SYOSI Center Drill Bit Set - HSS 7 Pieces 1.0 1.5 2.0 2.5 3.0 4.0 5.0mm

Specification: Name: Center Drill Bit Set Material: High Speed Steel ( HSS ) Size: 1.0 1.5 2.0 2.5 3.0 4.0 5.0 (mm) Quantity: 7 Pieces How to use center drill bits? 1. Fix the work piece deep in the Lathe machine to prevent wobbling when rotate 2. Get rid of acid surface before drilling and use oil or proper lubricant to protect the bits 3. A good rule to follow is to go 2/3 deep on the tapered section 4. Stop immediately if the drilling sound is abnormal and fix any problem before resuming 5. Clean the center drill bits before and after drilling, and apply oil to store it properly. 6. stored in a solid storage case. Number 1 and Number 4 are the two most common sizes.