Technical Drawing Standards: Centring Marks
The BS ISO standards require ‘Centring’ marks on Engineering Drawings.
If you are producing ‘Shop’ drawings in the construction industry you may chose to use an Engineering or an Architectural style drawing frame. This a matter for your company standards.
Centring marks help to align the drawing when it’s being copied or microfilmed. If you want to include centring marks in your drawing frame, they should be 10mm wide and placed at the centre of each edge of your drawing frame. They don’t have to be a single line, the design of the centring marks is up to you (go wild!)