Nylon is a thermoplastic. Meaning its chemistry does not change when it is melted to the metal part. Nylon will melt and re-melt if the metal part is heated again.
Nylon coating powder is aesthetically attractive when applied properly but is never specified simply because it looks good. Costing more than 3 times the typical paint or powder finish, nylon is specified for functionality IE: slip, sound dampening, flange linings, and medical case brackets. Other types of parts we apply nylon to are: drive splines, glove box strikers, door strikers, seat springs, and various clips and clamps used in the aerospace and auto industries.
Nylon powder for use in coating metal can be purchased in two chemistries: nylon 11 or nylon 12. What is the difference? The chemist may argue there are plenty of differences, however, practically speaking Nylon 12 is slightly less hygroscopic than Nylon 11 (less than 1%) Nylon 12 typically will have lower gloss, and nylon 12 may be slightly less expensive to purchase depending on the amount ordered.
When buying nylon, gloss can not be specified. Generally, nylon 11 is around 70 gloss. Nylon 12 is typically 30 gloss. Gloss level will be the same batch to batch, and will only vary depending on the manufacturing process.
Nylon is considered a "softer" coating, easily machinable, but can not be easily marked with a fingernail.