MANUFACTURING TECHNOLOGY

New developments in heat treating equipment

Tim Donofrio, product manager, standard and aluminium equipment, CAN-ENG Furnaces International Ltd

The heat treating of high volume, mass produced high integrity threaded fasteners has been an environment where market demands for product quality standards, delivery and costs have grown exponentially over the last decade. Adages or expressions like “lighter– stronger-faster”, “value added services” and “doing more for less” are all common within the walls of high-volume fastener manufacturing facilities.

T

hese pressures have forced manufactures to seek out new and creative methods for improving their competitive position. One area where there has been significant improvements made and new developments

commercialised is with the systems used to heat treat these often “safety critical” threaded fasteners.

Background The methods for heat treating threaded fasteners have evolved

significantly over the years. Ferrous threaded fasteners were once processed in systems that evolved to include small capacity shaker hearth and rotary retort systems. As production capacity and size range flexibility became more important, manufacturers gravitated towards high capacity continuous belt style furnaces. Today these same manufacturers routinely choose continuous mesh belt heat treating systems for the many benefits they offer. In addition to ferrous fasteners it would be remiss if I did not touch on non-ferrous (aluminium) fastener processing, whose

volumes have continue to grow as a result of new automotive powertrain and magnesium component developments. Their exacting quality and volume requirements were traditionally well managed using straight forward batch heat treatment systems. However, because of the continued growth in automotive applications these aluminium fasteners are now more commonly processed using higher volume continuous belt heat treatment systems. Given the processes used to heat treat vary widely between ferrous and non-ferrous (aluminium) fasteners this article will focus on the new heat treatment system developments associated with the processing of ferrous fasteners.

Today’s environment Today most high volume manufacturers of fasteners utilise

fully integrated continuous heat treatment systems. These systems are highly automated systems requiring minimal operator involvement following the bulk loading of dunnage containers to the entry of the system. CAN-ENG Furnaces International has led in the movement to further improve these heat treating systems in an effort to not only meet the quality standards required by customers but to also improve upon their operating efficiency, which in turn improves their competitive advantage.

Improvements in manufacturing processes

Reducing part damage during processing As part of CAN-ENG’s continuous improvement initiatives, it has focused on integrating mesh belt conveying technology

112 Fastener + Fixing Magazine • Issue 68 March 2011