If the ductile grade 60-40-18 is easier to machine, why does Dura-Bar offer 65-45-12?
The heat-treat cost to achieve 60-40-18 is unnecessary in most instances. A well controlled continuous cast process, like Dura-Bar, produces 65-45-12. To achieve 60-40-18, the bars have to be annealed and that adds cost. The actually machinability between a consistently cast 65-45-12 and an annealed 60-40-18 is almost negligible. Some foundries will add a full anneal to mask or eliminate inconsistencies in their casting process, such as poor rim control, carbides and hard spots.
