In 1942 the "North Bar Tool Company" (as Norbar was then known), became the first company to commercially manufacture a torque wrench. The initial demand was driven by the need for the gasket-less cylinder head of the Rolls Royce Merlin engine to be accurately tightened. Bill Brodey and his partner Ernest Thornitt obtained a license from war-time Government to begin manufacture of torque wrenches and Norbar was born.
Since then, Norbar has continued to invest in the very latest design, manufacturing and quality control technology to achieve the highest level of innovation and precision in the field of torque control equipment.
The company has grown from strength to strength and now has one of the largest and most modern plants in the World devoted exclusively to the design, development and production of torque tightening and measuring equipment.
Norbar is owned solely by the descendants of the founder, Bill Brodey, and they remain every bit as passionate about providing customers with high quality, value for money products and services.
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 Hand torques 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 Hand torque 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.
Hand operated torque multipliers are ideal for low volume or intermittent use or when there is no power source available. However, for production lines or whenever a large number of bolts is involved, a powered multiplier will save a considerable amount of time.
Pneutorque operation is quiet - less than 85dB(A) with absolutely no impacting. These two factors make Pneutorques comfortable for the operator to use, reducing fatigue and consequently increasing safety.
Pneutorques provide accurate torque control - on a given joint they will stall repeatably to within +5%. Using electronic shut off, this repeatability can be improved to +1%.
The Pneutorque consists of a robust air motor driving a Norbar multiplier with three or more stages of epicyclic gearing.
Torque control is achieved by adjustment of the air pressure. An air pressure versus torque graph and a calibration certificate is supplied with each tool and allows specific torque values to be set. For more critical applications, Pneutorques can be fitted with a torque transducer and the precise torque output displayed. The tool can then be shut off at the desired torque either manually or automatically using suitable control circuitry.
Models are available up to 100,000 N.m (73,000 lbf.ft).
Norbar's torque transducers have established an excellent reputation based on exceptional quality and accuracy. A very wide torque range is covered, 0.04 N.m to 100,000 N.m and three basic transducer configurations are offered; Static, Impulse Rotary and Annular.
All transducers up to 5000 N.m (or 5000 lbf.ft) are supplied as standard with a UKAS calibration certificate from Norbar's in-house laboratory. Larger transducers are supplied with a certificate traceable to national standards.
For customers who wish to take advantage of Norbar's transducers but have an existing, non Norbar display instrument, transducers can be provided with a mV/V calibration.
Norbar's instruments and transducers are complimented by a wide range of ancillary products. Within this group are the products that would be required to set up a torque calibration laboratory, for example, torque wrench loaders meeting ISO requirements and precision beam and weight systems for calibration of torque transducers.
Norbar manufacture an extensive range of high quality torque wrenches to cover torque values from 1 N.m to 1500 N.m. They are designed and manufactured to exceed international standards for accuracy.
In addition to the normal 'adjustable' torque wrenches, Norbar offer Production 'P' Type versions which can be pre-set and dedicated to a particular application. This setting system is designed to discourage unauthorized alteration.
All Norbar torque wrenches are offered as standard with a quality ratchet. For applications where interchangeable end fittings are required, 'Torque Handles' are also available in various models up to 550 N.m.
In certain critical bolting applications, factors such as friction or bolt/joint geometry are such that the measurement of applied torque alone will not provide the degree of accuracy necessary to control the preload to be monitored over the service life of the fastener as part of a predictive or preventative maintenance program. In these applications, ultrasonic measurement of fastener elongation and/or load has frequently proven to be the most accurate, reliable and cost effective solution.
Ultrasonic measurement of bolt preload is made possible by introducing a sonic pulse at one end of the fastener and accurately measuring the time of flight (TOF) required for the echo to return from the opposite end. Using material constants, the USM-3 converts this TOF into an "ultrasonic length" of the fastener, providing a baseline from which future measurements will be made. When the fastener is tightened, the TOF increases and the USM-3 will again utilize material constants to eliminate the effects of stress and temperature variations on sound velocity, providing an accurate elongation or load measurement.
The USM-3 uses state of the art hardware and software to achieve these measurements with maximum automation, and minimizes the need for operator interpretation. Offering digital recording and transmission of data, as well as analog signal output the USM-3 provides a complete system for measurement, recording, and control of fastener tension in the most demanding applications.
Applied measurement solutions, llc
Main Office: 46 cherry hill drive bristol, connecticut 06010
Precision Center & Show room: 28 Town forest road,
webster, massachusetts, 01570
Phone: (860) 817-0598 Fax: (860) 314-1973 Email: sales@amsgage.com
