Best Drill Bits for Metal – We’ve used and/or tested dozens upon dozens of drill bits for practically every purpose throughout the years. We aimed to find the best drill bits for metal applications this time around. Hardened steel, stainless steel, aluminium, and other metals are among them. We wanted to determine which drill bits were best for drilling out tough nuts like those found in engine blocks. People frequently inquire about bits for drilling into rebar. These are the sections that we consult, and they should point you in the correct path.

Best Drill Bits for Metal

#01 – Drill America D/A29J-CO-PC 29-pc Cobalt Set





Drill America offers M42 cobalt bits that drilled through whatever we threw at them with ease. We chose their jobber bits as our finest drill bits for hardened steel after evaluating them with a variety of materials.

The bits have a 135° split point, which provides a good, consistent, and profitable drilling pace. For onsite drilling, the jobber length bits perform great in cordless drills. They’re built to the 907 National Aerospace Standard. You can drill up to 30% quicker with them than with standard M2 high-speed steel bits due to their hardness. Drill America’s bigger bits don’t have their shafts ground down, which gives them additional stiffness, but you’ll need a 1/2-inch chuck to use them.

When drilling strong, high-tensile-strength materials like stainless steel or titanium, use these bits. The D/A29J-CO-PC kit was chosen. It comes in a shatterproof casing with 29 pieces. The spherical enclosure makes removing the precise part you need straightforward.


  • WOW


  • Not worth the money



#02 – Irwin 29-piece Cobalt M-42 Metal Index Drill Bit Set



The Irwin 29-piece M-42 Cobalt bit kit is our favourite metal drill bit set for drilling tough metals and steels. To be honest, it isn’t the quickest drilling bit that wins us over. It has to do with the high-speed steel M42 and the superb casing.

Many low-cost cobalt drill bits are made of M35 steel, which contains 5% cobalt. The cobalt content of M42 steel is 8%. This increases its toughness. It also allows for faster drilling than M35. If you don’t plan on drilling hardened steel, Irwin supplies an M35 cobalt set.

This takes us to the situation at hand. If you perform a lot of drilling, the case in which your bits arrive is important.


  • Go slow and cutting oil
  • Great for drilling into steel
  • Very HAPPY with this profession grade bit


  • Sizes incorrect



#03 – Irwin Unibit Cobalt Step Bits



For any rapid thin metal drilling requirements, our crew selects Irwin Unibit Cobalt Step Bits. These parts have a substantially longer life due to the cobalt mix. We want step bits to last as long as possible because they are both costly and difficult to sharpen.

Irwin recommends Speedpoint for these parts. It speeds up the digging process and prevents wandering. We have to admit that one of the reasons they became our favourite metal step bits was because Irwin laser-etched the dimensions on the inside of the flute. They don’t wear out as soon as some of the other parts we’ve tried.


  • Great bits
  • Good step drill bit set


  • Not happy



#04 – Best Molybdenum Drill Bits—Viking Drill Bit & Tool Set




Molybdenum is a form of high-strength steel, and while it’s tough, it’s not as tough as, say, Cobalt. These Viking Drill & Tool bits, on the other hand, are outstanding and easily cut through weaker metals. This 29-piece set includes gold dioxide-coated pieces of various sizes to help reduce heat generated by friction.

One reviewer said, “We used two of the bits to drill two holes in a stainless steel table top.” “It was shocked at how well it went.” Another satisfied customer stated that drilling with these bits was “like drilling through butter.”


  • Nice set
  • Awesome quality and incredible deal
  • Extremely sharp!


  • Replace your cheap bits now
  • Very disappointed



#05 – Best M42 Drill Bits—STROTON Metal Drill Bits




These STROTON drill bits, which come under the category of M42 bits and have an 8% coating, have a greater Cobalt coating concentration. This set includes 19 straight shank parts that may be used to drill holes in a broad variety of metal items.

You’ll have no trouble making holes in everything you need with them if you use a steady hand, patience, and a little lubrication. “There’s nothing like taking a drill bit and watching it take on everything I throw at it,” one satisfied customer commented. “The cutting edge has a step-like evolution and a sharp, well-engineered tip. There is no drifting, and it is expertly piloted.”


  • Excellent drill bits and customer service!
  • Good value for the quality, good customer service
  • Good Set of Drills


  • Impressive performance
  • Top quality, no real complaints


#06 – Best Round Shank Drill Bits—DKIBBITH Drill Bit Set




This compact set is composed of HSS with a gold oxide finish and is ideal for mild or softer steels like aluminium. Because of the bits’ distinctive form, they may be used to drill holes that hide flat-top screws and allow them to sit flush against the surface. This countersinking isn’t suitable for every project, but it comes in handy when you need a tapered angle.

“Usage in my mill or drill press is great,” one buyer said, “and Really expect this set to last a long time if used properly and not on tougher materials like stainless steel.” “The end finish, which is so far outstanding without any noise, is controlled by the speeds and feeds or downward pressure.”


