Nylon 6.6 Rod is the most popular Nylon Rod in the UK, it is often specified on engineering drawings as it is so readily available and is described as the jack of many trades.
The natural grade of Nylon 6.6 Rod is highly recognisable because of it's cream colour with the slightly darker skin. This slightly darker skin is acquired during the annealing process.
Difference between Nylon 6 & 6.6 rod
We often get asked what the difference is between Nylon 6.6 Rod and Nylon 6 Rod. Engineers tell us that the Nylon 6.6 grade is slightly harder, will machine slightly better but there is not much in it.
Because Nylon 6.6 is manufactured by an extrusion process only it means that the size range is more limited, particularly for larger sizes as it is too difficult for manufacturers to extrude large nylon rod.
Nylon 6.6 rod for food contact
Nylon 6.6 Rod natural grade is acceptable for food contact. The black grade because of it's additives is not and should be kept for more industrial applications.
Operating temperatures for Nylon 66 rod
Other differences between Nylon 6.6 Rod and Nylon 6 Rod are that Nylon 6.6 does have a slightly higher operating temperature range, so is a better option if there is a chance that the component could come into contact with heat that is just a little over the range of Nylon 6.
Nylon 6.6 Rod is slightly more expensive than Nylon 6, this is due to the polymer being slightly more expensive from the polymer producers.
Black Nylon 66 rod
The black grades or sometimes charcoal grey versions of Nylon 6.6 Rod will often contain an additive called Molybdenum disulphide or MoS2 for short. This is a graphite type material that is added during the manufacturing stage and is there as a self lubricant to reduce maintenance during service and also as a friction reducer. The overall result is that black Nylon 6.6 Rod should last longer and wear less in an industrial or abrasive environment.
Water absorption of Nylon 6.6 rod
It must be noted that Nylon 6.6 Rod can absorb moisture (hydro-scopic). What this would mean is that components or items needing a very tight and stable tolerance are subject to variation due to the environment they find themselves in. It means that a very close fit bearing may tighten up if exposed to prolonged damp or wet environments.
Nylon 6.6 for CNC Machines
Nylon 6.6 Rod would be slightly better suited to automatic CNC type machines than Nylon 6 Rod because it is slightly harder and has a higher temperature range meaning that during the machining process, slight heat build up will have less effect and the harder structure of Nylon 6.6 Rod will allow it to machine to a slightly smoother finish.