[R-390] Torque and Clamps

[Charles P. Steinmetz]

Glenn wrote:

>There are some torque screwdrivers on ebay, made in China, that look 
>fine for $25.
>Also note the interface of my Utica TS 30 to the Xccellite #6 Fluted 
>Bristol wrench VIA the Xcellite 99PA adapter. This may work with the 
>offshore version as well.

Unfortunately, the eBay unit appears to use bits with round shanks 
and flanges, similar to (but almost certainly incompatible with) the 
Xcelite 99 design -- not 1/4" hex bits.  But at the price, it might 
well be worth buying one to play with.

Here is another possibility, one that I use:

http://www.all-spec.com/products/0490-22.html

It's the Milwaukee 0490-22 cordless screwdriver with an electronic 
torque stop variable from 3.5 to 30 in-lb in both directions.  I have 
three, and mine are extremely repeatable (though not calibrated -- 
the scale runs from 1 to 21 plus lock).  I see the price has risen 
sharply since I bought mine, but they are widely distributed and I 
think you can still find them for less if you look.  I've been using 
"flate rate screwdrivers" for years, and these are by far the best 
I've ever used.  It's not surprising that this model has been in 
production for more than 5 years (in a world where 2 years is almost 
unheard of for products like this).  And, unlike my mechanical 
torque-limiting screwdrivers, I use them almost every day for every 
conceivable kind of project.

IMO, the optimum torque for 390/390A clamps is 4 to 4.5 in-lb.

Best regards,

Charles