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

Product Information

Suitable for portable or stationary drilling of high alloy content steels and metals with a tensile strength up to 1100N/mm² The Milwaukee cobalt drill bit set exceeded our expectations in the stainless steel drilling test. While most of the other bits did a pretty good job, the Milwaukee bits bit into the stainless steel noticeably faster. The slightly elevated point, which is shorter and narrower than DeWalt’s, seemed to find a sweet spot that then allowed the rest of the cutting edge to follow. The raised center point didn’t get in the way when we sharpened the edges of the bit point, but sharpening the center of the point was more challenging. However, we found that these durable bits, housed within their well-built hard plastic case, would make a great addition to a workshop. 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. 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?

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.Counterbore. Counterbore drill bits create holes that allow the head of a fastener to sit below the material’s surface. Unlike countersink bits, which create an angled hole for fasteners with angled heads, counterbore drill bits create a larger hole at a shallower depth. A counterbored hole creates a flat ridge on which the head of the fastener can rest. When attempting to drill through a hard, smooth surface, having the right tip is crucial. Most cobalt drill bits have tips with stepped and split points that bite into the metal, which prevent the bit from sliding along the smooth surface. Shank Since the manufacturer recommends these bits for cordless drilling, we tested the Milwaukee step bits twice, first in the drill press and then in a handheld cordless drill. They drilled fast and clean as billed. Then we tested the step bit’s unique ability to enlarge existing holes—a task that is nearly impossible to do cleanly with conventional twist bits. We clamped an old steel electrical junction box to the workbench and used the #9 step bit in a cordless drill to widen the punch-out holes from ½ inch to ⅞ inch. The resulting hole was perfectly shaped, clean, and smooth, with no burs. Other than this, kinda tough to make any other meaningful side-by-side comparisons coz all bits are of progressive sizes. The Stroton cobalt drill bits featured a round shank with a low-profile stepped split point. They performed smoothly with or without center-punch starter guides. Unlike the more exaggerated pilot-style stepped points found on the DeWalt and Milwaukee bits that we tested, this design only stepped up a total of about 0.5 millimeters above the shoulders of the bit point, despite having more steps.

Whether drilling wood, masonry, acrylic, metal or any number of other materials, having the drill bit for the job will give you the ability to drill with confidence and accuracy. Some drill bit sets will offer a mix of bit type to cover all types of jobs from wood and metal through to masonry, with some also including more specific bit types such as flat wood drill bit or countersinks. Drill Bit Sets are used by professional electricians, builders, plumbers, roof installers, etc. and DIY enthusiasts. The Irwin M35 drill bits performed well before and after sharpening—in fact, the bit had barely dulled after the first three holes. With or without a center punch to premark the hole locations, these bits drilled smooth, clean holes. Also, the split point was easy to line up at the proper angle to sharpen on the grinder. You don't have permission to access "http://www.homedepot.com/p/DEWALT-Cobalt-Alloy-Steel-Drill-Bit-Set-29-Piece-DD4069/203321667" on this server.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. The Bosch cobalt drill bits offer a unique combination of structural features and extra-hard M42 alloy that make them a pleasure to work with. To test this product, we used a cordless drill and a drill press to highlight the difference between precision drill press work and handheld drilling. The cordless drill mostly worked well, but its variable-speed trigger made it more difficult to maintain a slow, precise speed for drilling steel. 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

Don’t throw away dull drill bits. Instead, sharpen them with a grinder to restore their sharp edges. Tool Steel with Tungsten Carbide Tips– TCT provides a longer working life for the bit while allowing for a more stable and solid tip and enabling it to withstand more rigorous drilling applications. Titanium drill bits are durable and will hold up much longer than standard high-speed steel drill bits, but they are not as strong as cobalt alloy, which will drill through hard metals, including titanium. Q. What are the hardest drill bits? 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.Working with the Drill America M42 drill bit was almost an identical experience to working with the Irwin drill bit set, but this set is made of tougher metal and provides easier access to all of the bits at once. Both sets offer the same size assortment, the same round shank, and 135-degree split-point construction. Drill America’s bits remained noticeably sharper after the first three test holes, so we drilled a second set of three holes before sharpening. Sharpening took slightly longer, but the split point made it easy to align them with the grinder. 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. Bob Vila has been America’s Handyman since 1979. As the host of beloved and groundbreaking TV series including “This Old House” and “Bob Vila’s Home Again,” he popularized and became synonymous with “do-it-yourself” home improvement.

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. After drilling the first round of test holes (or after the second round for some harder drill bits), we sharpened the ⅜-inch bits with a bench grinder. We held the cutting edge to the wheel for 5 seconds on each cutting edge, once on the coarse grinding wheel and once on the fine wheel, making sure to maintain the 135-degree original tip angle. To evaluate how well the bits responded to resharpening, we drilled another round of three test holes for each bit in the scrap steel. The cobalt drill bits are supplied in a large tough case, ensure secure tool storage and durability and protection in various environments

The MIC bits can scratch the MIG bits but hardness does not mean quality. The MIG bits feel sharper and seem more well-designed and well-finished. Step drill bits offer the advantage of fast, clean precision drilling into thin metals without changing bits. Each of this set of three cobalt step drill bits is designed and engineered to drill up to 1,000 holes into 14-gauge steel. They feature a rapid strike tip for faster starting, elongated dual flutes to reduce heat buildup, and smaller step gradients for smoother drilling. The Amoolo cobalt drill bits performed as well as some of the top name brands in our tests but cost a fraction of the price. They drilled smooth, clean holes, and the 135-degree split point was easy to align with the bench grinder for sharpening. It bears mentioning, however, that the kit only includes smaller bit sizes in 1/16-inch increments, which makes it ideal for crafting and detailed drilling. 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. Twist– The most common type of drill bit and ideal for drilling wood, plastic, and metals. They are generally made from HSS and are suited to general household DIY tasks, as well as professional applications like maintenance and engineering.