Cobalt Drill Bit Set, 29Pcs M35 High Speed Steel Bits for Hardened Metals, Stainless Steel, Cast Iron and Wooden Plastics, with Metal Index Storage Box, 1/16"-1/2"

Very impressive on its functionality. I purchased before Milwaukee and Dwall drills and they did not performed correctly, as a matter of fact, they got broke and it took kind of long to perform the drilling. With this MACKCPIP cobal drill bit set, i drilled like 5 holes with out any issue. Except for the smaller drill bit got broke, but the other one i used worked more then great!!!

This cobalt drill bit set performs really well on harder materials. The bits stay sharp and cut cleanly when used with proper speed and pressure. Sizes are accurate and the set covers most common needs. Used them for metal drilling and they handled the job without overheating or dulling quickly. Great value set for DIY or shop use and a nice upgrade from standard bits.

I use the MACXCOIP cobalt left hand drills to remove broken bolts, studs, and fasteners. They’re very hard so they are subject to breaking. Don’t use them too agressively or with a very high speed on metal. They seem to be good quality and very sharp. These are special purpose application only and should last.me for many years. The set came in a plastic index case to keep the jobber-length bits together and easy storage. Good value.

Excellent! Drilled-out a broken screw super easily

bits are sharp and drills well

Good high quality cheap drill bits that work excellent

The MACXCOIP 13‑Piece M35 High Speed Steel Cobalt Drill Bit Set looks solid in the listing, but in practice these bits are very basic and don’t perform well on tougher materials like stainless steel. Wobble There’s a noticeable wobble when drilling, especially with the smaller bits. They don’t track straight, which makes precision work difficult. Drillability Despite being advertised for hardened metal and stainless steel, I couldn’t get through a 1/4” stainless steel plate even using a high‑power corded drill. They dull quickly and lose bite almost immediately on harder metals. Breakability These bits overheat fast, and once they get hot, they deform and snap into pieces if you apply even moderate pressure. Breakage is a real issue. Ease of Use They’re fine for soft materials like wood, plastic, or aluminum, but anything beyond that becomes frustrating. Frequent stopping to cool the bit or swap to a new one slows everything down. Durability Durability is the biggest weakness. The M35 label suggests higher heat resistance, but in practice they wear out and break far too easily. Look The set looks decent in the index storage case, and the bits have a clean finish out of the box, but the appearance doesn’t match the performance. Customer Service After posting this review as a 2/5 review the seller/manufacturer reached out to me without request offering me a full refund, no questions asked, no request to take down or modify my reviews. That said, I felt that was a class move and shows great customer service which deserves a star on its own so I’ve increased my score to 3/5. Overall, with the star added for great customer service this is a 3/5: a basic cobalt drill bit set that’s okay for light materials but fails quickly on stainless steel, overheats, and breaks under pressure. You get what you pay for here.

I had a use case where a machine screw had broken off in a location that wasn't easy to access. I decided versus pulling the piece of equipment apart to improve access, I'd spend the money on a set of these with the hopes it would catch as I was drilling out the broken off screw. The screw broke during installation, so I wasn't worried about rust or anything like that, and the roll of the dice paid off. As I slowly increased the size of the bits, one finally caught and backed it out. I replaced the machine screw with a new one and job done. This set saved me about an hour of disassembly and for me, that made the set worth the price. I don't know long-term how they'll hold up, but for me, these will be used infrequently and as I mentioned, they've already paid for themselves, so future use is just money in the bank. The case is nice and the quality seems good, so no regrets here.

For so long I went with just whatever came with the drill. These bits are so hard, and with a little bit of oil cuts super well and stays sharp. Left hand is extra handy to drill out broken/welded in screws. Love them. Would bring them to bed if I were allowed.

Bastante satisfecho con la duración, es similar a las brocas Milwaukee titanio pero a un precio menor para ser de cobalto esperaba que duraran un poco más pero aun así muy satisfecho

No era lo que esperaba muy caras y son de medida muy pequeñas, no llegan ni alos 10mm. Yo buscaba de 8mm. sta 14mm. Pero la descripción está muy confusa

Nothing

The drill index (the case) is substandard: doesn't have decimal inch markings and the tiers don't fold properly when opening or closing the lid.