Description: Collet Chuck Milling Tool Holder with Spring Collets Set.    Specification: Collet Chuck: Material:Metal;  Size:121cm;  Spindle: Drawbar thread:7/16;  Clamping range:1-20mm;  Spanner:250mm.    Spring Collet Set: Material:high grade spring steel;  Color:steel color;  Length:39mm;  Diameter:32mm;  Inner diameter:2mm-20mm;  Quantity:19pcs.    Features: -Available in the BT ER extension rod handle, can be used for clamping drill, milling cutter, straight shank tool.  -Collet must be assembled into the clamping nut before inserting into the chuck.  -Performance stability, high accuracy.  -Ease of operation and high quality work results.    Note: 1. Before using this tool, please measurement tool deflection, tool deflection accuracy exceeds 0.01MM, please correct before cutting.  2. The tool extends the length of the chuck as short as possible, the tool extends the amount of time longer if extended, please cut their own speed, feed rate or cutting the amount.  3. If the cutting of abnormal vibration or sound, cut spindle speed and depth of cut to improve the situation so far.    Package Included: 1 x Collet Chuck;  1 x Spanner;  19 x Spring Collet Set;  1x Storage box