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. 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.

Just so we are clear, I am reviewing the "DEWALT Drill Bit Set, Pilot Point, Cobalt, 29-Piece (DWA1269)" Suitable for portable or stationary drilling of high alloy content steels and metals with a tensile strength up to 1100N/mm² There aren’t many materials strong enough to put holes in hardened steel. For that kind of strength, the only answer is cobalt alloy drill bits.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. 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. 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 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.

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.

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. 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 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. Other than this, kinda tough to make any other meaningful side-by-side comparisons coz all bits are of progressive sizes.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. M42 (8% Co) + Made in the US? Easy. But you might need a drill press or the smaller bits might snap. They retail for about USD250 and upwards for a 29-piece set.