Norbar gearboxes are built to an extremely high standard of precision. All gears rotate on needle roller bearings about hardened and ground journal pins. As a result, Norbar Handtorques can be relied upon to have a torque multiplication accuracy of +4%, throughout the operating range, taking the uncertainty out of high torque tightening.

No gearbox is 100% efficient and so the velocity ratio (the number of turns that the input has to make to achieve one revolution of the output) is not the same as the torque multiplication ratio. Norbar multipliers are engineered such that each gear stage has a velocity ratio of typically 5.45:1 which results in a true torque multiplication factor of 5:1.

Torque output calculations are therefore a matter of simple arithmetic with little risk of incorrect bolt loading due to conversion errors. Other manufacturer's multipliers often require graphs or formulae to calculate the input torque to achieve a particular output.

The Norbar Handtorque is the most comprehensive multiplier range available. Standard products are available up to 47,500 N·m (35,000 lbf·ft) and 'specials' to 100,000 N·m (73,000 lbf·ft). A range of 'nose extensions' for reaching difficult to access bolts and full range of torque transducers for highly accurate torque monitoring are available. 

• 5:1 Torque multiplication, accuracy guaranteed better than +/-4%.
• Supplied with two reaction bar styles for maximum versatility.
• Robust construction means minimal maintenance and long life.
• Supplied in a carrying case, the Highwayman is ideal for inclusion in the heavy vehicle tool kit.
• 1300 N·m version has a spare 3/4" output square included in the kit.
• Multiplier head only (no reaction bars or plastic box) also available.
• Product Video

• True 15.5:1 or 26:1 torque multiplication, accuracy guaranteed better than +/-4%.
• High ratios allow use of a small torque wrench.
• Robust construction means minimal maintenance and long life.
• Supplied in a carry case with replacement square drive.
• Anti Wind-Up Ratchet (Anti Backlash) fitted to allow safer and more practical operation.
• Angle protractor for easy torque and angle tightening.

• 52mm diameter allows excellent access.
• 22:1 and 4.5:1 Torque multiplication ratio.
• Guaranteed accuracy of better than +/-4%.

• 72mm diameter allows excellent access.
• Guaranteed accuracy of better than +/-4%.
• Anti Wind-Up Ratchet available on 25:1 models for easier and safer operation.
• A variety of reaction styles are available for maximum versatility.
• Electronic Torque Transducers can be fitted for precise torque monitoring.
• Available in a variety of ratios and output square drive sizes.
• Product video. 

Handtorque models HT30, 45 and 60 have all the features of the Standard Series, but have a higher torque output for a given gearbox diameter.

• Reduced diameter allows better access, particularly on pipe flanges.
• Reaction taken from high strength spline.
• Reaction foot can slide on the spline to allow for sockets of various lengths (except HT45).
• Anti-Wind-Up Ratchet available on all models (except 5:1 ratios), allowing safer and more practical operation.
• HT45 has integral angle protractor for easy torque and angle tightening.

• True torque multiplication guaranteed better than +/-4%.
• High ratios allow the use of a small torque wrench, multipliers can be used where access is limited.
• Anti Wind-Up Ratchet available on models of 25:1 ratio and above.
• A variety of reaction styles are available for maximum versatility.
• Electronic torque transducers can be fitted for precise torque monitoring.