McMaster 2070A207 Starrett Feeler Gauge Set, with NIST Certificate, 301 Stainless Steel, 31 Leaves, Model 66BS

To ensure accurate readings, these sets come with a certificate of calibration traceable to NIST that states they've passed a test for accuracy. They are used to check gaps, alignment, and narrow slots. Gauge leaves are riveted together in a fan design that folds up for portability. Each leaf is marked with thickness. Leaf-securing locks hold individual gauge leaves in place.

301 Stainless Steel — Stainless steel gauge sets are less likely to rust than tool steel gauge sets.