INSIZE 4166-6 Steel Pin Gauge Set 5.50–6.00 mm

The INSIZE 4166-6 is a steel pin gauge set covering 5.50–6.00 mm across 51 pins, stepped every 0.01 mm. INSIZE states the pins meet DIN 2269, grade 1 with ±1 µm diameter accuracy, machined from alloy steel and hardened to HRC62-65. Each pin is 50 mm long and the set is supplied in a lined wooden case. Pin gauge sets like this let a workshop check a hole or bore diameter directly: a technician works through the pins until finding the one that fits, reading off the size marked on its handle.