Klein Tools KTSB15 Step Drill Bit #15 Double Fluted 7/8 to 1-3/8-Inch with Easy-to-Read Step Markings and Targets, 3/8-Inch Hex Shank

This step drill bit is outstanding — fast, sharp, and built to last. It cuts through metal like a hot knife through butter, even at low drill speeds, making it perfect for clean, precise hole expansion in stainless steel, sheet metal, and other tough materials. Many reviewers mentioned how surprised they were at how quickly it cuts, even on the first try. Performance: The bit delivers smooth, fast cuts with minimal effort. It’s especially effective on stainless steel when paired with proper cutting fluid or cooling techniques. The stepped design provides excellent control, allowing you to stop at the exact size you need without over-cutting. Even after dozens of holes, it stays sharp and efficient. Build Quality: This is a professional-grade bit — sturdy, well-machined, and extremely durable. Users have reported drilling over 100 holes with no noticeable dulling. It’s a tool worth the investment, especially compared to cheaper brands that chip or wear out quickly. Ease of Use: The bit works best at low speed to prevent overheating or chipping. A little lubricant or water cooling makes a big difference. It’s ideal for projects like sink installations, drain pans, electrical boxes, and sheet metal work. Sharp, smooth cutting through tough materials Ideal for stainless steel, sheet metal, and PVC Durable and stays sharp after many uses Precise step sizing for clean, accurate holes Works best with low speed and cutting fluid Professional-grade quality worth the price This step drill bit isn’t just another tool — it’s one of those buy-it-once, use-it-forever kind of products. Perfect for pros and DIYers alike who want precision and long-lasting performance.

high quality tool for drilling hole in steel sink to install DIY under sink water filter.

I’ve never seen a step bit expand a hole so fast, even on the lowest speed setting. This is a very serious tool and worth the money. For those that don’t have much experience, never use this on anything higher than the lowest speed setting on your drill, even at mid speed, you can easily chip the blades and need to buy a new one. I chipped a blade on my second hole but that was user error, I’ve since learned and drilled another 150+ no problem.

Here is what I did. Needed to make a extra hole for my sink sprayer, since the original is being used for a filtered water spicket. With a marker I put a dot exactly where I needed the hole, had some extra caulking in the garage so I made a circle around the spot too hold a little bit of motor oil in the spot needed, make the circle bigger around. Set drill on high speed and once the pilot tip goes through, give it short 2 second bursts until you get your size hole. Making the hole took maybe 30 seconds, prep work took less than 10 minutes. This bit cut through it like butter. Superb design and quality.

I used this drill bit today to open up existing holes in the sheet metal frame of my vehicle for a trailer hitch install. The description says 3/8" hex shank but mine was 5/16" hex. I needed to snake it up through the exhaust system. So, I just put a 1/4" drive tool on my cordless drill with a short extension and then a 5/16" six point, 1/4" drive socket. The bit cut through the (likely) hardened sheet metal like butter. Chips fly everywhere so you need to wear goggles or a mask. Glasses won't cut it. The faster you spin it, the smoother it runs. At the end, I ran it in reverse to clean up the edge. Wiped the bare edge with some gun bluing for protection. One improvement would be to label the hole diameters for the steps. I assume Klein figures electrician customers just need those hole sizes indicated. I stopped short of the 1-1/8" as the hole was big enough to pass the carriage bolt through. All-in-all, great purchase. I preferred the name brand over Chinese label.

We use this step bit and the beauty forty to create another hole for a faucet in a new sink.We purchased that only had one. It worked great!

The is by far the best drill bit I have ever used. I needed to drill a hole in a stainless steel sink. I was installing a filtered water faucet. I had heard there were hardening issues when drilling stainless steel so I was nervous doing it. I watched a few you tube videos and most showed using a step drill bit. After reading the reviews on the Klein Tools KTSB14 Step Drill Bit I decided to purchase one. To keep the stainless steel cool, I placed ice cubes around the spot where I was going to drill the hole. I dipped the Klein Tools KTSB14 Step Drill Bit in a small bowl of water with ice cubes to keep it cool. Drilling at a very SLOW speed and applying a lot of pressure I started to drill the hole. At first it only made a dimple. I again dipped the bit into the iced water and then started drilling again but at a LITTLE faster speed. Once the bit started cutting there was no stopping. It cut like a hot knife in butter. I dipped the bit into the iced water for a third time and started drilling some more. In seconds I was done. The hole was perfectly cut thanks to the markings on the side of the bit and the bit was cold to the touch thanks to the iced water and slow speed I drilled at. It took longer to write this review than it did drilling the hole.

I bought a drain pan from Killarney Metals that was stainless steel to replace a damaged plastic drain pan and poor workmanship of the existing drain pipe. I used Klein annular cutters with Tap Magic cutting fluid to cut the initial hole. Then I used the Klein step drill bit to expand the hole to the right size for the PVC fitting. With stainless steel, it’s important not to heat the metal for it gets really hard to cut. Once I saw smoke, I would back off and use more cutting fluid. I use step drill bits to expand metal holes rather than do the entire hole to save on wear. The nice thing about the Klein is that the steps are small enough to get a nice fit. They are also some what expensive, so if it’s a one time job, you may be better served with a cheaper brand.

Excelente herramienta segunda ocasión que la compro quedé convencido

This step drill is the best tool I have found to very quickly yet reliably create the 3 standard hole sizes required to connect small diameter conduit to a steel electrical equipment box. It cuts a hole through steel plate much faster than a hole saw, and creates a perfect hole leaving no burrs. This step drill is evidently of high quality consistent with its cost, and I expect it will continue to perform well for many more jobs than similar less expensive products being sold.

Qualidade e Benefícios Klein!!

muy buena

Ótimo custo e benefício, indico!