Investigation of Drilling Parameters Using Grey Relational Analysis and Response Surface Methodology of Biaxial Glass Fibre Reinforced with Modified Epoxy Resin Composite

Table 2

Different control parameters and their levels.

Control parameter	Unit	Level 1	Level 2	Level 3
Thickness	mm	2	—	3
Drill bit	—	1	2	3
Feed	mm/min	0.05	0.1	0.15
Speed	rpm	800	1000	1200