Using a torque wrench?

[ILLaViTaR]

I was just wondering how I'd use a torque wrench.

What I have been doing is turning it normally until it clicks, and after that I tighten further extremely slowly (so there's less torque from me) until it clicks again.

Is this the correct way to use it?

[frd_crzer]

well then u have the torwue setting you want you use it like a normal ratchet but once you hear it click then the bolt has been torqued up

[ratter]

Depends on what type of torque wrench, but the main thing is not to try to undo bolts with it

[ILLaViTaR]

why can't you undo bolts with it?

It was a wrench from autobarn, unsure of brand.

I'll just use it like a ratchet then

[LiL_Macka]

Try not to undo stuff with tension wrenchies, you can send it out of calibration, when you use a tension wrench, the first thing you do is set up what tension you want it to click at, say 50nm, you set it and you tighten the bolt accordingly, try to keep it a smooth movement, no big spikes as that can cause a misreading, you can go either fast or slow, preferably medium speed, if you were doing up something like head bolts you can warp the head if you tension to quickly.

There are other ways to tension, some head bolts say, 210FTLB (Example) and then 90 degrees, that means you tension the bolt to 210 FTLB then you go mark the bolt and then you rotate the bolt 90 degree's. I don't exaclty no why idiot companies like Izuzu do this, i work on trucks for a living, maybe gives them a more accurate torque, there are other wrenches to, like angular wrenches that make doing the degree's tensioning really easy

Regards Macka!

[aussiblue]

There are other ways to tension, some head bolts say, 210FTLB (Example) and then 90 degrees, that means you tension the bolt to 210 FTLB then you go mark the bolt and then you rotate the bolt 90 degree's. I don't exaclty no why idiot companies like Izuzu do this, i work on trucks for a living, maybe gives them a more accurate torque, there are other wrenches to, like angular wrenches that make doing the degree's tensioning really easy

Because like the ones Ford use on their cylinder heads that require they same procedure they are torque to yield bolts. Torque to yield is the method of tightening a fastener so that a high preload is achieved by tightening up the yield point of the fastener material.

see http://www.canadiandriver.com/articles/jk/040303.htm

Tightening torque-to-yield bolts is done in several stages using a combination of torque and turning angle. First, the bolts are tightened to a low torque specification so that even clamping load is placed on the parts being assembled. Often, the bolts are tightened again to a slightly higher torque as a second stage. This is still a low enough torque that friction and stiction on the bolt threads affect tightening torque very little. Then each bolt is turned a specified number of degrees usually in two or three steps. For example, each bolt might be turned 90 degrees, then another 90 degrees and the tightening completed by turning a final 70 degrees. The clamping force exerted by the bolts is accurate and even.
---snip----
Why do we need these torque-to-yield bolts now? We didn't need them in the 1960's or 70's! The simple answer is engine materials are different. Aluminum cylinder heads expand at a different rate than cast iron blocks. As an engine warms up, bolted together parts have to move against each other or slide on their gaskets. The elastic properties of the torque to yield bolts allow movement between parts yet maintain even clamping loads and sealing.

[LiL_Macka]

Well said, i'm only a first year apprentice dont know that much as of yet :P

[LiL_Macka]

Even better again

[aussiblue]

I'm in my mid 50's and still learning and all I know for certain is nobody knows it all. And the beauty of this forum we all share what we know and all contributions are appreciated.

As for using a torque wrench see http://www.virginiawind.com/tips/torque_wrench.asp

[LiL_Macka]

I use them everyday lol, best tool ever, i just didn't understand why they dont just make a set tension instead of saying "lets add another 180 degrees onto that" lol :P