This information is pertaining to Cond B or Cond S materials, or higher strengths. These strengths are also sometimes referred to as HPA Strength Levels 1, 2, 3, 4 or 5 which cover a broad range of properties for the Nitronic grades. These strength levels developed by High Performance Alloys help to define the product properties delivered to customers. These strength levels help to convey the minimum properties that should be expected.
Low Distortion High Strength ( LDHS ) bar
Problem: Distortion occurs on high strength Cond B/S bars when material is removed through grinding or machining. Normally it is a constant battle, going from the grinder to the straightener in a continuous cycle until the desired dimensions are reached.
Explanation: The typical processing of these materials creates a natural twist in the materials. While the grains are elongated in both of these types of processes, there are axial loads that are uneven through the length. The effect of these stresses are normally not seen until another operation is performed on the material, normally machining. As the cross section is removed, those stresses are no longer balanced. These unbalanced loads will sometimes give a corkscrew appearance to the product as it is unraveled. This unraveling creates issues with straightness, dimensional tolerances and extra work for the processor to keep the product straight enough to continue.
Solution: The processing performed in our Tipton plant provides a Low Distortion High Strength (LDHS) bar. Products made through the LDHS process will not be subject to the same types of unraveling you can see through those other processes. The processing that HPAlloys provides will dramatically lessen the effects of the corkscrew and therefore reduce the extra man hours required to process to a finished part. The next time you need to order from HPAlloys make sure to ask for the LDHS version of your material. We specialize in the NITRONIC grades and the Nickel alloys, as well as the impossible (large diameter Cond B 304 and 316).