MICRO-STOP COUNTERSINKS
Included Angle 82° Included Angle 90° Included Angle 100° Included Angle 120° Body Diameter Pilot Diameter Range  List Price 
83E00002 83E00003 83E00004 83E00006 3/8 1/16-3/16 56.47
83F00002 83F00003 83F00004 83F00006 7/16 3/32-3/16 58.03
83G00002 83G00003 83G00004 83G00006 1/2 3/32-1/4 66.87
83H00002 83H00003 83H00004 83H00006 5/8 5/32-3/8 80.22
86E00002 86E00003 86E00004 86E00006 3/8 1/16-3/16 56.47
86F00002 86F00003 86F00004 86F00006 7/16 3/32-3/16 58.03
86G00002 86G00003 86G00004 86G00006 1/2 3/32-1/4 66.87
86H00002 86H00003 86H00004 86H00006 5/8 5/32-3/8 80.22

Standard pilot blend radius is .020 max.
For Pilot blend radius .020-.070 +/-.005 add 25%

How to build Tool Number for Micro-stop Countersinks
  Series Body Diameter Pilot Diameter Countersink Angle Blend Radius
  83 7/16 .1250 100° 0.025
           
Tool No. 83 F 1250 4 R.025
Tool No. 83F12504
Tool No. with Blend Radius 83F12504R.025