Using a bandsaw blade to cut a piece of material doesn’t usually cause any problems with that material. However, occasionally, the material causes significant problems for the bandsaw blade!

During the processing and manufacture of metals, heat and stress are applied to form and shape the melt, often leaving residual stresses “built in” due to quick and uneven cooling after casting, forging or rolling resulting in a difficult sawing application. Though from the outside, much of the time the material appears to be stable and still within expected dimensional tolerances, once a saw cut is made that removes (or attempts to) a significant proportion of the material, internal stresses that were balanced within the whole are free to relax and move slightly to a new equilibrium.

The upshot is that often a customer receives a deformed bit of metal, or, it has fractured where the stresses have overwhelmed the strength of the material, or worse, it jams up on the blade in the cut even before it manages to complete the cut! That can be a real headache, but nothing has defeated us yet!

Here are a few of our challenges, and the results of the release of internal stresses. Note, these stresses aren’t just revealed through bandsawing, but any machining process on a non-normalised piece of material can cause a rebalancing of the internal stress in a similar way.