Supporting your need to build large robots (at a smaller scale).
Set of 10 tungsten steel drill bits. Includes 0.3-1.2mm sizes.
The chip removal space of the drill is large, which in return makes the chip removal resistance low. The drill has strong cutting force which can improve the hole-wall quality effectively.
See also: DSPIAE AT-HD Aluminum Alloy Hand Drill (DB-03 drill bits are included in AT-HD set)