PTFE Coated Fasteners

Teflon® and Xylan® coatings for fasteners meet the concerns from engineers on the subject of corrosion. The damage caused by corrosion has both a direct cost and an indirect cost to engineering companies in the gas and oil and exploration sector, it is for this reason PTFE coatings are emerging as an innovative alternative to corrosion protection. Testing has indicated that the future for PTFE coatings for fasteners not only demonstrates the value of corrosion protection, but PTFE coated fasteners can be easily disassembled. The formulations of modern PTFE coatings offer high performances due to the addition of fluorine, the most electro-negative element and the most reactive non-metal, its atomic radius is the smallest next to hydrogen. Other major benefits of PTFE coatings for fasteners include non-stick, electrical resistance, low friction and abrasion resistance. 

The range of fasteners that benefit for PTFE coatings include studs, bolts, nut and washers in various materials, these include high tensile, stainless steel and forged materials. Previously, hot dip galvanising, cadmium or zinc plating were considered standard, however, with the performance factors that include low coefficient of friction and corrosion resistance, PTFE coatings offer enhanced performance characteristics that includes consistency of tensioning and subsequent ease of installation and removal. An additional benefit of PTFE coatings for fasteners is the availability of colours, this is most effective for product identification and to identify torque loading limits for differing applications. Nut and bolt connectors life expectancy and corrosion resistance improve dramatically when PTFE coatings are applied. 

Tests have shown that on a series of torque to load applications, PTFE coated fasteners showed a reduction of makeup torque loads with greater lubricity, without loss of structural performance. PTFE coatings on fasteners, is on the rise, whereas most other surface treatments generally provide only limited performance. PTFE formulations include binder resins, holding the fluoropolymers in place, as well as providing reinforcement. The level of PTFE relative to the binder resin determines the lubricity of the applied coating and PTFE does not impact upon the corrosion and chemical resistance. 

As far back as the early seventies, PTFE coatings were used on fasteners to provide torque control and providing an advantage over cadmium plating to maximise the performance of fasteners. Today, with the revised formulations designed to meet the challenges of corrosion resistance, many design engineers now make PTFE coatings the ideal choice for fasteners.