Due to oxidation, a little rust may appear. This will not affect normal use.
Tips:
1.Appropriate addition of coolant (e.g., water) can extend the service life when tapping.
2. The force must be uniform in tapping operations.
3. First drill the hole with twist drill, and then use the taps tapping. Tapping angle should be vertical 90 degree and keep stable.
4. Tapping depth should not exceed 1.5 times the diameter of the tap: For example: diameter of M6x1 about 6mm, the depth should not exceed 9mm.