, but rather those heavy-duty things with the big nuts and torques exceeding routine tightness.

 

[500e]

I have a beam wrench that was my fathers, I am 70+ the old wrench is still accurate compared with my clicker one which is only 10 years old the clicker is calibrated on a regular basis& has usually drifted after a year or 2, the beam checked in 10 pound increments against the recently call one is within a less than a pound error to its max 80lb

 

[karlbamforth]

I checked everything with the torque wrench yesterday, and could not detect any variation from one nut to the next, and they were all dead-on 26 fp.

Just out of interest. How did you check that ?

I'm trying to work out how you checked it without first releasing the torque and then retightening them.

 

[WHY]

Question on torques specs

If you are setting a bolt with a thread locker such as "blue loctite" would this be considered as a "lubed bolt" when chosing the torque spec ?????

Tony

 

[dragonflyerthom]

Great question Tony. Waiting on the answer here in good ol Arkansas.

 

[JEFF TIPTON]

http://www.practicalmachinist.com/vb/general/torque-specs-locktite-204146/

Actually I did call Locktite and spoke to one of their engineers. All he would tell me (and I think that he actually knew the number I wanted but wasn't allowed to say) was the usual formula T=kXdXp. But without an accurate k, this is not much help.

If I can't get a real world experience answer here, I will have to construct a test. Torque a dry nut to spec and measure bolt stretch, apply Locktite and see what torque produces the same stretch. Just trying to see if any one else had travelled this road before. Want to get this right as the fasteners in question hold an engine on an airplane!

Now the really interesting part. A Locktite rep saw this post and contacted me. (Thanks Lindsey) Very interesting long chat. He confirmed that a test setup would be best but mentioned that the low viscosity Locktite products were deliberately engineered not to be too lubricating so as to not screw up published torque values. He said that they behave much like a very light SAE 10 machine oil with a k value of around 0.15 plus or minus. He said that the more viscous products are more lubricating. He said that if the common low viscosity products are applied on the threads only, a torque reduction of about 10 -12 % is about right. The thicker stuff that I am contemplating is between 15 and 20 %. (This is from dry bare steel, not plated steel.) He also mentioned the fact that it is poor practice to tighten Gr.8 and stronger fasteners dry and confirmed the corrosion potential in threaded fasteners. It is a big issue in the oil and nuclear industries.

Tonight I welded a 1/2" Gr.8 bolt to a piece of 4130 the same thickness as the engine mount. After tightening it once to allow the threads to make friends, I repeatedly torqued it to 58 lbs and measured both bolt stretch and angular rotation. I then applied low strength Locktite to the threads only and torqued to the same bolt stretch and angle. Voila, 51 pounds.

Great forum, (I found it restoring my SB lathe and Mill) and thanks for the great replies. Hope you find this interesting and/or usefull.

Hope this helps.

 

[WHY]

Hi Jeff

Well, sounds about like what I am reading in the specs for "lubed" torque. So I am going with the "lubed" specs, some of this will be steel to steel and some of it steel to aluminum.

When I use loctite, I usually put some on the bolt threads and then use a piece of tie-wrap cut-off to spread some down into the hole or into the nut, so it is not just at the top of the threads.

Tony

PS some of the charts state that "lubed" is the equivalent of a 10-w oil

 

[WHY]

Just a little side note on the torque wrenches, got one from Harbor freight, looks OK but shortly after getting it I saw this wrench on the NORTHER TOOL & EQUIPMENT site, and really liked it, it has scales in both lbs and nm which I really like, $59.99. Ordered one, it is a "Titan" 1/2 inch drive, model 909147 Really like it !!!!!

Tony