The next step beyond WRIGHT DRIVE®
The Wright Spline is the highest
strength wrench for high strength fasteners and is good for ordinary hex
and 12 pt. fasteners too.
WHAT IS WRIGHT SPLINE? Wright Spline
is unconventional because it takes advantage of two things that have not
previously been considered in wrench design. First, most wrenching problems
occur in removing fasteners because the removal torque is frequently twice
or more the installation torque. The second point is that most fastener
heads are made on the small side resulting in substantial play between
wrench and fastener. Wright Spline is better designed to deal with
WHY IS WRIGHT SPLINE PREFERRED? A
hex fastener produces large, non-productive radial forces, which tend
to split the wrench or damage the wrenching surfaces of the fastener or
wrench. The spline does not have these forces and, therefore, a spline
wrench on a spline fastener will be much stronger than a hex wrench of
the same diameter on a hex fastener. Wright Spline is an advanced
HOW DOES WRIGHT SPLINE WORK? Fasteners
have gone from 60,000 psi tensile strength to over 180,000 psi, a 3:1
range. In addition, the use of the small 12-pt. fastener heads requires
smaller wrenches to have twice their customary strength required to turn
6-pt. fasteners. Highest strength wrench for high strength spline fasteners
and for ordinary hex and 12-pt. too! This results in a six-fold increase
in required strength. Traditional 12-point wrenches were designed for
single hex fasteners long before 12-point fasteners were in use. Although
quality wrenches have been much improved in design and manufacture, they
cannot cope with a six-fold increase. It is necessary to go to a new and
unconventional profile-Wright Spline.
WHY USE A WRIGHT SPLINE ON A HEX NUT?
The Wright Spline was created to have the same diameter as standard
wrenches. It transmits about the same amount of torque to hex and double
hex fasteners as traditional wrenches. But, it has the advantage that
contact is made far away from the corner; therefore, it does not depend
on the existence of the corners and does not damage the corners further.
It is for this reason that this wrench not only can turn all four styles
of fastener heads, but also is the better design because it can turn the
undersized and damaged fasteners better.
WHY USE A WRIGHT SPLINE ON TITANIUM AND OTHER
LIGHT WEIGHT MATERIALS? These fasteners require less torque because
they have less strength but they will still benefit from a high-strength
spline wrench. The greater efficiency of the Wright Spline produces
relatively lower forces, and the larger bearing area results in lower
relative contact pressures.
WHY SPLINE WRENCHES AND FASTENERS? The combination
of spline wrenches and spline fasteners can deliver twice the torque of
12-pt. wrenches on double hex fasteners and still more torque than hex
wrenches on hex fasteners. This is done without any increase in the outside
diameter of the wrench. This allows the use of higher strength bolts and,
it allows these fasteners to be tightened to higher loads. Even more important,
it allows these fasteners to be removed with less difficulty. Like many
new ideas, they are being used first in aerospace, where weight and time
savings justify their premium cost. Wright Tool has an improved design
for fasteners which will lower the manufacturing costs and make splines
more widely used. Also, splines are a good replacement for hollow head
cap screws because they can work in the same space, and the new design
is easier to clean than the hole of a socket head cap screw.
If a mechanic has a set of spline wrenches, he will find that they will
turn single and double hex 12-point fasteners with corners that are too
badly damaged to be turned with other wrenches. Also, they are superior
for double hex fasteners. Some mechanics find that it pays to replace
double hex headed fasteners with spline fasteners to make them easier
to remove in the future.
Both diagrams below are for the same torque. But, the total force on
the spline is only 40% of the total force on the hex tooth. The length
of the red arrow represents the total amount and direction of force between
wrench and fastener. With typical clearances, the fit is better and the
contact area is 44% more.
Double Hex Wrench and 12-Pt. Fastener
Wright Spline Wrench and Fastener