
272 Green Composites from Natural Resources
been used, which effectively serve the purpose. For conventional polymer compos-
ites using glass and carbon as reinforcements, drill bits of different materials such as
HSS, carbide drills, and high-speed steel–cobalt (HSS-Co) have been attempted to
produce a large number of damage-free holes. During drilling of resin-less bamboo
GCs with a wood drill (carbon steel) and metal drill (HSS tools), it has been found
that the wood drill is inadequate to drill GC because of the larger thrust force (about
four times larger) and poor hole quality as compared to the metal drill (Mizobuchi
et al. 2008). The effect ...