Engineering Tools for Machinists

Free calculators and reference charts for CNC machining and mechanical design: metal weight, ISO 286 fits, tap drills, cutting speeds and anodizing allowances.

Metal Weight Calculator

Calculate the weight of round bar, hex bar, square bar, plate and tube in aluminum 6061/7075, steel, stainless steel, brass, copper and titanium. Metric and imperial units.

ISO 286 Tolerance and Fit Calculator

Calculate hole and shaft limits for ISO 286 fits such as H7/g6, H7/h6, H7/k6 and H7/p6, with minimum and maximum clearance or interference. Nominal sizes up to 500 mm.

Tap Drill and Clearance Hole Chart

Tap drill sizes and clearance holes for metric coarse threads M2 to M24 (ISO 273 medium fit) and common UNC threads, for machinists and designers.

Cutting Speed and Feed Calculator

Calculate spindle speed (RPM), table feed rate and material removal rate for CNC milling from cutting speed, tool diameter, chip load and number of flutes.

Anodizing Dimension Change Calculator

Estimate how much anodizing changes part dimensions: growth per surface, outside diameter, bore and thread allowance for Type II and Type III (hard) anodizing.