Free machining calculators for the shop floor
Speeds and feeds for milling, drilling and turning, tap drills, bolt circles, thread wires, ISO 2768 tolerances, part pricing and a 3D-printable drill holder generator. Runs in your browser.
Milling speeds and feedsRPM, feed rate and metal removal for end mills, with chip thinning.Drilling speeds and feedsRPM and feed for a drill, and how long it takes to reach depth.Turning speeds, feeds and surface finishLathe RPM, metal removal and the theoretical finish from feed and nose radius.Tap drill calculatorThe drill for any thread and percentage, with the nearest real drill sizes.Bolt circle calculatorX/Y coordinates for holes equally spaced on a circle.Thread measurement over wiresThree-wire measurement for 60° threads, with the best wire size.ISO 2768 general tolerance calculatorThe ± tolerance a drawing's "ISO 2768-m" note allows for any dimension.Drill and end mill holder STL generatorA 3D-printable holder for a whole drill or end mill set, sized to your printer.Machined part cost and priceWhat a batch of machined parts costs, and the price per part at your margin.ISO fit calculator (hole and shaft tolerances)Limits for H7/g6, H7/p6 and other ISO 286 fits, with clearance or interference.True position calculator (GD&T)Position from measured X/Y deviations, with MMC bonus tolerance and pass/fail.Bar stock weight and material costWeight and cost of round, hex, flat and tube stock in 24 materials, with cut allowance.Countersink and chamfer depth calculatorHow deep to go for a countersink diameter at 82, 90, 100 or 120 degrees.Sine bar calculatorGauge block stack height for any angle, or the angle a stack gives.3D print filament weight, length and costGrams per metre for 1.75 and 2.85 mm filament, and what a print costs.Starting cutting speeds by materialConservative surface speeds for HSS and carbide tools.Drill size chartFractional, number, letter and metric drills in inches and millimetres.Tap drill chartCommon UNC, UNF and metric threads with the drill for about 75% thread.ISO 2768 general tolerance tableLinear dimensions, radii and chamfers for classes f, m, c and v.ISO fits and tolerance grades tableIT5-IT11 tolerance grades by size, and the ten preferred hole-basis fits.Material density chart for machining stockDensities of 24 common bar-stock materials in g/cm³ and lb/in³.How to get a machined part quoted fastWhat to send a shop, and the design choices that drive the price.