What method involves placing millimeters in brackets in United States drawings?

The bracket method is used in United States drawings to denote measurements in millimeters by enclosing them in brackets. This technique serves to clearly distinguish metric measurements from imperial measurements, which might be presented in inches. By placing the millimeter values in brackets, it prevents confusion, especially in contexts where both measurement systems are in use. This method is particularly helpful in engineering and manufacturing drawings where clarity and precision are critical for fabrication and assembly.

Using this format ensures that anyone reading the drawing can quickly identify the units being used, reducing the likelihood of errors that could arise from misunderstanding the dimensions, ultimately enhancing communication among engineers, fabricators, and welders.