Inch.
Used to produce a close tolerance surface finish by hand in almost any environment i.e. on site or in a workshop. Manufactured to BS 328-4 and DIN 206B.

INCH TOLERANCES:
Diameter: ~ up to 0.1181. Tolerance: +0.0005, -0.0013.
Diameter: Over 0.1181 ~ up to 0.2362. Tolerance: +0.0004, -0.0002.
Diameter: Over 0.2362 ~ up to 0.3937. Tolerance: +0.0005, -0.0002.
Diameter: Over 0.3937 ~ up to 0.7087. Tolerance: +0.0006, -0.0003.
Diameter: Over 0.7087 ~ up to 1.1811. Tolerance: +0.0007, -0.0004.
Diameter: Over 1.1811 ~ up to 1.9685. Tolerance: +0.0008, -0.0004.
Diameter: Over 1.9685 ~ up to 3.1496. Tolerance: +0.0010, -0.0005.