E.T.S. corrugated steel European Tooling Systems introduces its new line of high-speed corrugated steel. E.T.S. now has a large inventory of corrugated back knives in 5/16- and '-in. thickness. The 25-in. bars come with 60-degree corrugations in a wide array of sizes. The company also offers the "back pack" knife system, consisting of an adjustable carbide blank and a steel backing plate for accurate positioning and longer life.