In July, US-based mining products manufacturer Excel Foundry & Machine introduced the UltraNut and the UltraBolt – a jack bolt tensioning series designed specifically for locking nuts and bolts on cone and gyratory crushers.

The series was developed in response to repeated requests from Excel’s customers for a better locking nut arrangement to secure the mantle to the head assembly. The original design required the use of a slug wrench to tighten the nut to a torch ring and manganese steel mantle. This tightening action forced the mantle downward, securing it to the concave seating surface on the head.

Removing a worn mantle is also difficult, as the crushing action over the life of the mantle causes a self-tightening rotation of the mantle, torch ring and locking nut. This self-tightening action greatly increases the force between the threads of the locking nut and the head stub, making it virtually impossible to loosen the locking nut without cutting the torch ring, which is time consuming and can cause damage to the head.

Initially, the UltraNut was meant to eliminate the use of a heavy pendulum-swung hammer or other violent and dangerous methods to loosen the head nut when changing a liner. This new design eliminates the need for a torch ring and the oxyacetylene torch-cutting when undertaking liner changes. It also eliminates the physically demanding and potentially unsafe ‘slug wrench’ method of removal.

Further, the UltraNut offers significant advantages in light of the inherent safety concerns of flame cutting steel. The AR400 steel sleeve helps protect the locking nut from wear and assists in keeping dust out of the jack bolts and head nut threads during normal operations. A silicone rubber gasket is also included to extend the life of the locking nut by protecting head threads from dust.

It was originally developed for the company’s MP Series cone crushers and is available for the MP800, MP1000 and MP1250. The UltraBolt is designed for Excel’s HP Series of cone crushers and uses the same jack bolt tensioning system as the UltraNut. The UltraBolt can replace the conventional locking bolt design in the HP Series and is available for the HP500, HP700 and HP800.

The product is currently being trialled in the US and Excel is optimistic about its reception by the market.

Excel says customer response has been overwhelmingly positive since the launch of the products. “Currently, our engineering team has several new UltraNut assemblies to design to meet the demands that the market is clearly expressing through the [requests] we are receiving. “This is going to be a very popular product for us but, more importantly, effective for our customers,” says Excel global sales director Chris Toews.