DEWALT Cobalt Alloy Steel Drill Bit Set with Pilot Point, 14-Piece (DWA1240)

Product Information

The kit includes #1, #4, and #9 step bits. The #1 bit drills from ⅛-inch to ½-inch holes, with step increments of 1/32 inch. The #4 bit makes holes 3/16 inch to ⅞ inch, in 1/16-inch increments. The #9 bit drills ⅞- to 1⅛-inch holes in 1/16-inch increments. Read on to find out more about our shopping considerations and testing process. This guide will help you find the best cobalt drill bits for turning metal into Swiss cheese. In addition, be aware that drilling into hard metal requires a special technique to ensure that the bit cuts into the metal smoothly without overheating. Use a quality drilling lubricant with a high flash point. We used 3-In-One Multi-Purpose Oil for our tests. Also, drill at a slower speed with moderate downward pressure to avoid damaging expensive bits. The smallest bits can safely drill at about 3,000 rotations per minute (rpm), but larger bits should turn no faster than about 1,000 rpm. How We Tested Cobalt Drill Bits thing, these are manufactured in GERMANY, not China. They have a nice heavy feel to them. Also appear to have a nice coat of oil on the bits.

These work well. I bought them to drill approximately 1/8" (.125") stainless steel and they drilled through it with easy. I used a hand drill at low speed and sprayed it with WD40 (not the best cutting fluid) a couple of times. DWA1269 - First, there's nothing wrong with the the metal case. Nothing special but nothing wrong. Next, in this era, this is a steal if you can buy this 29-piece M35 set for about USD120 or less. The cobalt drill bits are supplied in a large tough case, ensure secure tool storage and durability and protection in various environments Not easy to find non-MIC M35 (5% Co) sets here unless you want things cheap. In fact, this might be the only set as of now.Because the step bit’s cutting edges run from top to bottom along the edges of the flutes, instead of at the tip only like twist bits, we approached resharpening differently. We clamped the bit in a vice and used an angle grinder to touch up the cutting edges. It worked fine, but we had to be extra cautious not to damage the size markings. Drilling through steel, cast iron, and other metals produces tiny shards that can end up in skin or eyes, so make sure to wear protective gloves and safety glasses when working with cobalt drill bits. For the first round of drilling evaluations, we selected the 1/16-inch, 3/16-inch, and ⅜-inch bits from each set. The test materials included scraps of .25 sheet aluminum, .133 cast-iron pipe, and .065 square tubular stainless steel. We calibrated the drill press rpm to match the bit size and material based on this chart and used 3-In-One Multi-Purpose Oil as a drilling lubricant. We drilled three holes in each of the test materials with every drill bit and then noted penetration speed (aggressiveness), cleanliness of the hole edges, and any noticeable changes from the first to the last hole. There are four types of cobalt drill bits, with each type serving a specific purpose. Understanding the right application for each bit type is essential. Cobalt drill bits consist of steel with a small percentage of cobalt—the higher the percentage of cobalt, the more heat-resistant and durable the drill bits will be. The amount of cobalt in a drill bit varies. An M35-grade cobalt bit contains 5 percent cobalt, while an M42-grade cobalt bit contains 8 percent. The higher the grade, the more expensive the bit. Tip Point

While cobalt drill bits will hold up better against heat than other drill bits, they will need to be sharpened from time to time. Sharpen dull cobalt drill bits using a bench grinder. Q. Are cobalt or titanium drill bits better? Countersink. Countersink drill bits create shallow holes that allow the head of a fastener to sit flush with the material and are angled to match the tapered head of the fastener. Cobalt countersink bits will create countersink holes in hard metals. Unlike twist drill bits, which include self-piloting tips, countersink bits require an existing hole to drill into a material. To drill countersink holes, twist bits are needed to drill the initial hole, then countersink drill bits are used to create the countersink holes. Only use cobalt bits for drilling holes in metal, as the bits are too powerful for wood and other materials. HSS (High-Speed Steel)– HSS can withstand higher temperatures without compromising the hardness of the bit and is able to cut faster with more accuracy and efficiency.It takes a tough bit to drill through hard metals like steel and bronze, but drill bits like these from Stroton are up to the task. Stroton uses what it calls a three-step design with this drill bit. Borrowing from step-bit technology, the tip of the bit is composed of three separate steps that help drive the bit through hard metals. This 19-piece metric set features sizes ranging from 1 millimeter to 10 millimeters. Drill bits are cutting tools that are used to remove material in a piece to create a circular hole. Having the right size and the right type of bit is key in ensuring the highest standard of work and ensuring that you can drill with confidence and accuracy. Learn more in our drill bit sets guide. bits and smaller do not have the 3 flats, nor "Made in Germany" stamp (too small most likely), but do say "HSS-CO" on them where the larger bits do not specify the metal grade.