CNC Milling Program Builder | G-Code Generator

Milling Operations Overview

Operation	G-Code	Description	Key Parameters
Spot Drill	`G81`	Create starting point for drilling	Depth, Feed
Drill	`G81`	Standard drilling cycle	Depth, Feed, Retract
Peck Drill	`G83`	Deep hole drilling with retract	Total depth, Peck depth, Dwell
Tap	`G84`	Threading with tap	Pitch, Depth, Speed sync
Rigid Tap	`G84.2`	Synchronized spindle tapping	Pitch, Depth
Bore	`G85/G86`	Precision boring cycle	Depth, Feed, Dwell
Ream	`G85`	Hole finishing with reamer	Depth, Feed
Face Mill	`G01`	Surface facing operation	Width, Stepover, Depth
Pocket	`G12/G13`	Material removal from cavity	Dimensions, Depth, Stepover
Contour	`G41/G42`	Profile milling with compensation	Profile path, Offset
Thread Mill	`G02/G03`	Helical thread milling	Diameter, Pitch, Depth

End Mill Types

Square End Mill

Sharp 90° corners
Slotting, profiling, pocketing
2-4 flutes common

Ball Nose End Mill

Hemispherical tip
3D contouring, finishing
Scallop height control

Bull Nose (Corner Radius)

Rounded corners
Stronger than square
Better surface finish

Roughing End Mill

Serrated flutes
High MRR
Chip breaking geometry

End Mill Specifications

Parameter	Description	Common Values
Diameter	Cutting diameter	3mm - 50mm
Flutes	Number of cutting edges	2, 3, 4, 6, 8
LOC	Length of cut	1×D to 4×D
OAL	Overall length	38mm - 150mm
Helix Angle	Spiral angle of flutes	30°, 35°, 45°
Shank	Holder interface	Weldon, ER collet

Drilling Tools

Tool Type	Application	Speed Range	Notes
HSS Twist Drill	General purpose	15-30 m/min	Lower cost, regrindable
Carbide Drill	Production drilling	60-120 m/min	Higher speed, longer life
Indexable Drill	Large holes, high MRR	80-150 m/min	Replaceable inserts
Center Drill	Starting holes	20-40 m/min	60° or 90° point
Spot Drill	Precise start point	30-50 m/min	90°, 120°, 142° points
Reamer	Hole finishing	8-15 m/min	H7 tolerance capable
Tap (Cut)	Thread cutting	5-15 m/min	Requires chip clearance
Tap (Form)	Thread forming	10-25 m/min	No chips, stronger threads

Speeds & Feeds

Surface Speed by Material

Material	HSS (m/min)	Carbide (m/min)	Feed/Tooth (mm)
Aluminum 6061	150-300	300-1000	0.10-0.25
Mild Steel	25-40	100-200	0.08-0.15
Stainless 304	15-25	60-120	0.05-0.12
Tool Steel	10-20	50-100	0.05-0.10
Cast Iron	20-35	80-150	0.10-0.20
Titanium	10-20	30-60	0.05-0.10
Brass	80-150	200-400	0.10-0.20
Plastic	100-300	200-500	0.15-0.30

RPM Formula: RPM = (SFM × 1000) / (π × D)
Feed Rate: F = RPM × Flutes × Feed/Tooth

Workholding

Machine Vise

Standard 4", 6", 8" widths
Precision ground jaws
Kurt-style most common

Toe Clamps

Direct table clamping
Flexible positioning
For large/odd shapes

Rotary Table (4th Axis)

A-axis rotation
Indexing or continuous
Horizontal or tilting

5-Axis Workholding

Dovetail fixtures
5-axis vises
Minimal obstruction

5-Axis Programming

RTCP / TCPM

Rotary Tool Center Point (RTCP) or Tool Center Point Management (TCPM) maintains the tool tip position as rotary axes move.

Controller	RTCP/TCPM Code	Cancel Code
FANUC	`G43.4 Hxx` or `G43.5 Hxx`	`G49`
Siemens	`TRAORI` / `TCARR`	`TRAFOOF`
Haas	`G234` (TCPC)	`G49`
Heidenhain	`M128`	`M129`

Tilted Work Plane (G68.2)

G68.2 rotates the coordinate system to machine at an angle.

FANUC Format:
G68.2 X0 Y0 Z0 I_angle J_angle K_angle
Where I = rotation around X, J = around Y, K = around Z