Project Farm tests several products to find the best cutting oil for drilling through both mild and hardened steel, including:
- Tap Magic Cutting Fluid,
- CRC C3400 Truetap Cutting Fluid,
- Rapid Tap Cutting Fluid,
- CLI Syntec Premium Metal Tapping Fluid,
- Lenox,
- 3-in-1 Oil,
- used motor oil,
- bacon grease, and
- shortening.
Brand new twist drill bits were used for each product tested. In a recent video on twist drill bits, DeWalt and Bosch did well but using a high quality cutting oil helps a lot.
