Resources

An engineer's overview of CNC machining — the processes involved, the machines we use, what tolerances are achievable, and how to design parts that are straightforward to manufacture.

How to read and write ISO tolerances and fits on engineering drawings — so your parts come back right first time, without unnecessary cost.

What Ra values mean in practice, which surface treatments are available, and how to call them up correctly on your drawings.

A working guide to the metals and engineering plastics we machine most often — covering machinability, mechanical properties, and where each material performs best.

ISO metric thread sizes from M2 to M24 — pitch values, tap drill diameters, and clearance drill sizes for both coarse and fine series.

What Ra, Rz, and Rq actually measure, how they differ, and the roughness values you can expect from different machining operations.

Which file formats work best when submitting parts for CNC machining, what to include alongside your 3D model, and common mistakes to avoid.

A concise reference to the Geometric Dimensioning and Tolerancing symbols you'll encounter on precision engineering drawings.