I
recently bought a unusual NOS metric torque wrench from someone on eBay.
It is made by a company whose trade mark on the tool is the letters "VLC" and
was sold to VW dealerships through the Zelenda Metric Tool company, a long time and still
current provider of specialized tools to VW dealerships and mechanics. It can be
seen being used by VW technician/mechanics in the Split-Bus Factory Bentley Manual,
generally on parts and fasteners that seem to require presice, but very small amounts of
torque. You can see a photo of this wrench in the "Steering Gear" section
(V-9) on page 9. There it is shown being used to properly adjust the steering taper
roller bearing
with a torque value of only 2 to 3 cmkg. It can also be seen in the Transmission
section (H-7) on page 4a, bottom photo being used to check for proper torque on the pinion
assembly. The shaft for sockets on this torque wrench is 1/2 inch and it reads in
torque values from 0 to 35 cmkg (not mkg). Can any of you machinists or engineer
types out there point me to a conversion chart that converts "cmkg" to "ft.
lbs" and visa versa?
It's obvious that this "cmkg" scale is used for smaller or lower levels of
torque than the ft. lbs. scale we are more used to.
Let's say that you didn't want to over torque some fastener on your Bus that VW has placed
a small or low torque value on. For example, I seem to recall that VW calls for a
torque value of 5 or 6 ft. lbs. for the six "cap nuts" that hold your oil
strainer plate to the bottom of your engine. If you wanted to use this torque wrench
to get it just right and not risk stripping out those small, fine threaded studs, what
value in the "cmkg" scale would equal 5 to 6 ft. lbs.? There's got to be a
conversion chart in print somewhere, or perhaps on the internet somewhere. I just
haven't stumbled upon it yet, so can anyone help or point me to it. I'm obviously
interested in putting this wrench to good use around my garage pretty soon.
Thanks for any assistance you can provide!
Bill Bowman - NEATO |
Ah
Yes, Sir William,
I would love to use my expertise to help you.
You are right is stating that the cmkg scale is for light torque values. Cmkg is
translated as centimeter kilograms, similar to the foot pound or inch pound scale we have
here (I am sure you know this).
Here is the translation:
(1 cmkg) * (1 in/2.54cm)*(2.2 lbs/1 kg)=.866 in-lbs
Therefore, 1 cmkg = .866 in-lbs (units conversion)
If you are given a torque spec in cmkg and want inch pounds, (have Bently book and
Craftman torque wrench), take the torque value in cmkg and multiply it by .866 to get the
proper inch pound value.
If you are cool and have the NOS Kraut wrench, but have a Haynes manual which gives values
in inch pounds, take the published inch pound number and divide it by .866 to get
the proper cmkg number.
Oh oh, strainer nuts require a torque of 5-6 ft-lbs (I am going back and re-reading your
email). ok, more translation:
1cmkg=(.866 in lbs)*(1ft/12in)=.072 ft-lb (units conversion)
therefore 1 cmkg= .072 ft-lb.
back to above:
Bently book, Craftsman wrench--cmkg value, foot pound torque wrench: multiply cmkg value
by .072 to get foot pound value.
Kraut wrench, Haynes manual--foot pound value, cmkg torque wrench: divide foot pound by
.072 to get cmkg value(if the wrench can go that high).
therefore: 6 foot pounds = 83.3 cmkg
Hope this helps,
Matt |
