Supplier Variation: Why Different Steel Batches Drill Differently
The Reality of Material Variation I have seen the same steel grade from the same supplier drill differently from batch to batch. The chemistry is the same on the cert, but the material behaves differently on the machine. This is not a defect — it is a reality of steel making. Steel production is not perfectly repeatable. The melting temperature varies slightly, the cooling rate after rolling varies, and the chemistry has allowable ranges within the specification. These small variations add up to measurable differences in machinability. ...