Machining charts & reference library
Find a dimension, understand a thread callout or check a machining formula. These original guides explain the calculation and point to the relevant manufacturer or standards source when a controlled table is required.
Fractional drill sizes: inches to millimetres
Convert common fractional drill diameters to decimal inches and millimetres, and understand where number and letter drills fit.
Tap drill selection: cutting and forming taps
Choose tap drill information by thread size, pitch, tap type and material. Calculate an estimate, then confirm the hole specification.
Pipe thread drilling and taper reference
Understand why pipe thread drill sizes, taper and gauging need a thread-specific manufacturer or standards reference.
Wire thread inserts: drill and tap preparation
Plan the drill, STI tap and inspection steps for wire-insert repairs without confusing the receiving thread with the finished screw thread.
Socket heads and countersunk screws: machining reference
Match clearance, counterbore and countersink preparation to the selected fastener, with tools for 82° and 90° conical geometry.
GD&T position and dimensional inspection
Understand the difference between a coordinate position calculation and complete drawing-based GD&T inspection.
G-code and M-code: CNC programming reference
A compact starting reference for common milling motion, feed and machine functions, with links to the control manufacturer’s manual.
From a reference to a calculation
Use the machinist toolbox to calculate speeds, feeds, angles and nominal hole centres. A standard, drawing or tool maker’s data determines the input requirements; the calculator makes the arithmetic visible.