Hole Machining Specifications

Friction Drilled/Tapped Holes
No. Standard Part Standard Value Example
1 Flange thickness 1/2 of plate thickness (reference value) Example
2 Flange height Equal to plate thickness (reference value)
Countersunk Holes
No. Nominal Diameter M3 M4 M5 M6 M8 M10 M12 M14 M16 Example
1 Countersink Diameter (D) Standard Dimensions 6.3 8.3 10.4 12.5 16.5 20 24.5 28.5 32.5 Example
Maximum 6.9 9.6 11.1 13.3 17.8 22.4 26.5 30.5 34.5
2 Pilot Hole Diameter (d) Standard Dimensions 3.5 4.5 5.5 6.5 8.5 10.5 12.5 14.5 16.5
Maximum 4.3 6.4 8.0 9.9 13.8 14.2 14.5 16.5 18.5
3 Countersink Height (t) Reference Dimensions 1.5 2.0 2.5 2.9 3.8 5.1 6.0 7.0 8.0
  • *Will be manufactured so that the head section does not protrude when using hex-socket countersunk bolts (JIS-B1194).
  • The screw will be threaded through to check that it is the correct size.