INSIZE 4166-3D Steel Pin Gauge Set 3.00–3.50 mm

This INSIZE 4166-3D set holds 51 steel pin gauges running from 3.00 mm to 3.50 mm in 0.01 mm steps. Meeting DIN 2269, grade 1 with ±1 µm diameter accuracy, the pins are alloy steel and hardened to HRC62-65, per INSIZE's specification. At 50 mm long per pin, the set is packed in a lined wooden storage case. A set like this is used to check drilled or bored hole sizes: the pins are tried in turn until the right fit is found, giving a direct reading of the hole's diameter.