Coils (threaded inserts) create high-strength joints in low-strength metallic materials and have been proven in practice for decades. HONSEL coils threaded inserts are available in a range of variants and are characterised by high wear resistance, low thread friction in close tolerances, high surface quality and outstanding corrosion and heat resistance.
HONSEL coils are made from high-quality chrome-nickel steel (X5CrNi18-10). This material grade is the precondition for threads with high load-bearing strength, wear resistance and a low and constant thread friction torque. By contrast with conventional threads, a higher and constant preload force can be achieved with the same tightening torque even with repeat tightenings. Furthermore, better use can be made of the yield strength of high-strength screws. Furthermore, the surface roughness is up to 85 % lower by comparison with conventionally cut threads.
High load-bearing strength
With conventional screw fittings, the main load is exerted on the first three threads. HONSEL coils solve this problem. The main load is distributed uniformly over the whole length of the bolt and thus leads to significantly more stable screw joints – particularly with screws subject to dynamic loads.