Bosch Electrician Pliers 180 mm 1600A02NE1

Collets are the tapered clamping sleeves that hold the bit in a router or die grinder. Size follows the bit's shank diameter — 6, 6.35 (1/4"), 8, 12 and 12.7 mm (1/2") are the common ones — and the collet works together with its nut: a worn nut spoils the grip of a sound collet. A collet that does not match the shank runs the bit off centre and costs surface finish. Bosch order number 1600A02NE1.