SPRING 2011

THE DISTRIBUTOR’S LINK 71
HOW TORQUE VALUES VARY continued from page 10
A rough surface will inhibit the required amount of work
to be applied to turning the wrench while a lubricant will
not provide any resistance at all. This can help larger
fasteners to become tighter than without a lubricant, but
will destroy smaller fasteners.
This is of extreme importance when assembling a
multiple bolted joint: all the fasteners must be of the
same surface finish condition. A non-plated fastener will
take much more torque to tighten than a plain zinc coated
fastener. The connection will be compromised if the
same torque is used for all fasteners in the connection.
An average man can pull about 100 pounds without
bracing himself. If he had a one foot lever, the output
would be 100 lb-ft of torque. If using an 18” lever, the
output would be 150 lb-ft. Using the torque values on the
next page, you can see where 100 lb-ft of torque may
tighten a 1/2”-13 dry Grade 8 fastener but also be close
to a 5/8”-11 lubricated Grade 8 fastener. Or, 150 lb-ft
with the extended lever wrench is way too much for the
1/2"-13 dry and lubricated Grade 8 fastener and will be
too much for the 5/8”-11 Grade 8, but is close to the
lubricated 5/8”-18 Grade 8 fastener.
As one can imagine, it becomes physically impossible
to properly tighten even a 1/2" diameter Grade 8
fastener, and higher strength fasteners, by hand without
using an efficient lubricant.
Ever wonder about your tire’s lug nuts?
Suggested Torque Values for Inch Fasteners..
.*All values in pound-feet.
All lubricated values are calculated using metallic anti-seize compounds on
zinc plated bolts.