Machining method: cylindrical lapping.
Ra: 1, 2, 4, 8_in. Rz: 18, 22, 25, 49_in. Quantity 4pcs; superfinishing. Ra: 1, 2, 4, 8_in. Rz: 14, 28, 40, 56_in. Quantity 4pcs.
For checking, identifying and specifying the roughness by symbol.
Rust-proof, made of pure Nickel.

3M 65491, Pro Grade Precision Ultra Durable Universal Hole Sanding Disc, DUH5220TRI-10T, 5 IN x UH, 220, 7100202880, 10 per pack
Insize 0120-IM24, INDUCTIVE MOISTURE METER, 0~100%, 6974029776588
3M 54135, Scotch-Brite Roloc AL Surface Conditioning Disc TR, 2 in x NH A VFN, 7100075708, 200 per case 