5.1.5 CoreFor bevel pinions, bevel

5.1.5 CoreFor bevel pinions, bevel crowns, cylindrical gears and gears in general, the core is the centre of the tooth root(mid of tooth root thickness, Figure 1, point C).In parts with both spline and involved teeth, core hardness is measured only on the involved teeth (therequirements indicated in the drawing refer exclusively to the involved teeth).For gears with a tooth root thickness less than 5 mm, the core hardness is to be measured at point D as shown inFigure 1.In case of splines with tooth root thickness greater than 5 mm, the core hardness is to be measured at point D asshown in Figure 2. If the spline root thickness is less than 5 mm, the core hardness is to be measured only if it isindicated on the drawing.For shafts with diameter up to 25 mm, the core hardness is to be measured at mid-radius. For shafts with adiameter greater than 25 mm, the core hardness is to be measured in the area shown in the drawing, at 5 mmfrom the outer diameter.