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What is a lock bolt ?. No threads but lock grooves No nut but collar No torque but clamp No friction but direct tension. Form. Pin. Collar. Break Groove. Pull Grooves. Lock Grooves. How Bolts Work. The idea is clamp The method is torque There’s the problem!
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What is a lock bolt ? • No threads but lock grooves • No nut but collar • No torque but clamp • No friction but direct tension
Form Pin Collar Break Groove Pull Grooves Lock Grooves
How Bolts Work The idea is clamp The method is torque There’s the problem! Torque doesn’t determine clamp Distance does The distance the bolt is stretched!
How Bolts Work Torquing s - t - r - e - t - c - h - e - s the bolt The bolt acts like a spring The spring holds clamp in the joint Clamp should exceed service loads of the fastener
How Bolts Work An uphill battle! Threads are inclined planes Wrapped around a cylinder Twisting or ‘torquing’ pushes nut thread ‘up’ bolt thread
Installation Sequence For 1/2" through 1-3/8" diameter lock bolts, the installation tool is powered by hydraulics. Low voltage electricity from the installation tool is used to actuate hydraulic valves for pull (swage) and return (eject) cycles. An installation sequence is shown in Figure 2. Installation tools are shown in Figure 3. Figure 2
1-3/8” LOCK BOLTS & COLLARS COLLAR PINTAIL LOCK BOLT WITH PINTAIL PINTAIL-LESS LOCK BOLT
PINTAIL-LESS TYPE PINTAIL TYPE 1-3/8” INSTALLATION TOOLS
PINTAIL-LESS LOCK BOLT INSTALLATION
TENSION ONLY TENSION + TORQUE BOLT TENSION BOLT ELONGATION TORQUE INDUCED TENSION VERSUS TENSION INDUCED TENSION
BOLT PRELOAD VARIATION BY TYPE AND METHOD TYPEMETHODVARIATION TORQUE IMPACT WRENCH ± 45% TORQUE FEEL ± 35% TORQUE TORQUE WRENCH ± 30% TENSION TURN OF NUT ± 15% TENSION LOAD INDICATING WASHER ± 10% TENSION ELONGATION MEASUREMENT ± 5% TENSION SWAGED LOCK BOLT ± 5%
INSTALLING A FLANGED COLLAR ON A 10° BEVELED SURFACE
LOCK BOLT NO GAP COLLAR STD. BOLT GAP NUT LOCK BOLT & COLLAR STANDARD BOLT & NUT