For checking, identifying and specifying
the roughness by symbol
Accuracy: +20% ~ -25%, Ra<0.1µm
Accuracy: +12% ~ -17%, Ra>0.1µm
Meets ISO 2632 (ISR-CS329 meets ISO 8503/1)
Rust-proof, made of pure Nickel
Roughness (Ra) :0.4, 0.8, 1.6, 3.2, 6.3, 12.5, 25, 50µm
