Professional Machinist Calculators
Free, accurate tools for speeds & feeds, drill depths, tap drill sizes, and more. Based on Machinery's Handbook formulas.
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CALCULATORS
Speeds & Feeds Calculator
60+ materials, HSM chip thinning, tool deflection warnings, power requirements
PRODrill Point Depth Calculator
Calculate blind hole depths accounting for drill point geometry
Tap Drill Size Calculator
Calculate tap drill sizes for UNC, UNF, and metric threads with material-specific recommendations
Stock Yield Calculator
Calculate parts per bar, waste percentage, and cost per part for bar stock optimization
Thread Depth Calculator
Calculate minimum thread engagement for tapped holes based on material combinations
Tolerance Stack-Up
Worst-case and RSS analysis for assembly dimensional variations with Cpk calculations
Surface Finish Converter
Convert between Ra, Rz, RMS, and ISO N-grade with automatic classifications
Right Triangle Calculator
Solve right triangles with any two inputs. Supports angles (decimal/DMS) and sides (imperial/metric)
PROOblique Triangle Calculator
Solve non-right triangles using SSS, SAS, ASA, AAS, or SSA methods. Handles ambiguous case with dual solutions
PROSquare Diameter Calculator
Calculate the largest square that fits in a round shaft with visual diagram showing waste area
Hexagon Diameter Calculator
Calculate the largest hexagon that fits in a round shaft with visual diagram showing waste area
Bolt Circle Calculator
Calculate coordinates for bolt circles with up to 100 holes. Solve for BC, HD, or MD. Supports D.R.O. mode
Sine-Bar Calculator
Calculate angle/height relationships for sine bar setups used in layout tables and milling vises
Chord Length Calculator
Calculate circle segment and chord relationships for keyways, arcs, and circular features
QUICK REFERENCES
LATEST ARTICLES
Machinery's Handbook
The bible of metalworking for over 100 years. Every formula, chart, and reference you need.