The Nord-Lock bolt securing system uses tension instead of friction to ensure that joints holding sub-assemblies together remain secure. Bolts on pumps need to be easily removable during maintenance procedures, but must resist the loosening effects of vibrations and dynamic loads. Bolts that are locked conventionally by friction in the thread tend to lose most of their preload through vibrations, while those locked by the tension of this system present a minor loss of preload which is caused mainly by settlement in the thread. Even after moderate tightening, the bolt is safely locked when using Nord-Lock.
It has become increasingly important to have good control of the torque-clamp load relationship when tightening a joint. To optimise the design of the joint and utilise as much of the capacity of each dimension as possible, it is important to know the required tightening torque. Nord-Lock washers, which are installed in pairs, cam face to cam face, have cams on one side, with a greater rise than the pitch of the bolt. When the bolt and/or nut is tightened, the radial teeth on the opposite side grip and seat the mating surfaces. The teeth also lock the washers in place, allowing movement only across the face of the cams. The resulting tension makes the bolt self-locking.
These washers can be used on standard grade, as well as high grade bolts and there is no need for adhesives to lock the stud bolt. This system is designed for use in tapped and counter-bored holes and for larger holes or on soft materials, a flange nut or bolt should be used in combination with Nord-lock washers with a larger outer diameter.
Advantages of this reusable system include maximum safety when locking fasteners, easy assembly and disassembly, positive locking at low or high preload levels and minimum surface marring or scratching. This system, which has the same temperature characteristics as a standard bolt or nut, resists loosening caused by vibration and dynamic loads. The locking function is not lost by lubrication.
A method for testing the security of a bolted joint is the Junker-vibration test where the preload (bolt tension) is measured by a load cell and vibrating motions are generated radically through the bolt.
Industrial gear units for mixing and agitating processes Bearing Man Group T/A BMG
Electrical switching & drive systems & components
Nord Drive Systems encompass modular drive configurations that ensure optimum performance of mechanical speed control for specific applications in almost every industry.
Read more...Bearing failure analysis is a perfect solution for Tongaat Hulett SKF South Africa
Shaft power components
A collaborative bearing failure analysis conducted by SKF and Authorised Distributor, Bearings Services Durban at one of South Africa’s leading sugar refinery plants in KwaZulu-Natal provided tremendous value for the customer.
Read more...Heavy-duty V-belts for aggressive conditions Bearing Man Group T/A BMG
Shaft power components
BMG’s specialised Gates belting range includes Predator V-belts, engineered for optimal performance in Africa’s harshest conditions.
Read more...Vibration monitoring in three axes with IO-Link ifm - South Africa
Shaft power components
Machine vibrations are important indicators when it comes to assessing the current condition of a machine. Damage to rolling element bearings and other machine components can be detected at an early stage before costly machine downtime occurs.
Read more...BMG powers up at Nampo 2025 Bearing Man Group T/A BMG
News & events
The BMG team was highly prominent at this year’s Nampo agricultural show, held near Bothaville recently. This prestigious event, which is one of the largest agricultural exhibitions in the southern hemisphere, is a highlight for manufacturers and suppliers of farming equipment, as well as for farmers, families and the entire community.
Read more...New generation low power frequency inverters Bearing Man Group T/A BMG
Electrical switching & drive systems & components
New to BMG’s electromechanical range are energy-efficient Synergy PI150 series frequency inverters, which have been designed for efficient use in many applications.
Read more...Motion technology for all types of automation Bearing Man Group T/A BMG
News & events Electrical switching & drive systems & components
BMG has been appointed by The Timken Company as a distributor in southern Africa for the Rollon linear motion guidance system.
Read more...Efficient maintenance counts Bearing Man Group T/A BMG
Shaft power components
BMG’s total plant management solutions encompass a technical advisory service for maintenance programmes that includes correct chain and sprocket selection, which is a critical factor in any power transmission system.
Read more...Optimise your plant assets SKF South Africa
Shaft power components
The SKF Rotating Equipment Performance Centre provides anyone from anywhere with easy access to a comprehensive suite of advanced condition monitoring, analytical and diagnostic solutions.
Read more...Hydraulic pumps deliver high flow, convenience and precision Bearing Man Group T/A BMG
Hydraulic systems & components
BMG’s range of high-performance hydraulic electric Enerpac E-pulse pumps is critical to all 700 bar operating hydraulic systems. These portable E-pulse pumps have intelligent auto-cycle functionality and an efficient power-to-weight ratio to ensure dependable operation and high productivity in challenging industrial applications.
printer friendly version