Operating The Torque Wrench [instructions]

[Stefan Mikes]

The torque wrench allows tightening bolts with a precise value of torque (which is a twisting force). Here's a quick how-to:

The tool parts explained: A - Extender release button; B - The rotation direction switch (now in the position to tighten bolts in clockwise direction); C - The shaft; D - The torque scale; E - The crown with micro-adjustment scale; F - The shaft release ring.

To assemble: Press the release button (A) then push the extender onto the square block in the direction (B).

Select your chosen bit (A) from the box and insert it onto the extender's end. The Pro Bike Tool comes with Hex and Torx bits of different sizes. I chose the H5 bit for the demo.

Currently, the wrench is set to 5 Nm torque value. The crown edge is aligned with the number 5 on the scale and the 0 indicator is aligned with the vertical axis of the scale.

To set the new torque value, pull the release ring down with your thumb and the index finger. While keeping the ring in the bottom position, rotate the shaft with the extender as shown. Each full turn clockwise increases the set torque value by 1 Nm. (Of course rotating the shaft anti-clockwise decreases the set torque value with 1 Nm for each full shaft turn).

The torque value is now set to 15.0 Nm. (It was necessary to make 10 full shaft turns to go from 5 to 15 Nm).

Pre-tighten your bolt delicately with an ordinary Allen key (that saves a lot of turns to be made with the torque wrench otherwise). Insert the bit inside the socket of the bolt head. Grasp the extender with your weaker hand and keep the handle of the torque wrench with your stronger hand. In case of normal bolts (that tighten clockwise), make a half turn (or so) anti-clockwise to gain the rotation angle. The wrench will rattle meaning the extender won't rotate, as an internal clutch is working.

Now pull the handle firmly towards you clockwise. No sound but the extender will rotate and the bolt will be tightened.

Repeat the "rattle" and "tighten" movements until you hear a loud CLICK and you feel the wrench "has broken". You have tightened the bolt with the desired torque. Do not try to tighten the bolt more!

Dismantle the torque wrench into its pieces and store in the box.

 

[TS25]

Finally: release the torque wrench ("open" it anti-clockwise) fully.
Never ever store it in a compressed status.

 

[Mike TowpathTraveler]

Outstanding, Stefan Mikes!

 

[smorgasbord]

Couple additions:

• Some torque wrenches don't have a rotation switch - they only work in the tighten mode (clockwise).
• I wouldn't call the ratcheting a "rattle," it's just a normal ratchet, like you'd find on any socket wrench (and even many rear bicycle hubs).
• It's not shown in the diagrams, but the wrench "break" happens at the pivot point, which is just beyond the head. In the first diagram, it's the black dot below the "B" lever.
• Best practice is to glide into the torque setting. Once the bolt has stopped turning it's harder to get an accurate torque since you have to first overcome locked resistance to get it going again. So, don't stop turning when you're close to the desired torque, keep going until the wrench tells you to stop. It's OK to stop when you're not near the final torque.
• If you don't need the extender, don't use it. You want to keep the wrench head perpendicular to what you're tightening and the longer the effective distance the harder it is to keep it perpendicular.
• I've found that for brake calipers, which often have tight clearances with the front fork or rear seat stays (or swing arm on a full-suspension bike), the bit holder can get in the way. I've bought a few long hex bits with a 1/4" socket end built-in:

You can buy them separately or in a kit. Here's a 5mm one on Amazon: https://www.amazon.com/gp/product/B07CT7YMYJ
Bits with the built-in socket are also just easier to pop on and off in my experience.

 

[Deacon Blues]

Yesterday I took the rear cassette off my winter road bike to give it a good cleaning. When I put it back together I noticed it had a torque setting on the outer locking ring of 40 Nm. I took out my trusty Nm bike torque wrench only to find it didn't have a max setting anywhere even close to 40Nm.
My solution was to use my iPhone and ask Siri for a Nm to Foot/pound conversion. Siri connected me to a conversion site, which told me that 40Nm worked out to approximately 29 foot/pounds.
I was then able to use my foot/pounds torque wrench to torque down the outer ring.
The internet is a wonderful thing.

 

[jaizon]

Great job, Stefan. Thanks.

 

[steve mercier]

The torque wrench allows tightening bolts with a precise value of torque (which is a twisting force). Here's a quick how-to:

View attachment 50917
The tool parts explained: A - Extender release button; B - The rotation direction switch (now in the position to tighten bolts in clockwise direction); C - The shaft; D - The torque scale; E - The crown with micro-adjustment scale; F - The shaft release ring.

View attachment 50918
To assemble: Press the release button (A) then push the extender onto the square block in the direction (B).

View attachment 50919
Select your chosen bit (A) from the box and insert it onto the extender's end. The Pro Bike Tool comes with Hex and Torx bits of different sizes. I chose the H5 bit for the demo.

View attachment 50920
Currently, the wrench is set to 5 Nm torque value. The crown edge is aligned with the number 5 on the scale and the 0 indicator is aligned with the vertical axis of the scale.

