Machine tools suppliers BMG’s extensive portfolio of fasteners, tools and related equipment has been carefully selected for dependable operation, flexibility, enhanced safety and extended service life in diverse sectors. This includes light, medium and demanding applications.

The company’s range of products for the machine tools sector encompasses Nord-Lock bolt securing systems that have been designed to ensure the structural security of bolted joints exposed to strong vibrations and high dynamic loads.

“BMG’s commitment to customers is to assist in optimising inventory investment and to reduce production and maintenance costs, at the same time minimising downtime in every operation,” says BMG Nord-Lock Group fasteners division national product manager Wean Marais.

He adds that the two reasons why bolted joints normally fail, are spontaneous bolt loosening and slackening. Bolted joints in heavy industries are constantly subjected to external forces, which results in spontaneous loosening owing to vibration and dynamic loads.

“Advances in polymers and sandwich-structured composite technology have the advantage of 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 Nord-Lock range combats these problems.

“BMG’s Nord-Lock products have been specifically adapted to suit exact requirements through the use of specific materials, hardening treatments, surface coatings and the correct tolerance for each application.”

Nord-Lock wedge-locking technology ensures optimum bolt security. These products include Superbolt multi-jackbolt tensioners, which are designed for applications requiring a high clamping force and for tasks with limited space for tightening bolts.

This quick and efficient bolting method is based on a design which splits one large torque into a number of smaller ones.

BMG’s multi-jackbolt tensioners, which replace or retrofit nuts and bolts, ensure joints can be tightened with high accuracy without the need for specialist skills or heavy tooling. Tightening in pure tension allows higher preloads on the same size bolt than conventional tightening methods.

Multi-jackbolt tensioners are easy to install, even in confined spaces. While there are multiple jackpoints to tighten - by using hand or air tools – installation times are faster than other bolting methods.

The high preload capacity and accuracy of this system has resulted in the design of smaller bolt sizes. Compact dimensions and decreased tooling sizes allow for a reduction in the size of machinery, reducing material and machining costs.

The X-series washers, which are quick and easy to install and remove with standard tools, have a wedge-effect design that prevents spontaneous bolt loosening. An integrated spring effect of the system compensates for the loss of preload owing 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.

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.

The combined tension and spring action of X-series washers combats the effects of surface treatments, thermal cycling and vibration.

BMG’s portfolio of Nord-Lock bolt securing products includes robust wheel nuts, designed to safely secure wheel joints on both on-road and heavy-duty vehicles – even under severe conditions.

The Nord-Lock wheel nut, which uses tension instead of friction to secure bolted joints, offers a reliable solution to wheel nut loosening. This system does not rotate loose and safely secures the wheel joints on roads and in harsh off-road operating conditions.