The curve is selected based on ANSI/AGMA 2101-D04 Figure 14. The following arrangements are available:
- Core hardness 250 HB (general design purposes) = Curve 1
- Core hardness 250 HB (high quality materials) = Curve 2
- Core hardness 300 HB (general design purposes) = Curve 2
- Core hardness 300 HB (high quality materials) = Curve 3
- Core hardness 350 HB (general design purposes) = Curve 3
- Core hardness 350 HB (high quality materials) = Curve 4
- Core hardness 400 HB (general design purposes) = Curve 4
- Core hardness 400 HB (high quality materials) = Curve 5
High material quality refers to ANSI/AGMA 2101-D04 Section 16.1.