Drill Part No.System
Field 1 Drill Type
G Gun drill
E Gun reamer
F Speedfeed
S Speedbit
V Ventec
P Proten
X Special
Field 2 Standard or Coated
M Standard metric
C Coated metric
I Standard imperial
K Coated imperial
Field 3-7 Diameter (Decimal point is between fields 4 & 5, size to 3 decimal places
Fields 8 Contour (Gun drills only. All other drills are 'A')
A-C1 Standard
C-C2 Cast Iron
D-C3 Gun boring
E-C4 Crankshafts, Aluminium > dia Ø 4.0
X Special
Fields 9-12 Length (No decimal point)
Gun drills Overall length
Gun reamer Overall length
Speedfeed Flute length
Ventec Flute length
Speedbit Flute length
Fields 13&14 Driver Type (See separate list for driver codes)
ND No driver
RT Re-tip
RD Reduction
RG Re-grind
MO Modification
Fields 15 Workpiece Material
A Steel/Non ferrous
H Cast Iron
T Cast Iron (high phosphorus content)
M Stainless steel, High Si content aluminium
Field 16 Nose Grinds
A NG6/NG8 Standard
B NG4 Aluminium
E NG13 Cast Iron
F NG73 Stack
G NG80 Flat bottom
H NG82 Inconel
J NG83 Crankshaft
K NG86 Wood
X Special
Example
Gundrill, Not-Coated metric, Ø8.0mm, Std contour, 400 o.a.l. C A Driver Ø 16x40mm, to cut steel, stack nose grind.