Premature and uneven barrel wear is expensive in terms of both replacement costs and lost process efficiency. Reiloy Westland Corporation barrels are lined with an A-11 tool steel for exceptional longevity and uniform wear. For low abrasion applications, we keep your costs down by using D-2 tool steel. Please refer to the Barrel Material Guideline table.
PM10V is a particle metallurgy tool steel that is heat treated to Rc 62-64. It offers a microstructure with vanadium carbides from its nearly 10% vanadium content which makes this steel one of the most abrasion resistant materials available.
D-2 is a tool steel heat-treated to Rc 58-60. It is a relatively inexpensive, high carbon – high chromium steel with proven, uniform wear resistance surpassing most other steels.
Nitrided barrels may be made from 4140 but a nitriding steel, such as Nitralloy 135M enables a better nitrided interior surface to be achieved.
Gas Nitriding is used to create a surface hardness on the barrel. The hard layer of steel will vary in depth from .007” to .015” depending upon the length of the nitriding cycle. The hard layer (usually well above 60 Rc) is achieved by heating the steel in an atmosphere of nitrogen (ammonia gas) at temperatures of 950 to 1050 degrees F. The nitrogen atoms are diffused into the surface of the steel, combining with nitride-forming elements, such as chromium, aluminum, molybdenum, vanadium, tungsten and titanium, to produce a very hard surface, particularly for the first .002” to .005” depth. Nitrided barrels have a very good wear resistance until the surface hardness is worn away. After the surface is worn .007”, wear accelerates and the barrel may quickly be worn to a condition that is beyond repair.
Nitrided barrels are not recommended for use with abrasive or corrosive resins because of their inability to resist wear over an extended time period.