In mechanical drawing, mm is generally the default value. what do you think?

1.op command calls up "Options". First, confirm whether it is a metric unit.

2. reconfirm the unit:

In addition: what is the drawing scale?

Generally speaking, the scale in a drawing frame in cad is to select an appropriate numerical scale and place the whole figure in the required drawing frame.

This is related to the selected drawings (A0, A 1, A2, A3, A4). The principle is that after the drawings are printed, they can show clear graphics.

What is the practical application of proportion? In drawing paper's era, according to the scale marked in the drawings, the dimensions in the actual surveying and mapping drawings were multiplied by the scale (such as 1:2 multiplied by 2), and the dimensions of the parts could be obtained.