Please go to this link to find the latest version

Installation & Removal

Installation Instruction for Superbolt Tensioners


Please follow the instructions below for the correct installation and removal of Superbolt tensioners.


This instruction excludes piston end, crosshead, mill motor & bearing lock nuts.


Exclusion of liability: The Nord-Lock Group excludes all liability based on unsuitable product selection for specific applications, improper use as well as all types of damages resulting from disregarding our instructions and directives. Changes due to technical progress are reserved to the Nord-Lock Group.



Superbolt Product: Confirm jackbolts are lubricated with correct Superbolt lubricant (JL-G, JL-M or JL-AS). New product is lubricated at the factory. Make sure the jackbolt tips are even (or recessed) with the bottom of the nut body.

Torque Wrenches: Based on your target torque (which is provided with your order) select the appropriate hand tools.

Sockets: High hex stresses require the use of quality six-point impact sockets. Have several spares handy for each job and replace them at the first sign of wear. Special Superbolt sockets may be required when using a 3/4” impact or torque wrench and jackbolt spacing is close.

Target Torque Data: Determine the target jackbolt torque supplied with your order.

Note: The jackbolt torque stamped on the tensioner is a standard value for that part and may not be correct for your application. If you are unsure, contact Superbolt.



Air Impacts: If using air impacts, select a tool with an output of about 100% - 120% of the target torque. See “Air Impact Tool Selection”.

Lubricants: Jackbolts are pre-lubricated from the factory with the correct Superbolt lubricant. For the main stud, any standard anti-seize lubricant can be used.

Note: For reuse, the jackbolts should be removed, cleaned and re-lubricated with the correct Superbolt lubricant.

Washers: Apply the correct Superbolt lubricant to the washer face.

For flanges: To speed up installation, use two workers at 180º apart, following OEM pattern for tightening.



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.

Note: Product with 4 or 6 jackbolts – use a star pattern for all steps.


Caution: Jackbolts must be unloaded gradually. If some jackbolts are fully unloaded prematurely, the remaining jackbolts will carry the entire load and may be hard to turn. With extreme abuse, a jackbolt tip can deform, making removal difficult.

Service Under 250ºF

Preparation: Spray jackbolts with penetrating oil or hydraulic oil prior to start (especially if product is in a corrosive environment).

Note: Prior to reuse, remove, clean and relubricate the jackbolts with the correct Superbolt lubricant. The washer may also be reused. Small depressions on the washer are normal.

Step 1: Loosen each jackbolt 1/8 turn following a circular pattern around the tensioner (1 round only). As you move around and get back to the first jackbolt, it will be tight again. Do this for all studs on the joint prior to the next step.

Step 2: Repeat a 2nd round as above for all studs, now loosening each jackbolt 1/4 turn in a circular pattern.

Step 3: Continue loosening 1/4 turn for 3rd and successive rounds until all jackbolts are loose, then remove the tensioner.

Note: Usually after the 3rd or 4th round, an air impact can be used to completely extract the jackbolts, one by one. For long bolts or tie rods, additional rounds may be required before removing the jackbolts with an impact tool.

Service Over 250ºF

Note: Above 250ºF, the petroleum base of the lubricant burns off. Oil per “Step 1” below to reduce the removal torque.

Note: Heating rods can be used to reduce the removal torque required.

Step 1: As the equipment is cooling down (around 300ºF), apply penetrating oil to the jackbolts and washer and let sit for several hours. Thoroughly “wet-down” all components and re-apply during equipment cool-down period. If the tensioner is inverted, squirt oil in the gap between the nut body and the washer. Synthetic oil can be used for oiling above 300ºF.

Step 2: Wait for tensioners to cool below 200ºF. Using a circular pattern, "crack” each jackbolt only enough to ensure movement. Do not turn beyond the break-loose point. Do this for all studs.

Step 3: Now begin with “Step 1” of the procedure for service under 250ºF.

Helpful Tips

Air Impact Tool Selection (90 psi air pressure) 

Note: The jackbolt torque actually achieved by an air impact wrench is usually only 30 - 50% of its rated output. For minimum hand work, use an air impact with an output of 110% - 120% target torque. For maximum power, use the largest air line fitting.

Up to 70 ft-lbs: For 15 - 35 ft-lbs use a right angle ratchet or light duty 3/8” impact. For 35 - 70 ft-lbs use a heavy duty 3/8” impact.
70 - 100 ft-lbs: Use a light duty 1/2” impact at a reduced pressure or setting. (Be careful not to overtighten! Calibrate the impact before starting.)
100 - 170 ft-lbs: For 100 - 130 ft-lbs use a light duty 1/2” impact. For 130 - 170 ft-lbs use a heavy duty 1/2” impact.
170 - 200 ft-lbs: Use a light duty 3/4” impact on low setting. Some heavy duty 1/2” impacts will also reach this range.
Over 200 ft-lbs: For 200 - 300 ft-lbs, use a light- to medium- duty 3/4” impact. Over 300 ft-lbs, use a heavy duty 3/4” impact.

Calibrating an air impact wrench: Tighten one jackbolt to the desired torque with your torque wrench. Then, apply the air impact tool and increase the pressure until the jackbolt starts turning again.

Prior to Tightening

1) Check threads of main stud: If possible, verify that the tensioners spin on prior to the installation date. If a tensioner is tight or will not thread on, try using a lapping compound on the main thread and work the tensioner in a back-and-forth motion, making small advances when the thread loosens up. If necessary, chase the studs with a die.

2) Use of spacers: Tensioners should be positioned at the ends of the studs to minimize exposed threads and facilitate easy access to the jackbolts. A spacer (or stacked washers) can be used beneath the special hardened washer to accomplish this. A spacer will also “step over” a damaged area on a stud where years of bolting have deformed the first few threads.

3) Back the tensioner off before tightening to provide 1/16” to 1/8” gap: The additional jackbolt extension provides easy access for oiling the jackbolt tips prior to removal. This is especially beneficial for oiling when the tensioners are inverted. Note: There may be insufficient jackbolt stroke to allow this step when tensioning exceptionally long bolts or tie rods, or when closing a gap between flanges.

4) For spinning the tensioner on and off the stud: Two deep well sockets inserted over two jackbolt hexes at 180º apart can serve as “handles” for spinning the tensioners on and off the studs.

For Removal

1) 1/4 turn or less!: Removing the jackbolts more than a 1/4 turn will increase the removal torque of the remaining jackbolts and you may get stuck. If this happens, you will have to retighten and start again.

2) Stuck jackbolt removal: If a jackbolt will not turn, remove, re-lube, and retighten a neighboring jackbolt at 110% of the recommended target torque and then try to turn the stuck jackbolt.

For stubborn removal, please contact us for alternate procedure.