Since the first use of Mayer Rods in 1905, it has been consistently among the most widely used web-coating methods. Even in 2016 with new methods, such as slot die & curtain coating, it is an effective coating method. The reason for this has been an ongoing technical improvements.
First: The original rods that Mayer made were mostly carbon-steel rods wrapped with piano or music wire. Music wire is a high tensile strength, high carbon-steel wire. To avoid any "falseness" in tone (for music applications), its diameter must be held to less than 0.0003 in. The only downside is that it will corrode when used in most coating applications. The rod would have to be coated in oil immediately after manufacture or else it would start corroding by the time it was shipped. Before use, the oil or anti-corrosion coating would have to be removed before the rod could be used on a coating machine. Less than perfect cleaning procedures would degrade the coating. This was replaced with stainless-steel wire that would not corrode as it is made of type 304 or type 302 stainless. These stainless grades hold their size and even though they are not as hard, they wear well. Over the years, the quality of stainless grades has improved to the point where its diameter tolerance is every bit as good or better than that of music wire.
Second: As more converters found that they were applying more and more abrasive coatings, they found that replacing a $20 rod was more practical than replacing an expensive gravure cylinder or coating roll, so hard chrome plating a small-diameter rod was perfected. Hard chrome plating can increase the life of a coating rod by 300 to 500%. Hard chrome plating tolerances have also improved.
Third: As customers reduced their tolerances and demanded higher-quality products from the converters, the converters demanded higher quality and tighter tolerances from their suppliers: tighter tolerances from paper and film suppliers and the same improvements from equipment and parts suppliers. The Mayer Rod has been subject to the same demand for improvements. Manufacturing processes have improved over the years as electronics and computing applications have improved. All these have been used to make the end product better.
Fourth: Ancillary equipment has also improved. UHMW and Delrin have replaced steel and brass in rod beds, and many users of 3/8-in. and larger diameter rods are finding that rewinding the rods can reduce costs and waste.