Twist drill properties

A twist drill produces round holes. CAM Assist needs its diameter, reach and point geometry to plan drilling cycles and breakthrough.

ℹ️ Every tool also shows Name, Description, Tool type, Allowed uses and Allowed stock materials above the geometry sections — see the overview.

Use this key to understand what each input value controls on the drill. 1. Diameter (DC) The full diameter of the drill. This is the cutting diameter. 2. Usable length (LU) The flute length or maximum drill depth. This is how far down the drill will be able to cut. Usable length (LU) represents the flute length and determines the maximum drilling depth. If the drill cannot reach the bottom of a hole or the desired depth, it is typically because the usable length is insufficient. 3. Tip Mode The drill tip style. Point length: Adjusts the axial length of the drill point. The software automatically modifies the included point angle (SIG) to achieve the selected point length. Point angle: Sets a fixed included point angle (SIG) for a traditional conical tip. 4. Point angle (SIG) The included tip angle of the drill point (only used when Point angle Tip Mode is selected). 5. Overall length (OAL) The full physical length of the drill from the tip to the machine-side end. 6. Connection diameter machine side (DCONMS) The diameter of the shank that fits into the holder or spindle. 7. Protruding length (LPR) The length the drill protrudes from the holder in an assembly (stickout). 8. Face effective cutting edge count (ZEFF) The number of effective cutting edges on the drill face. For standard drills this is 2.

 

Main cutting geometry

Diameter DC	The drill diameter; sets the hole size and is a primary driver of feeds and speeds.
Usable length LU	The flute (usable) length, which sets the deepest hole the drill can produce.
Tip mode	How the point geometry is defined: by Point length or by Point angle. The matching field appears below.
Point length PL Point length	The axial length of the drill point.
Point angle SIG Point angle	The included angle of the point (e.g. 118° or 140°). Affects thrust, centring and the shape of the hole bottom.
Face effective cutting edge count ZEFF	Number of cutting lips at the point (typically two). Scales the feed rate.

Non-cutting geometry

Overall length OAL	Total length from the holder face to the tip.
Connection diameter machine side DCONMS	The shank/connection diameter where the drill meets the holder.
Protruding length LPR	The drill's default protruding length (stickout); assemblies can override it.
Shank mode	Basic for a simple shank, or Advanced for a stepped body profile (body segments) when the body isn't a simple cylinder.

Tool materials

Tool material BMC	The drill substrate (e.g. carbide, HSS).
Coating property CTP	Whether the drill is coated.
Coating COATN	The coating name/designation, if any.
Grade identification GRDID	The manufacturer's grade.

Supplementary cutting geometry

Flute helix angle FHA	Helix angle of the flutes; affects chip evacuation.
Coolant supply CSP	Whether the drill has through-tool coolant (important for deep holes).
Connection code type machine side CCTMS	Standardised connection/interface code on the machine side.

Optional details

Manufacturer BRAND	Tool maker.
Manufacturer part number DES	Catalogue/part number.
Flute length LCF	Length of the fluted (chip) section.
Shank length LS	Length of the shank.
Clamping length machine side LSCMS	Length clamped in the holder on the machine side.
Functional length LF	Functional length of the drill.
Tool assembly length LTA	Overall length of the assembled tool.
Face effective cutting edge count NOF	Number of effective cutting edges/flutes.
Usable length diameter ratio ULDR	The ratio of usable length to diameter; a measure of how slender (and deep-hole capable) the drill is.