For all of my combine and header chains, as well as cutter bars and as a winterizing overspray, I use chain [saw] bar oil (any brand really, whatever brand I find, where ever I find it, it's all the same). Chain bar oil is not only comprised of oil, but oil with an adhesive_tacking additive which makes it remain on the surface longer under high RPM operations. Chain bar oil also contains anti-wear agents, which are perfect for cutter bars. During harvest, I spray my gathering chains and cutter bars at the end of each day with a 50_50 solution of chain bar oil and diesel fuel (the only reason I cut it is so that it will go through my hand held weed sprayer) to prevent green_wet material from adhereing to the cutter bar and moisture from penetraining surface areas or chain joints. Takes only minutes to apply. Chain bar oil works perfect as a winterizing overspray, especially on blades and buckets exposed to road salt or even blades, buckets, metal surface areas exposed to manure or other waste or fertilizers containing salt_sodium. Chain bar oil will keep the rate of N corrosion to a crawl too.