View attachment 50921
To set the new torque value, pull the release ring down with your thumb and the index finger. While keeping the ring in the bottom position, rotate the shaft with the extender as shown. Each full turn clockwise increases the set torque value by 1 Nm. (Of course rotating the shaft anti-clockwise decreases the set torque value with 1 Nm for each full shaft turn).

View attachment 50922
The torque value is now set to 15.0 Nm. (It was necessary to make 10 full shaft turns to go from 5 to 15 Nm).


View attachment 50923
Pre-tighten your bolt delicately with an ordinary Allen key (that saves a lot of turns to be made with the torque wrench otherwise). Insert the bit inside the socket of the bolt head. Grasp the extender with your weaker hand and keep the handle of the torque wrench with your stronger hand. In case of normal bolts (that tighten clockwise), make a half turn (or so) anti-clockwise to gain the rotation angle. The wrench will rattle meaning the extender won't rotate, as an internal clutch is working.

View attachment 50924
Now pull the handle firmly towards you clockwise. No sound but the extender will rotate and the bolt will be tightened.

Repeat the "rattle" and "tighten" movements until you hear a loud CLICK and you feel the wrench "has broken". You have tightened the bolt with the desired torque. Do not try to tighten the bolt more!

Dismantle the torque wrench into its pieces and store in the box.

GOOD ...now if only you had written ALL the manuals I have ever read, I would have saved enough time to bike across Canada.

 

[Stefan Mikes]

Couple additions:

• Some torque wrenches don't have a rotation switch - they only work in the tighten mode (clockwise).
• I wouldn't call the ratcheting a "rattle," it's just a normal ratchet, like you'd find on any socket wrench (and even many rear bicycle hubs).
• It's not shown in the diagrams, but the wrench "break" happens at the pivot point, which is just beyond the head. In the first diagram, it's the black dot below the "B" lever.
• Best practice is to glide into the torque setting. Once the bolt has stopped turning it's harder to get an accurate torque since you have to first overcome locked resistance to get it going again. So, don't stop turning when you're close to the desired torque, keep going until the wrench tells you to stop. It's OK to stop when you're not near the final torque.
• If you don't need the extender, don't use it. You want to keep the wrench head perpendicular to what you're tightening and the longer the effective distance the harder it is to keep it perpendicular.
• I've found that for brake calipers, which often have tight clearances with the front fork or rear seat stays (or swing arm on a full-suspension bike), the bit holder can get in the way. I've bought a few long hex bits with a 1/4" socket end built-in:

View attachment 50978View attachment 50979

You can buy them separately or in a kit. Here's a 5mm one on Amazon: https://www.amazon.com/gp/product/B07CT7YMYJ
Bits with the built-in socket are also just easier to pop on and off in my experience.

Thank you very much for the useful information @smorgasbord! Just to explain: Not only is English my second language but I'm not a mechanical engineer either You can ask me about "enthalpy" though, haha.

Steve, writing instruction manuals for my discipline (process engineering) belongs to my work. I deal with CHEMCAD process simulation software (of Houston TX).

 

[Bigal1463]

Thanks Stefan Mikes, great report. You’re always offering good advice.

 

[FlatSix911]

The torque wrench allows tightening bolts with a precise value of torque (which is a twisting force). Here's a quick how-to:

View attachment 50917
The tool parts explained: A - Extender release button; B - The rotation direction switch (now in the position to tighten bolts in clockwise direction); C - The shaft; D - The torque scale; E - The crown with micro-adjustment scale; F - The shaft release ring.

View attachment 50918
To assemble: Press the release button (A) then push the extender onto the square block in the direction (B).

View attachment 50919
Select your chosen bit (A) from the box and insert it onto the extender's end. The Pro Bike Tool comes with Hex and Torx bits of different sizes. I chose the H5 bit for the demo.

View attachment 50920
Currently, the wrench is set to 5 Nm torque value. The crown edge is aligned with the number 5 on the scale and the 0 indicator is aligned with the vertical axis of the scale.

View attachment 50921
To set the new torque value, pull the release ring down with your thumb and the index finger. While keeping the ring in the bottom position, rotate the shaft with the extender as shown. Each full turn clockwise increases the set torque value by 1 Nm. (Of course rotating the shaft anti-clockwise decreases the set torque value with 1 Nm for each full shaft turn).

View attachment 50922
The torque value is now set to 15.0 Nm. (It was necessary to make 10 full shaft turns to go from 5 to 15 Nm).


View attachment 50923
Pre-tighten your bolt delicately with an ordinary Allen key (that saves a lot of turns to be made with the torque wrench otherwise). Insert the bit inside the socket of the bolt head. Grasp the extender with your weaker hand and keep the handle of the torque wrench with your stronger hand. In case of normal bolts (that tighten clockwise), make a half turn (or so) anti-clockwise to gain the rotation angle. The wrench will rattle meaning the extender won't rotate, as an internal clutch is working.

View attachment 50924
Now pull the handle firmly towards you clockwise. No sound but the extender will rotate and the bolt will be tightened.

Repeat the "rattle" and "tighten" movements until you hear a loud CLICK and you feel the wrench "has broken". You have tightened the bolt with the desired torque. Do not try to tighten the bolt more!

Dismantle the torque wrench into its pieces and store in the box.

Well done! Maybe we should do a how-to on digital torque wenches?