MACXCOIP 115pcs Cobalt Drill Bit Set Review: a big, cheap set that actually bites into metal

I grabbed this MACXCOIP 115‑piece cobalt drill bit set because I was tired of hunting for the right size and burning up cheap black-oxide bits on stainless and hardened bolts. Around me, a single cobalt bit from a big brand can cost almost as much as this whole kit, so I figured I’d try the budget route and see if it was junk or actually usable. I’ve used it for about three weeks now on small garage projects and a couple of tougher jobs on the car and some steel brackets.

My use is what I’d call serious DIY: not a pro shop, but I do drill into steel, stainless hardware, and the usual wood/plastic stuff pretty often. Before this, I mainly used individual Dewalt and Bosch bits and a random mix of cheap sets from the hardware store. Those cheaper ones usually dull fast, especially on anything harder than mild steel, and the cases fall apart. So I was curious whether this full index from 1/16" to 1/2", plus letters and numbers, was going to be a throwaway or something I’d actually rely on.

First impression: it’s not perfect, but it’s far from junk. A few small bits feel a bit fragile, and this isn’t at the level of high-end industrial cobalt sets, but for home and light shop use it honestly holds up better than I expected. The 135° split point and the fact that they actually cut into hardened bolts and stainless without instantly smoking is the main thing that made me keep using them instead of going back to my old mix.

If you’re expecting pro-grade cobalt that you hammer all day in a machine shop, you’ll probably find the limits. But if you’re like me and want a complete size range that can still bite into tougher metals without spending a fortune, this set lands in that “pretty solid for the money” category. It’s not flawless, yet it definitely gets the job done for typical DIY and auto repair tasks.

On value, this set is kind of the whole point. For roughly the cost of one or two name-brand cobalt bits, you get a full 115-piece index with every size you’re likely to need. One of the Amazon reviewers nailed it: they went in needing a single bit, saw that a standalone Dewalt/Milwaukee/Bosch bit was almost the same price as this entire set, and just bought the set instead. I’m in the same boat. I was about to grab a couple of individual cobalt bits for a project, then saw this and decided to gamble on the full kit.

In practice, that gamble paid off. Even if I only seriously use 15–20 of the most common sizes, the fact that I also have all the weird letter/number bits available is handy for tapping, odd hardware, and random fixes. And if I ruin one or two bits over time, I still feel like I got my money’s worth. The performance on metal is solid enough that I don’t feel like I bought a toy, and the metal case and full index make it feel like a real tool, not a bargain-bin throwaway.

Obviously, there are better bits out there if you’re willing to pay a lot more. A high-end cobalt set from a big industrial brand will likely last longer in heavy use and be more consistent across every size. But for a regular DIY user or weekend mechanic, that price jump is hard to justify. This MACXCOIP set sits in a nice middle spot: cheap enough to not stress over, but decent enough to actually use on tough materials.

If you only ever drill into wood and drywall, this is overkill and you could buy a much cheaper basic HSS set. If you regularly drill into metal (especially stainless or hardened bolts) and want a complete size range without spending a fortune, the value here is pretty strong. It’s not perfect, but for the money, it’s honestly hard to complain.

Design-wise, the set is pretty straightforward: standard jobber-length bits with a 135° split point and a twist design that’s meant to clear chips quickly. The 135° point is noticeable in use. Compared to my older 118° bits, these walk less on metal if you apply some pressure and keep the drill steady. On flat steel, I could usually skip center punching for smaller holes, though I still recommend punching for accuracy. On rounded surfaces, like a shock bolt, I still needed to punch or start very slowly to keep it from skating.

The metal index box is one of the nicer aspects for this price range. It’s not heavy-duty industrial, but it feels way better than the cheap plastic folding cases that crack in a month. The lid closes properly, and the latch on mine hasn’t popped open in the toolbox yet. Inside, each bit has its own slot, and sizes are printed or stamped clearly. After a few uses, I was able to put bits back in their correct spots without hunting around. That sounds basic, but with 115 bits, organization matters or you just end up with a mess.

On the downside, the internal trays aren’t bulletproof. If you drop the box hard or toss it around, the smaller bits can jump out of their slots and you’ll spend a few minutes putting everything back. Also, the paint/finish inside the box shows scratches pretty fast, which doesn’t affect function but makes it look used quickly. The hinge also feels like an obvious weak point long-term; it’s fine now, but I wouldn’t stand on the box or use it as a step.

Overall, the design is practical and basic. Nothing fancy, nothing clever, just a big, organized set in a metal box. For a home workshop or garage, that’s honestly all I need. Just don’t expect the case to survive construction-site abuse forever, and treat it like a tool, not like a toolbox you can throw off a truck.

The bits are advertised as M35 cobalt high-speed steel, which usually means about 5% cobalt mixed in. That’s a common alloy for bits that need to handle tougher materials like stainless and hardened steel. I obviously didn’t lab-test the metal, but in use they behave closer to real cobalt than to basic HSS: they hold an edge longer on metal and don’t blue instantly if you don’t go crazy with speed. I drilled several 6–8 mm holes through 4–5 mm thick mild steel angle with one bit, using cutting oil, and it still felt sharp afterward.

I also tested on a case-hardened shock bolt and some stainless hardware. With regular black-oxide bits, I usually end up with smoke and a ruined tip halfway through. With these, I could feel the bit actually biting instead of just polishing the surface. I still had to go slow, keep pressure steady, and use oil, but they cut through without burning. That lines up with what a few Amazon reviewers said about drilling out broken machine screws and hardened bolts.

