Our Center Drill Bit Set features a wide range of sizes, high-speed and solid construction, and 60-degree angle for accurate center holes. Made of premium quality high-speed steel, this set can be used with lathe machines and electronic drills to work with tough materials. Tips are also included for best use.<br> <br> Features:<br> <br> 1. Wide Range of Sizes Optional: Cutting Diameter x Length: 1 x 33mm, 1.5 x 33mm, 2 x 40mm, 2.5 x 44mm, 3 x 70mm, 4 x 70mm, 5 x 70mm optional, to meet different needs.<br> 2. Accurate: The 60-degree angle center drill is very useful in drilling accurate center holes, 60-degree countersink holes, or starter holes for bigger drill bits in metal-working.<br> 3. Premium Quality: Our center drill bits are made of high-speed steel, solid and high-temperature, and wear-resistant.<br> 4. Widely Applicable: Can work with lathe machines and most electronic drills to drill holes in Steel, Iron, Alum, Carbon Steel, Brass, and other tough material ranging from 170HB up to 200HB.<br> 5. Tips For Using Center Drill Bits:<br> Fix the work piece deep in the Lathe machine to prevent wobbling when rotate.<br> Get rid of the acid surface before drilling and use oil or proper lubricant to protect the bits.<br> A good rule to follow is to go 2/3 deep on the tapered section.<br> Stop immediately if the drilling sound is abnormal and fix any problem before resuming.<br> Clean the center drill bits before and after drilling, and apply oil to store it properly.<br> <br> Specification:<br> Material: High Speed Steel<br> Color: Silver <br> Product Size: Cutting Diameter x Length: 1 x 33mm, 1.5 x 33mm, 2 x 40mm, 2.5 x 44mm, 3 x 70mm, 4 x 70mm, 5 x 70mm <br> Product Weight: 2g, 3g, 5g, 7g, 12g, 19g, 30g<br> <br> Package Included:<br> 1 x Center Drill Bit