When you use a Wobble extension or a U-joint extension with a torque wrench do you still get a true reading?
Question about torque wrench use.
- Thread starter Who
- Start date
ANY extension, even a solid one, will alter the actual amount of torque applied. Even more so with a u-joint or wobble.
+1
Any extension you use absorbs energy as it is stressed.
Sometimes it is good to imagine how things work by looking at a far end of the spectrum. Imagine having a 10-foot extension on a 3/8" drive. Put 100lbs of torque at the wrench and see how much of that is absorbed in torsional bending.
The reality of it - if your extension is fairly small and impact-grade, your torque will be quite close. Would I go as far as using an extension to torque something like a head? Probably not.
Any extension you use absorbs energy as it is stressed.
Sometimes it is good to imagine how things work by looking at a far end of the spectrum. Imagine having a 10-foot extension on a 3/8" drive. Put 100lbs of torque at the wrench and see how much of that is absorbed in torsional bending.
The reality of it - if your extension is fairly small and impact-grade, your torque will be quite close. Would I go as far as using an extension to torque something like a head? Probably not.
I use a 6" extension all the time on my engines........
You might be able to measure a small difference in the torque reading but as long as it's a good quality one there shouldn't be any change in consistancy across all 14 studs and this is much more important.
I would imagine not too many people here have their wrench calibrated after purchase so it could easily be out more than this.
You might be able to measure a small difference in the torque reading but as long as it's a good quality one there shouldn't be any change in consistancy across all 14 studs and this is much more important.
I would imagine not too many people here have their wrench calibrated after purchase so it could easily be out more than this.
Ok so in summary.....
High grade straight extensions with no flex joints result in very little error. More importantly if using the extension on a part with several bolts use the same extension for example a Head.
Using a u-joint or a wobble can result in large errors due to the angle of force and probably a slew of other geometric angular blah blah blah calculations.
Thanks guys / gals
High grade straight extensions with no flex joints result in very little error. More importantly if using the extension on a part with several bolts use the same extension for example a Head.
Using a u-joint or a wobble can result in large errors due to the angle of force and probably a slew of other geometric angular blah blah blah calculations.
Thanks guys / gals
not sure about a universal but a extension wont effect torque if you let it click and wait a second-impact very different !!! and if your using a wrench with one of those needles toss it in the garbage if its worth torqueing SNAP-ON MAC
I have a 1/2 inch beam (needle) torque wrench that I use for lugnuts and non critical parts. Every time I use it I wonder how accurate I really am. In my hands there seems to a lot of room for error.
dumbo;1100369 said:
LOLZ. The clicker type is the least accurate. The dial is more accurate, and on top of that, the beam type.
Snap-On is overpriced junk IMO. I've never seen more tools break than with Snap-On. Matco is much more affordable, higher quality, and better service from what I've experienced. Mac is an excellent alternative.
87witmoreboost;1099829 said:
Sometimes it's necessary to use an extension to torque a head, depending on the vehicle/motor...
IJ.;1099832 said:
It just so happens that I checked the Torque specs on both of my new wrenches when I bought them a few months ago -- Craftsman Digi-Torque and a cheapie li'l Harbor Freight one....both were within a lb. of indicated setting on our torque standard....I was esp. surprised that the Harbor Freight one was accurate...LOL!
Orion ZyGarian;1100571 said:
Info from Wiki on torque wrenches types. I always thought the needle beam types were the least accurate. Guess I was wrong.
Beam needle types seem to be very accurate and durable but are subject to greater user error when reading the needle especially at the funky angles for viewing in automobile applications. Click type are precise when properly calibrated but can easily loose their calibration. Read the last paragraph in the Wiki link. Some good info on storing click type wrenches after use.
Attachments
Last edited:
http://www.armstrongtools.com/catalog/products.jsp?groupID=917
This is the one that I use. Very consistant. Also has a buzzer and light when specified torque is met. Actually my work owns it but I use it all the time. Nice becuase they got a set of different drives. Kinda bulky though.
This is the one that I use. Very consistant. Also has a buzzer and light when specified torque is met. Actually my work owns it but I use it all the time. Nice becuase they got a set of different drives. Kinda bulky though.
Many engine builders use the needle type as it is the most accurate and best for torque to yield type bolts.
Needle type also change in different temps... But they are the best, if you have them at the same temp that you calibrated it at.
I find them open to user error.
If you don't look at the scale at exactly 90 degree's each time it will be inconsistant. (same with any anologue gauge)
Ease of use a click type wins hands down.
If you don't look at the scale at exactly 90 degree's each time it will be inconsistant. (same with any anologue gauge)
Ease of use a click type wins hands down.
The click type is nice for ease of use but when ever we get our click types calibrated they always seem to be off a little bit. brand new or in our shop for years. Mainly the cheaper craftsman ones are off the most. In fact our most recent calibration two click type craftman failed miserably was could not be fixed and certified. Then again we use each one multiple times a day everyday so they get used and abused.
But the dial one I mentioned earlier is always perfect and never has to be adjusted by them. And it is almost as easy to set as it is with the click type.
In any case, if your using them to be precise send them out to get checked and NIST certified.
But the dial one I mentioned earlier is always perfect and never has to be adjusted by them. And it is almost as easy to set as it is with the click type.
In any case, if your using them to be precise send them out to get checked and NIST certified.
IMO click is the best for anything on the car for whatever reason pretty much, but anything on the engine itself (valve covers, and definitely head bolts)...well I'm going to buy a beam type just for that reason.
Many fastener applications require torque and hold. Crush washers come to mind. Beams are used in such applications because a clicker releases torque when it reaches it's setting. A good mechanic will own both.