XPC FASTENER
THE STEALTH FIXING FOR TUBULAR STRUCTURES
JUST PUT IT IN AND TIGHTEN IT UP
XPC USES PURE FRICTION TO CREATE A ROBUST, LOAD BEARING END-JOINT IN METAL TUBE


EXPANDING COLLAR FASTENER (XPC) PATENT FILING APPLICATION NO. PCT/GB2005/002788 www.xpcfastener.com


email xpcfastener@aol.com


STEP 1

Pictures show an M16 XPC Fastener and XPC ‘Failsafe’ thrust nutready to be fitted to the alloy tube.

XPC is inserted thru the thrust nut and tightened fractionally by hand to bring the face of the collar into contact with the thrust nut, it will NOT spin in the tube during tightening.

XPC ‘Failsafe’ Thrust Nut is a slip-fit on the tube outer diameter


XPC FASTENER
‘FAILSAFE’ THRUST NUT TM
WON’T LET GO
EVEN WHEN YOU TAKE THE NUT OFF..........!!!


XPC ‘Failsafe’ Thrust nut is designed to offer exceptionally high tensile strength

Here is a demonstration of how XPC can offer high holding strength in this configuration - even with the nut removed.


PICTURES SHOW ONLY XPC SAMPLES MADE FROM CAPSCREWS


STEP 2
The thrust nut is gripped in the vice 100lbf ft preload applied to the fastener.

In the initial tightening phase the tube needs light restraint by hand - just until the outer diameter of the collar grips the tube bore.

Once the preload is set the nut can be removed. The interlocking tapers of the XPC stud and collar will not release on their own. The tube is compressed between the XPC collar and the bore of the thrust nut.


STEP 3

A clevis is fitted at one end, at the other end XPC is used to provide and exposed thread to which a chain is attached.


With nothing more than friction holding it up, the engine is hoisted off the ground with ease - and it weighs 100kg


After the test, the assembly is easily dismantled.

With the clevis removedthe XPC is given a light tap with a hammer to free the tapers, and the thrust nut can be slid off the tube.
Fracture of XPC mild steel collars during dismantling - along the notch line - is quite normal and has no bearing at all on the holding strength of XPC.
The photo of the tube bore (right) shows the linear distribution of compressive stress applied by the smooth XPC collar inside the tube bore. XPC generates intimate frictional force with the tube bore and holds without generating any stress raisers This is what makes it so strong. It had been considered for a long time that holding strength could only be created by means of ribs and teeth on the outer surface of insert fasteners, but experiments at XPC have shown that any kind of disruption to the tube bore weakens the tube very measurably, especially in bending.

XPC SHAFTDRIVE
XPC Fastener with XPC Thrust Nut attached allows a thread to be fixed in tube with a very high degree of concentricity.

The shaft at right is fitted with a plastic XPC collar and is only ‘spanner tight’. The shaft is spinning in perfect safety at 550 rpm.

Shaft runout as shown is only 0.17mm, even with the thread fixed direct in the chuck. There has been no special preparation of the tube bore or outer diameter or XPC itself for this test.