7.6 Chisel Shaped Stylus - A chisel shaped stylus must be used in place of the standard spherical shaped stylus to check surfaces designated with the chisel stylus designation as shown in Figure 4. The maximum width of the chisel stylus is 1.60 mm (.063 inch) and the tip radius is 0.0125 mm (.0005 inch). Other details of the stylus must be in accordance with ANSI B46.1. The direction of stylus trace shall be in the direction giving a maximum reading.