Back to the Future - A Tale of Two Lawnmowers

The evolutionary journey of EJOT's PT screw generations.

The benefits to customers which result from the continuous evolution of EJOT fasteners may not always be obvious, but one new specification by an internationally renowned garden equipment manufacturer provides a unique insight.

2013: The story begins with the DELTA PT & ALtracs Plus

The story began 10 years ago when our Application Engineering Team was tasked with providing a suite of fasteners for new gardening products under development by one of the country’s leading household brands and manufacturers of power tools. At the time, it was developing three ‘professional grade’ machines powered by rechargeable lithium-ion batteries – a lawnmower, a brush cutter and a hedge trimmer.

EJOT proposed three of its fasteners for the new products. The DELTA PT screw used in conjunction with DELTAsert, an insert for providing a secure fixing point in plastics, and ALtracs Plus, a thread-forming screw for light alloys.

ALtracs Plus was ideally suited to this kind of application because of how it can deliver time and cost-saving potential versus metric screws. It is designed specifically for direct thread-forming assembly into cast holes, providing maximum high-strength values in light alloy assemblies and other non-ferrous metals such as zinc, copper or brass. 

Importantly, it enables real-time cost savings by removing processes such as drilling, thread cutting and cleaning. And the screw’s unique optimised thread geometry and conical thread-forming zone provides the option to use smaller, shorter screws, where required, without compromising its ability to provide consistently high strength values and high vibration resistance.

After EJOT UK’s successful demonstration of the benefits in testing, four sizes of ALtracs Plus were specified for use across the three products. It was the perfect companion for the DELTA PT, which at the time, was the latest generation of EJOT’s pioneering PT screw. This product helped to accelerate to the widespread use of thermoplastics in manufacturing of a wide range of consumer goods and vehicles in the 1970s. It was selected by the designers for these applications for three key reasons.
 

2023: The story continues with the EVO PT

Fast forward to 2023 and those same benefits – plus others – are now being realised by a European giant within the power tool manufacturing sector, this time using the newest generation of the PT screw – the EVO PT.

EVO PT is EJOT’s latest screw designed for direct fastening into plastics, offering additional advantages that complement those offered by DELTA PT. Through its enhanced thread form geometry and special lead-in feature, EVO PT provides consistent torque regardless of installation depths, making its use straightforward and efficient because uniform tightening torque can be used for different screw lengths.

These advantages, along with EVO PT’s effective suppression of vibration during insertion and the ability to provide a high clamp load in the latest generation of plastics, offered this customer the potential to balance production efficiency with quality extremely well for its new products.

EVO PT was specified during the development of the manufacturer’s next generation lawnmower range, which includes four models. Their requirement was for high-performance screws to securely attach components including engine holders and housings, handlebar panels and gearbox covers.

Whilst the customer was satisfied with the mechanical performance of the screws they had been using in the manufacture of its lawnmowers to that point, EJOT was able to demonstrate that using the EVO PT screw in various areas of assembly could provide considerable savings whilst maintaining the high quality associated with this brand.

The EJOT team proposed a specially modified version of the EVO PT which it could show would reduce the number of variants of screw lengths needed by 50%. As a result, the customer was able to reduce parts on the BOM, meaning less storage complexities, and a reduction of installation tooling and programs – this is due to EVO PT’s installation torque being the same irrespective of screw length.

The remarkably similar stories of these two different garden equipment manufacturers – both of whom are two of the world’s leading brands in their market – helps to reinforce the case for continuous development of fastening products to keep pace with the adoption of new materials, as well as new expectations in terms of manufacturing efficiency, cost reduction and product quality.

It is also a testament to the original philosophy of the EJOT PT which was always considered to be a platform that could evolve with the market and customer demands. From its early days being regarded as the go-to solution for applications of the day such as attaching the cathode ray tubes in early generation televisions, to today’s deployment in advanced industries including electric vehicle manufacturing, the PT screw continues to lead the market.