How do I describe my part so it’s right first time?

The more detail you give, the fewer questions you’ll get back. State in millimetres:

• the outer shape and dimensions, for example ‘rectangle 200 × 100 mm’;
• the thickness, for example ‘3 mm’;
• each hole: diameter and position, for example ‘hole Ø9, 15 mm from the edge’;
• for holes in a circle: number, diameter and pitch circle diameter;
• for a bent part: where the bend is, the angle and the length of each flange.

Example: ‘Make a flange ring 160 mm in diameter, 5 mm thick, with a centred 70 mm bore and 8 bolt holes of 9 mm on a 125 mm pitch circle.’