The finish is listed as Titanium Aluminum Nitride, which is that dark coating you see on some metal-cutting bits. In practice, the coating helps a bit with friction and wear, but it’s not magic. If you crank the drill at max speed with no lubrication into stainless, you’ll still dull the bit. After a few uses, the coating at the cutting edge starts to fade, which is normal. The shanks stay intact and don’t round off easily, even in a keyed chuck that I tend to over-tighten.

To be clear, this set is not indestructible. The smallest bits are still fragile, and if you side-load them or try to bend them while drilling, they will snap. One Amazon reviewer mentioned breaking four bits early on, and I can see how that happens if you’re rough or misaligned. For most DIY metal work, though, the material quality feels decent. It’s definitely a step up from the really cheap silver-and-demeset-type HSS sets, but not quite at the level of high-end industrial cobalt from top brands. For the price, the materials feel honest: good enough if you use them correctly.

Durability is where I was the most skeptical, especially after reading that one Amazon review where the guy broke four bits early on and only changed his mind after getting a replacement set. In my case, after a few weeks of use, I haven’t snapped any bits yet, but I’ve been careful with the smaller sizes. I used the tiny ones only for light pilot holes in metal and plastic, keeping the drill straight and avoiding side pressure. If you’re rough or use them to enlarge misaligned holes, they’ll snap like any other small bit, cobalt or not.

Edge retention has been decent. My most used sizes (around 1/8", 3/16", and 1/4") have gone through multiple holes in mild steel and a bit of stainless. They’re not as sharp as out of the box, obviously, but they still cut without squealing or polishing the surface. I haven’t had to sharpen any yet, which is good. If you’re the type to drill dry and too fast, you’ll probably end up dulling them faster and complaining they don’t last. Used with oil and moderate speed, they hold up better than my old budget sets.

The coating and shanks are also holding up. There’s some discoloration near the tips from heat, which is normal, but no blue “I cooked this bit” lines yet. The shanks aren’t rounding off in my chucks, and none of them have twisted. The case, as mentioned earlier, shows scratches and some wear inside, but nothing functionally bad. The bits stay in place if I carry the box upright; if I drop it or lay it sideways and shake it, some of the tiny bits wander out of their slots.

Long term, I’d say the set feels good enough for regular home use. If you’re a pro drilling steel all day, you’ll probably wear these out faster than a premium brand, and you might be better off buying fewer, higher-end bits in the sizes you use daily. For a home garage or hobby workshop, though, I don’t see myself replacing this set anytime soon. It’s not indestructible, but it’s far from disposable.

In terms of performance, these bits do what they claim as long as you respect basic drilling rules. On wood and plastics, they’re almost overkill. I drilled several 6–10 mm holes in pine studs and plywood, and they went through like butter with clean exits and no burning. On plastic (PVC and ABS), they also cut cleanly without grabbing too much, but I had to ease off on the trigger because the 135° point and sharp edges can pull in fast if you’re heavy-handed.

The real test for me was metal. I drilled through 1/8" and 3/16" mild steel angle, some 2 mm stainless brackets, and that case-hardened suspension bolt. With a corded drill at low speed and a bit of cutting oil, they cut consistently. Chips came out in nice spirals, and the bit didn’t chatter much. The self-centering point helps reduce walking, but for precise holes I still used a center punch. Compared to my old generic HSS bits, I noticed two main differences: less heat build-up and the edge stayed usable after multiple holes instead of dying halfway.

On really hard stuff, you still need patience. When I worked on the shock bolt, I stepped up bit sizes slowly, similar to what one Amazon reviewer described. Starting with a small pilot, then going up in small increments, one of the mid-size bits finally bit into the broken bolt and helped back it out. That job alone would have destroyed my cheap bits, but this set handled it fine. I wouldn’t say it was effortless, but it got the job done without me having to pull the whole assembly apart.

Overall, performance is pretty solid for DIY and light shop work. These are not pro shop monsters you hammer all day into thick hardened plate, but for automotive, home metal fabrication, and general repairs, they’re more than enough. If you use proper speed, pressure, and lubrication, they hold up. If you just slam them at full RPM into stainless with no oil, you’ll cook them like any other bit. So the performance is there, but you still have to do your part.

This kit is a full jobber-length index: you get 115 bits split into fractional, letter, and number sizes. Concretely, that’s:

• 29 fractional bits from 1/16" to 1/2" in 1/64" increments
• 26 letter sizes from A to Z
• 60 numbered sizes from #1 to #60

So if you’re doing anything that calls for specific tap drill sizes or fitting odd hardware, you’re covered. That’s the main draw here versus those basic 13‑piece or 21‑piece sets: you stop playing the guessing game and just grab the exact size the chart calls for. I used the numbered bits for tapping a few M4 and M6 holes in mild steel, and it was nice not having to fudge it with the “closest” metric/imperial bit I had lying around.

The bits are advertised as M35 cobalt HSS with a 135° cutting angle and a Titanium Aluminum Nitride type finish. In practice, that means they’re meant to handle hardened steel, stainless, cast iron, and the usual softer stuff like aluminum, plastics, and wood. I mainly tested on mild steel angle, some stainless bolts, and a case-hardened suspension bolt, plus a couple of holes through pine and plywood. They all cut without real drama as long as I kept the speed reasonable and used a bit of cutting oil on metal.

The whole kit comes in a metal index box, not plastic, and every slot is labeled with the size. There’s a simple fold-out layout inside, so you’re not guessing which row is which. Nothing fancy, but practical. For the price, the sheer coverage of sizes and the fact that the box is metal and not flimsy plastic is what stands out. You’re not getting premium-brand finishing, but you’re also not stuck with a half-empty set after one project.