01-28-2015, 06:58 AM
Cast iron grade, and a very hard, wear resistant one at that. It'll take you a lifetime of abusing them to use up the 40 corners, so no worries.
You mostly use the long edge of the insert for the chamfers anyhow so the bigger corner radius is of little consequence. It only makes a difference when you have a short shoulder (low size differential between the two diameters) that the sharper corners help.
You mostly use the long edge of the insert for the chamfers anyhow so the bigger corner radius is of little consequence. It only makes a difference when you have a short shoulder (low size differential between the two diameters) that the sharper corners help.