“There are two reasons why bolted joints normally fail – spontaneous bolt loosening, and slackening,” says Ryan Bassett, senior product manager, BMG’s fasteners, tools and equipment division. “Bolted joints in heavy industries are constantly subjected to external forces which results in spontaneous loosening, due to vibration and dynamic loads. With the development of new materials and techniques – such as corrosion resistance composites – slackening is a common problem that results from settlement and relaxation.
“Nord-Lock’s X-series washers have been designed for optimum bolt security for joints exposed to severe vibration and high dynamic loads, like those found in mining applications for instance. The wedge-effect design prevents spontaneous bolt loosening and an integrated spring effect of the system compensates for the loss of preload due to slackening.”
Each washer pair has cams on one side and radial teeth on the opposite side to secure the bolted joint with tension, rather than friction. The conical shape of these washers creates an elastic reserve in the bolted joint to compensate for the loss of preload and prevents slackening.
Advances in polymers and sandwich composite technology have the strength to weight ratio and corrosion resistant properties that make applications lighter, without losing strength. But these materials are softer than metal materials previously used and make slackening an additional challenge. The multifunctional wedge-locking concept of the X-series combats these problems.
Surface treatments, which are common for corrosion protection, can also lead to slackening as the bolt sinks into the treated surface after tightening. Even a thin millimetre surface would normally put bolts at risk, but with the compensating spring of X-series, slackening is prevented.
All bolted joints have a functional preload range in which the joint is safe. Serious problems start as soon as the preload falls outside the functional range. If the preload is too high, yielding occurs. If it is too low, there is separation or sliding between the parts.
The Nord-Lock X-series, which is quick and easy to install and remove with only standard tools, has been certified by TV, a leading international institute in quality and safety certification.
Reinstatement opportunity for ECSA registration
News
In 2023 the Engineering Council of South Africa (ECSA) announced a special opportunity for engineers in South Africa to reinstate their registration status if it had been cancelled. This exclusive offer is available until the end of August 2024.
Read more...Fuel your competitive edge with tech that transforms
News
The KwaZulu-Natal Industrial Technology Exhibition 2025, taking place from 22 to 24 July at the Durban Exhibition Centre, offers a vibrant, solution-focused platform tailored to the unique needs of KwaZulu-Natal’s industrial, manufacturing, engineering, maritime, agricultural and mining sectors.
Read more...NORD modular drives for frequently changing motor speeds Bearing Man Group t/a BMG
Motion Control & Drives
BMG has made a substantial investment over the years to ensure assembly, stockholdings and technical support for the Nord range are in line with stringent international quality, safety and environmental standards.
Read more...Schneider Electric launches first registered Innovation Hub in Africa Schneider Electric South Africa
News
Schneider Electric has officially launched its first registered Innovation Hub in Africa. This provides an interactive environment where visitors can explore the company’s integrated solutions across key segments and businesses such as energy, buildings, data centres, industrial, and power and grid.
Read more...A strategic milestone for Conical Technologies Conical Technologies
News
Conical Technologies has been appointed as the sole distributor in southern Africa for Mibbo, manufacturers of a vast array of products for the automation industry.
Read more...Robotics TechTalk at UKZN
News
The Scientific Multidisciplinary Advanced Research Technology Lab at the University of KwaZulu-Natal recently held an exciting TechTalk. It was an opportunity to introduce students to the IEEE Robotics and Automation chapter, SAIMC, and the Robotics Association of South Africa.
Read more...Schneider Electric honoured with Gender Leader Award Schneider Electric South Africa
News
Schneider Electric has been awarded the Gender Leader Award at this year’s Africa CEO Forum. This award acknowledges those organisations operating in Africa that have shown a significant and continuous commitment to gender diversity and inclusion.
printer friendly version