Made in Japan, this high precision square is accurate, reliable and well made.
External Dimensions 200 x 130 x 22 mm
Accurate to better than 22 microns (0.87 thou)
Angle tolerance +/- (20 + ℓ / 10) μm where ℓ is the nominal length (mm)
Annealed tool steel for maximum dimensional stability (not corrosion resistant)
Manufactured in accordance with Japanese Industrial Standards (JIS) B7526 Grade 2
Precision ground measurement surface
Please note: Unlike BS939 the Japanese engineering standard B7526 doesn't call for a burr groove at the internal corner.