Excellent hole quality is necessary for the aerospace industry’s highly abrasive carbon fiber reinforced polymer (CFRP) drilling process. This work considered three different twist drill designs, tapered web, burnishing, and subland drill reamer for the drilling process. The drill bits were made of tungsten carbide and machined with custom helix angle, primary clearance, point angle, and chisel angle. The primary objective of this research is to determine the thrust force signature for each custom drill bit design and the delamination factor for the hole drilling at 3000 rev/min and 0.05 mm/rev. The finding indicates that the tapered web gave the best design by improving the maximum thrust force by 14.6% in drilling CFRP panels. Additionally, the tapered web design led to a low delamination factor on both entrance (1.0186) and exit sides (1.0475). The thrust force is directly proportional to the delamination factor when drilling a CFRP material in a single shot operation. The subland drill reamer produces higher thrust force, and delamination proved that the combination of drill and reamer design was unsuitable for high-speed drilling.

• An, Q. L., Xu, J. Y., Cai, X. J., & Chen, M. (2013). Experimental investigation on drilling force and hole quality when drilling of T800S/250F CFRP laminate. Advanced Material Research, 797, 155-160. https://doi.org/10.4028/www.scientific.net/amr.797.155

• An, Q., Cai, X., Xu, J., & Chen, M. (2014) Experimental investigation on drilling of high strength T800s/250f CFRP with twist and dagger drill bits. International. Journal of Abrasive Technology, 16(3), 183-196.

• Ashrafi, S. A., Sharif, S., Farid, A. A., & Yahya, M. Y. (2013). Performance evaluation of carbide tools in drilling CFRP-Al stacks. Journal of Composite Materials, 48(17), 2071-2084. https://doi.org/10.1177%2F0021998313494429

• Feito, N., Muñoz-Sánchez, A., Díaz-Álvarez, A., & Miguelez, M. H. (2019). Multi-objective optimization analysis of cutting parameters when drilling composite materials with special geometry drills. Composite Structures, 225, Article 111187. https://doi.org/10.1016/j.compstruct.2019.111187

• Higuchi, R., Warabi, S., Ishibashi, W., & Okabe, T. (2020) Experimental and numerical investigations on push-out delamination in drilling of composite laminates. Composites Science and Technology, 198, Article 108238. https://doi.org/10.1016/j.compscitech.2020.108238

• Hou, G., Zhang, K., Fan, X., Luo, B., Cheng, H., Yan, X., & Li, Y. (2020) Analysis of exit-ply temperature characteristics and their effects on occurrence of exit-ply damages during UD CFRP drilling. Composite Structures, 231, Article 111456. https://doi.org/10.1016/j.compstruct.2019.111456

• Jaafar, M. F., Salleh, M. S., Izamshah, R., Hassan, M. H., Sundi, S. A., Hafiz, M. S. A., & Kasim, M. S. (2019) Influence on thrust force and delamination for one shot drilling of carbon fibre reinforced plastic (CFRP). International Journal of Mechanical & Mechatronics Engineering, 19(1), 43-56.

• Jia, Z. Y., Zhang, C., Wang, F. J., Fu, R., & Chen, C. (2020) An investigation of the effects of step drill geometry on drilling induced delamination and burr of Ti/CFRP stacks. Composite Structures, 235(1), Article 111786. https://doi.org/10.1016/j.compstruct.2019.111786

• John, K. M., Kumaran, S. T., Kurniawan, R., & Ahmed, F. (2021) Evaluation of thrust force and delamination in drilling of CFRP by using active spring restoring backup force. Materials Today: Proceedings, 49, 269-274. https://doi.org/10.1016/j.matpr.2021.02.033

• Katiyar, P. K., Singh, P. K., Singh, R., & Kumar, A. L. (2016) Modes of failure of cemented tungsten carbide tool bits (WC/Co): A study of wear parts. Journal of Refractory Metals and Hard Materials, 54, 27-38. https://doi.org/10.1016/j.ijrmhm.2015.06.018

• Liu, L., Qi, C., Wu, F., Zhang, X., & Zhu, X. (2018) Analysis of thrust force and delamination in drilling GFRP composites with candle stick drills. The International Journal of Advanced Manufacturing Technology, 95(5), 2585-2600. https://doi.org/10.1007/s00170-017-1369-8

• Senthilkumar, M., Prabukarthi, A., & Krishnaraj, V. (2013). Study on tool wear and chip formation during drilling carbon fiber reinforced polymer (CFRP)/titanium alloy (Ti6AL4V) stacks. Procedia Engineering, 64, 582-592. https://doi.org/10.1016/j.proeng.2013.09.133

• Wika, K. K., Sharman, A. R. C., Goulbourne, D., & Ridgway, K. (2011). Impact of number of flutes and helix angle on tool performance and hole quality in drilling composite/titanium stacks (No. 2011-01-2744). SAE Technical Paper.

• Yang, Y., Yang, Y., Liu, X., Huang, K., & Ren, H. (2019) Optimized design and application of a directional reaming-while-drilling polycrystalline diamond compact bit. Engineering Failure Analysis, 105, 699-707. https://doi.org/10.1016/j.engfailanal.2019.07.023