On Tue, 20 Feb 2018 19:17:21 +0000, alan_m
wrote:

On 20/02/2018 18:57, ultred ragnusen wrote:

I've never calibrated my torque wrenches, where I have a few 1/2-inch drive
ones (beam and click), 3/8-inch drive (click) and 1/4-inch drive (click)
where all the click types are from Harbor Freight, so I'm unsure of
accuracy.

I doubt if the manufactures calibrated them.


A good one comes with a calibration report.

The aim would be to get it
right by manufacture to what ever tolerance level is acceptable and then
perhaps test each one at a single setting (without performing any
adjustments) and perhaps test one in a thousand at different settings to
make sure that the manufacturing process is still correct.

These are "precision instruments" Mabee a Horrible Fright one may
not be calibrated, but a Snap-On or Craftsman or other "brand name" or
"proffessional" one will be.

Proper calibration costs money and unlikely to be performed on anything
other than something used for mass production where expensive
calibration costs are amortised over tens or hundred of thousands of
production items or individual use where safety is paramount.

Something you can buy at the local hardware store for less than £100 or
$100 is unlikely to have been individually calibrated or finely
adjusted. It is more likely to have had a go/no test after production.