Tightening Nuts To Torque

[FarmerPug]

Thanks for your advice
When i had the drivers side spring done by the mechanic, he used the impact wrench to do all the bolts.
I tried to use the torque wrench to follow the haynes manual when i did the passenger side but my wrench is a 40-210NM wrench so it couldnt reach the 250NM for the lower balljoint. Everything else it torqued right. At times i would check the wheels are on at 90NM but to use a torque wrench every time i do the wheel bolts on a car would be a faff.

The wrench i have is a Teng tools one i bought it last year, it has a dial to measure degrees i assume for head bolts, wold it need to be calibrated yet, there was a calibration certificate inside the box?

[Bailes1992]

I do mine every 12 months or if I haven't used it for a long while.

My little Laser unit I have hasn't been used since I changed the plugs in the Focus back December Dec 2010. Therefore I decided before I do the plugs on the V6 I ought to get it calibrated.
I have a Laser 1/2" that goes up to 200nm but I got it wet working on the 406 beginning of the year and it must have seized up My own fault really!

[FarmerPug]

Theres a few places on the internet do you have it calibrated anywhere in particular.

This teng one was £50, but if it costs that much to get it calibrated its quite expensive, ill need to check its instructions on how often they recommend its calibrated,
how out of tune so to speak can one become, are we talking 1-2NM or a lot more?

[boombang]

Not exactly hard to check the calibration of a torque wrench though - just need a weight, a vice bolted to a workbench, some string and a calculator.

A cheap wrench is very unlikely to be able to be calibrated, instead you'll have to apply a correction factor. Even high end torque wrenches will be out if used for an inappropriate tightening - i.e. a 1/2" drive 4 foot wrench designed for hub nuts will likely be out if you try to do a spark plug to 25lb/ft.