Core Drill Chuck Kit (Including 5 Copper Cores)

Optional hole diameter: 2mm, 2.3mm, 3.17mm.
Drill chuck size: 9 * 30MM
Product material: all copper (inner copper core has been electroplated into silver)
Copper core specification: with 5 cores, the parameters are as follows
6 * 18mm drill clamp copper core 3.2 (can clamp 3.2-2.5)
6 * 18mm drill clamp copper core 2.5 (can clamp 2.5-1.8)
6 * 18mm drill clamp copper core 1.8 (can clamp 1.9-1.3)
6 * 18mm drill clamp copper core 1.2 (can clamp 1.3-0.7)
6 * 18mm drill clamp copper core 0.8 (can clamp 0.9-0.3)