More info
This specification, CHINA TRY SQUARE RULER - L/DUTY 0.8mm, M/DUTY 0.9mm, is likely referring to the thickness of the blade on different versions of a Try Square ruler
Here is a breakdown of what each part most likely means:
Try Square Ruler: A common woodworking and metalworking tool used to mark and check 90-degree angles (squareness).
CHINA: Indicates the country of origin for the manufacturing.
L/DUTY (Light Duty): This version is intended for lighter, less demanding use.
0.8mm: Refers to the thickness of the metal blade (the ruler part). A thinner blade is less expensive to produce and suitable for casual use.
M/DUTY (Medium Duty): This version is designed to be more robust for more frequent or demanding work.
0.9mm: Refers to the thickness of the metal blade. A slightly thicker blade offers more rigidity, durability, and resistance to bending, making it a better quality or more durable tool.