CNC Machinist Tools

Calculate speeds and feeds, inspect G-code with 2D toolpaths, solve threads, bolt circles, tap drills, tapers and more — all in one offline machining toolkit.

CNC Machinist Tools is an offline machining toolkit for machinists, CNC operators, students and workshop use.

Quickly calculate machining parameters, inspect local G-code files, preview 2D toolpaths, solve thread geometry, generate bolt-circle coordinates and handle common shop calculations — all directly on your iPhone.

Speeds & Feeds

Calculate RPM and feed rate for:

Milling Turning Drilling Metric and imperial units

Enter your own cutting parameters and get clear, repeatable results.

G-Code Viewer

Open local .nc, .gcode, .ngc, .tap and .txt files.

Read G-code with line numbers Search and jump to source lines View parsing diagnostics and program summaries Preview supported toolpaths in XY, XZ and YZ views Zoom, pan, fit and inspect toolpath-to-source mapping

G-code viewing is read-only and intended for inspection and reference.

Thread Calculator

Calculate theoretical thread geometry for:

ISO Metric Unified Inch Pitch / TPI Multi-start threads

Pro unlocks additional theoretical thread dimensions and formula details.

Tap Drill

Calculate theoretical cutting-tap drill diameters using metric or imperial inputs and configurable thread engagement.

Bolt Circle

Generate X/Y hole coordinates from:

Pitch circle diameter Hole count Start angle Center position Rotation direction

Copy calculated coordinates for use elsewhere.

Taper

Calculate taper dimensions, taper per unit length, half-angle and included angle, or solve for an unknown dimension.

More Workshop Tools

Drill Size Converter Unit Converter Metal Weight Calculator History Favorites Machine Profiles Machine Limits Formula Details

Metric & Imperial

Work comfortably in either measurement system, including fractional-inch display where appropriate.

Lifetime Pro

Unlock:

Tap Drill Metal Weight Machine Profiles & Limits Advanced Thread Details Formula Details Favorites Unlimited History

One-time purchase. No subscription.

CNC Machinist Tools performs calculations locally and is designed as a reference and productivity tool for machining work.