Author: A.G. Russell
Blades have been coated in one form or another at least from the middle ages. The earliest I know of is rust bluing that would have been used to help reduce rusting and also for beauty especially where gold or silver was inlaid into the blade.
An early replacement for bluing is the Parkerized finish developed for the protection of stocks of rolled steel stored in the open, it began to be used early in this century as less expensive and more suitable to rough military finishes than bluing. This was as true of bayonets and combat knives as it was of guns. The only real excuse for use of that coating today would be to kill reflection. It is not a good coating for cutting as anything you cut will stick and not slide across the finish. As soon as the electro-plating process was developed, people began plating knife blades with gold, silver, chrome, and probably as many other elements as they could think of both-to keep them from rusting and for beauty. While stainless steel was developed about 1910, there was no useful high-carbon stainless available to the knife industry until the 1960s so some makers used plating, like Gerber's hard chrome, to keep rust down. The problem was that the sharpened edge rusted and most people would rather have a knife that did not hold an edge like the high-speed Gerber blades but did not rust. So Gerber went to less expensive stainless and the customers were happy and Gerber made lots more money. If you can find the old high-speed steel kitchen knives put them to work in your kitchen, they will have rusty edges, so what?.
Some time in the 1930s or 40s, Robeson Cutlery offered hunting knives with tungsten carbide coated on one side of the blade. The idea was that the softer steel would wear away and the knife would never need to be sharpened. This idea was ahead of it's time.
In the 1970s some knives were plated with black chrome, gold chrome and coated with Teflon® of various colors. The black and gold chrome were actually plated into the surface of the steel and stood up quite well under light use. The Teflon®: when done right was really sturdy and stood up to extremely hard use.
The newest and toughest of all plating is the titanium nitride plating or coating which has been available to some extent for the past ten years or more. Many people thought that plating a sharp knife with this material would insure that it would stay sharp for a long time. The problem is that plating makes it less sharp. When sharpening you remove the coating from both sides of the edge, exposing the steel so that nothing is gained. Buck's new process is very like that of Robeson in the 1940s, in that the knife is sharpened only on one side and relies on the hardness and wear resistance of the titanium nitride to keep the knife sharp. This works, at least in the short term. Time may show that it will work in the long term as well. My tests have been positive enough that I will be recommending some of these Buck knives to my customers. For this to work YOU MUST NOT sharpen the other side of the edge. The titanium is of course fully rust resistant.
The newest coating in the knife industry is the Black-T®, this is a VERY well done Teflon® coating developed for the arms trade and with wide industry uses. It is the toughest Teflon® finish I have ever seen, even tougher than the great hostaflon finishes we put on our Sting™ in Germany. While Teflon® has been available on knives for over 20 years this new method seems to be a lot better than any use of it I have seen before. This finish is being offered on a few of the Benchmade knives and is being looked at by all of the other knife companies. This process is extremely complex and the developer, Mr. Walter Birdsong tells me that they will coat your entire pistol, rifle, shotgun (except the bore). All internal parts will be forever protected from rust. Mr. Birdsong can be reached at 601-939-7448.
Teflon® and Black-T® are Registered Trademarks of their respective owners.
Source: rec.knives Newsgroup