Multi-Jackbolt Tensioners
Superbolt multi-jackbolt tensioners (MJTs) replace existing hex nuts. Only hand tools are required for installation and removal of any size tensioner. Safe, accurate and economical! We have a wide range of standard series, as well as an unlimited capacity to create special designs to meet your unique needs.
INSTALLATION GUIDE
Step 1
Lubricate the thread of the main stud and slide the hardened washer onto the stud. Spin the tensioner onto the thread until it seats against the washer. Then back the tensioner off to provide a small gap between the nut body and the washer.
Step 2
Tighten (4) jackbolts at 90º apart on all studs with a partial torque of approximately 50% (this serves to seat the flange). If using an air impact, use a reduced setting or lightly pulse the trigger.
Step 3
At 100% target torque, tighten the same (4) jackbolts on all studs.
Step 4
At 100% target torque, tighten all jackbolts in a circular pattern. Do this procedure for all studs (1 round only). See Helpful Tip #6
Step 5
Repeat “Step 4” until all jackbolts are stabilized (less than 20º rotation). This usually requires 2-4 additional passes. If using air tools, switch to a torque wrench when socket rotation is small. Use the torque wrench to stabilize at the target torque.
Step 6
Product with 4 or 6 jackbolts – use a star pattern for all steps.
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