Yes, most custom gears manufacturers offer or subcontract a range of coatings and surface treatments, though they often do not perform these in-house. Common treatments include zinc phosphate (rust prevention and break-in lubricant retention), black oxide (corrosion resistance), manganese phosphate (improved wear resistance and oil retention), nickel plating (corrosion and wear resistance), PTFE (Teflon) or MoS₂ coatings (dry lubrication for low-speed, high-load applications), and DLC (diamond-like carbon) coatings (high-performance friction reduction).
However, you should be aware that coating application nearly always involves a third-party vendor, which introduces additional quality control challenges and lead time. Typical coating turnaround adds 3–7 business days beyond gear completion, but specialized coatings (e.g., aerospace-grade DLC) can take 2–3 weeks. It is essential to specify the coating thickness and adhesion requirements on your drawing, as excessive thickness can alter tooth geometry, affecting backlash and contact patterns. Also, grinding is usually done after heat treatment but before coating—coating thickness must be accounted for in final dimension calculations. For high-precision ground gears, you should request a coating inspection certificate (adhesion test, thickness measurement, and salt spray test) with the shipment. Some manufacturers offer a “turnkey” service where they manage the entire coating supply chain, while others expect you to arrange coating separately—always confirm this upfront.