Correct Fillister head engine case screws are manufactured to original specifications by LF Harris in the UK. The 34-piece set is suitable for the chaincase, gearbox, and timing covers on 1954-1962 Triumph Pre-Unit twin cylinder models.
The set includes:
- (1) 3″ UH
- (5) 2-1/2″ UH
- (3) 1-9/16″ UH long thread
- (3) 1-9/16″ UH short thread
- (1) 1-1/2″ UH
- (21) 15/16″ UH screws,
all threaded in 1/4-20 TPI British Standard Whitworth (BSW). These Fillister head screws feature a 3/8″ diameter head with a slightly domed top for correct fitment into the cutaways on the engine covers. Finished in zinc plating for corrosion resistance and a crisp appearance.
The case cover screws feature a Pozidriv recess on the heads for excellent cover retention and an oil-tight seal. When used with the correct screwdriver, these screws can be tightened to an increased torque value without annoying “cam-out”, or slippage occurring within the drive recess on the screw head.
It is advisable to clean the threads in the crankcase and gearbox with a tap to allow for best thread retention and an oil-tight seal between the covers and the crankcase. Thread locking compound is not recommended for use on cover screws.
LF Harris motorcycle spares are produced to the highest quality standards possible utilizing original Triumph tooling, dies, factory blueprints & materials combined with modern manufacturing equipment, tolerances & techniques.