  • Metal case with foam rubber inserts is a very nice feature
  • Exactly what I needed, and a nice case for storage
  • Quality made, fun to use


  • These work on soft brass. I have used them on nothing else


#07 – Best Large Drill Bit Set—EnerTwist Drill Bits




This EnerTwist drill bit set includes 230 bits with a 118° angle and a titanium finish in diameters ranging from 1/2-inch to 3/64-inch. The friction-reducing coating on these bits, according to the company, allows them to outlive competition items by up to six times. And, to keep things organised, the case they come in is labelled with the various bit diameters, so you won’t have to scrounge around aimlessly for a new size.

“They just don’t become dull after using them on a variety of materials, including wood, brick, aluminium, cast iron, PVC, and plastic,” one customer noted, verifying that “they are high-quality, long-lasting drill bits.”


  • Bits feel sturdy


  • Low expectations weren’t low enough!



#08 – Best Hex Shank Drill Bits—Amoolo Drill Bit Set




This 16-piece package covers the most typically needed bits as well as some miniscule sizes, such as 1/16-inch and 3/32-inch, if you’re in need of hex-shanked drill bits. While the bits in this set aren’t designed for use on cast iron or heavy-duty steel, they are ideal for softer alloys.

“We got these to work on gunmetal,” says the customer “one buyer wrote “They work excellent if you grease the bit before using it with metal!”


  • Good product
  • Well Made


  • Fair price and great delivery makes it a good purchase


#09 – Best Black Oxide Drill Bits—DeWALT Drill Bit Set



You can acquire a really strong set of bits for less than $10 that are both budget-friendly and come from a respected brand. The drill bits in this DeWALT set are black oxide-coated and have a parabolic flute shape, which improves chip ejection and results in a smoother hole.

However, each bit has a 31° angle, making it less intense than a real parabolic flute bit, according to the maker. One reviewer stated, “They’re beautifully built, sharp, and cut extremely well in steel.” “They’ve been fairly durable so far, and I haven’t had to resharpen them.”


  • Nice set, wrong description


  • Cheap but dependable drill bits


#10 – Best Step Drill Bits—CO-Z Drill Bits



Step drill bits, such as the ones included in this CO-Z set, are perfect for thinner sheet metals and softer materials such as wood. They’re all various sizes with a spiral flute pattern and are coated with Cobalt. Hundreds of reviewers have used these bits to drill through thin metal tiles, handle plastic and sheet metal on autos, and create drainage holes in metal planters.

“The step drills cover many diameters, and they look sturdy, durable, and can easily pierce various metals,” one delighted customer commented.


  • Great Customer Service!
  • Very good quality drills


  • Not made for heavy use


Metal Drill Bits Buying Guide

Drill bits designed for metal surfaces have particular coatings or are built of specific materials that can withstand the friction, heat, and resistance encountered while drilling into metal. Soft carbon tool steel bits are not designed for this type of operation, and they can break under pressure, resulting in damaged tools and injuries.

You’ll want to look for bits made of High-Speed Steel (HSS) and Cobalt High-Speed Steel when looking for pieces that can take this level of drilling. For tougher metals, such as cast iron, the latter is more durable, but the former is preferable with softer materials. Titanium, black oxide, diamond, and other metal coatings

Drill bits with a cobalt mix are clearly the finest for hardened metal or steel. These cobalt drill bits are made from an alloy that contains 5%–8% cobalt. Because cobalt is a component of the steel, the bit’s hardness is not affected by a coating (like titanium bits). It’s there throughout the piece.

Another significant benefit is that you can sharpen these pieces. This is noteworthy when you consider that cobalt drill bits are substantially more expensive than other types of twist drill bits. These bits, unlike black oxide or titanium bits, should be saved for when you really need them.

Add a drop of oil to the metal before drilling a hole with a cobalt bit to keep the cutting edge colder as it cuts.

What Exactly Is Hardened Steel?

When we talk about hardened steel drilling, we’re talking about medium or high carbon steels that have been heat-treated and tempered. Hardened steels are tough and resistant to wear, corrosion, and abrasion. Hardened steel makes up a large portion of the steel used in mechanical engineering, energy generation, and transportation. The greatest metal drill bits might be made for these hardened steel applications, or they could be made for speed in softer carbon steels.

Steel, stainless

Stainless steels are steel alloys that include at least 10.5 percent chromium and are available in a variety of grades. It has various commercial applications, including cookware, cutlery, household appliances, construction fasteners, and medical equipment, because to its rust and stain resistance, high sheen, and low maintenance.

Regardless of the variations in appearance or chemical makeup, both hardened steel and stainless steel are extremely tough to drill through. The easiest approach to obtain good results is to use a drill press.


Titanium is a metal (Coating)

Titanium nitride-coated drill bits are resistant to corrosion and friction. It outperforms black oxide in terms of increasing surface hardness and lowering heat when drilling into metal. We consider them to be the absolute minimum for metal drilling.

It’s important to understand that titanium nitride merely coatings the bit. The cutting edges will need to be replaced when the coating wears away. If you want these bits to last, don’t use them to drill hardened steel or stainless steel.

Copper (Steel Blend)

Our finest Cobalt drill bits for metal drilling are constructed with an 8% cobalt alloy (M42).


We understand if we missed something along the road. We must draw the line and complete the article at some point. With that stated, tell us what you believe the greatest metal drill bits are. Leave a remark, especially if you have a “hero” tale of how a certain passage helped you out of a bind.

Related Tags:

About the author

Nancy M. Lach

Leave a Comment