Sandvik Coromant Machining carbon fibre materials - Manual (Page 31)

Machining strategies
Top and bottom surface are often different, hole quality •
can therefore depend on where the drill enters or exits.
A coating or surface layer on the carbon fibre can •
change the output completely.
For example:
- Lightning Strike Protection (LSP): a fine or coarse copper mesh, allows for
higher feed rate
- Glass-cloth coating: increases the risk of delamination
- Both materials can be more easily machined by chosing the correct geometry.
CoroDrill 854 CoroDrill 856
Delamination
Lightning Strike Protection (LSP) layer on
CFRP material CFRP with glass-cloth coating
Solution
Splintering/ fraying
Hole quality issue
CoroDrill 854: Point geometry designed to prevent
splintering and fraying.
CoroDrill 856: Designed to reduce delamination
problems.
SANDVIK COROMANT USER’S GUIDE - COMPOSITE SOLUTIONS 31