There are electronic  torque wrenches now.

here's just one
http://tinyurl.com/6zv99o6

or search 'electronic torque wrench.'

the craftsman one above ( $ 180 ) sounds pretty fancy.

Scott
turbovans
----- Original Message -----
From: "Gary Bawden" <goldfieldgary@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Tuesday, September 27, 2011 8:51 PM
Subject: Re: Torque Specs - Lug bolts and nuts

> Whatever current Proto torque wrenches claim, I'm not sure. But at the
> time,
> I had access to a torque wrench tester, and had drawn a curve for my
> wrench
> vs. the actual reading. IIRC it was fairly close in the middle of the
> range,
> but quite a bit off (like almost 20%) at the high and low ends. This was a
> clicker-style wrench from the 1970's, 1/2" drive, 250 lb-ft capacity.
>
> The point is, torque wrenches are not laboratory instruments - - you
> should
> expect them to have a tolerance, just as one should expect EVERY measuring
> instrument (even laboratory instruments) to have a tolerance, which is
> another way of saying, they may be off by a certain amount. Just a part of
> basic awareness, one should know what sort of tolerance to expect from
> whatever you are using to measure anything that is measurable. That being
> said, at the time, a beam-type torque wrench was considered to be more
> accurate than a clicker-style torque wrench, but as I mentioned in my
> previous message, just how many people took care to get a proper reading,
> i.e., without a parallax error? I remember that the Snap-On torque
> wrenches,
> the beam type, had optional electrical contacts that would turn on a
> light,
> or sound a beep, at the selected torque value, and if I remember
> correctly,
> Snap-On claimed 5% tolerance for their wrenches. Not everybody could
> afford
> Snap-On, however!
>
> I believe the engineers know this, and set torque values to a number that
> they believe will do the job, without over-stressing the part. And as has
> been pointed out by others, it's the uniformity of torquing fasteners (at
> least on parts having more than one) that is probably more important than
> the actual torque value. So if you are using a reasonably good torque
> wrench, even if it may be off by quite a few percent, it is probably
> repeatable, which is a different thing than being accurate. In other
> words,
> if all five lug nuts, for instance, are torqued to the same value, and are
> in the proper range of torque, that is probably more important than
> whether
> or not they are all torqued to 118 lb-ft, or 133 lb-ft. But as I am not an
> engineer, it is just IMHO!
>
> And just for grins, I think I may still have one of the old Proto
> catalogs,
> so I'll look and refresh my memory of what they claimed for that era.
> Also,
> I should point out that the statement, "the technology in clicker-type
> wrenches hasn't changed", may be true, but the technology MAY have been
> refined. :^)
>
> Gary
>
>
>> At 12:02:24 27 Sep 2011, Mike S <mikes@FLATSURFACE.COM> scribed,
>>
>> I'm not sure Gary's remembering accurately. Current Proto torque
>> wrenches are "Calibrated to +/-3% in clockwise direction and +/-6% in
>> counter clockwise direction," so much better that 20%. The technology
>> in "clicker" type wrenches hasn't changed. If you don't get them
>> calibrated occasionally, or don't reset them to the minimum setting
>> after every use, then the calibration could be off, but probably not by
>> 20%.
>>
>
> At 07:35 PM 9/26/2011, John Rodgers wrote...
>>If Gary Bawden's plus or minus 20% rule applies - the would be low
>>-98.4
>>ft-lbs and high - 147.6 ft-lbs and that figure is a whole bunch!