Possible causes of crack occurrence include excessive fastener torque moment, fretting between fastener and hole combined with poor machining that left marks that serve as potential crack initiation points.
Task parameters, including fastener target torque and joint properties (soft, medium or hard), were ascertained from the vehicle design specifications.
Tighten fasteners to ensure proper torque.
These manuals are written for professional mechanics, assume some degree of mechanical expertise, are very detailed in that they state belt tensioner values, bolt torques, fastener locations, etc.
Moreover, during the data acquisition campaign, the tightening torque of the fastener screws was revised, obtaining an average value of 220 Nm.
Herein, the effect of the high temperature cycle occurring during atmospheric re-entry on the reduction of the tightening torque of the CMC fasteners is investigated.
Another finding derived from experiments is that, the joints with fasteners preloaded under 6 Nm tightening torque offer noticeable advantage in terms of stiffness and strength compared with the finger-tightened ones, just as experienced in unaged specimens.
Never use a torque wrench to break loose fasteners.
On the 1.6-Liter engine (the one depicted in the photographs), the fasteners need only 17 to 34 in-lbs of torque.
Composite plates were joined by six fasteners of three different types: composite, titanium Torque-set, and titanium Huck-comp.
