Choosing the best bits for drilling steel is an essential task when you’re handling such a robust material. As a rule of thumb, it’s advisable to opt for cobalt, carbide, and high-speed steel (HSS) drill bits. Cobalt drill bits are a popular choice due to their excellent heat resistance and durability, making them perfect for drilling through hardened steel. HSS bits, although less durable than cobalt, are more cost-effective and can handle standard drilling tasks with ease. However, for the most demanding jobs, you might want to consider carbide drill bits. They offer excellent hardness and can withstand high temperatures, which makes them the best bits for steel when dealing with exceptionally thick or hardened alloys.
The design of the best bits for steel is also crucial to their performance. Split point tips, for instance, are excellent for drilling steel as they reduce the need for a center punch and prevent the bit from ‘walking’ across the material. Furthermore, a 135-degree point angle is commonly recommended for drilling steel to minimize the pressure applied on the tip and prevent it from breaking. Coatings like black oxide, titanium nitride, or diamond powder can further enhance the performance of the drill bits, extending their lifespan and increasing their corrosion resistance.
Let’s delve deeper into carbide, arguably the best material for the toughest steel drilling jobs. Solid carbide bits, although relatively more expensive, deliver superior performance due to their extreme hardness. This toughness makes carbide bits more resistant to wear and tear, which is essential when working with hard materials like steel. Meanwhile, carbide-tipped bits, where only the cutting edge is made of carbide while the rest is usually steel, offer a balanced blend of durability and affordability. The carbide tip provides the hardness necessary to drill through steel, while the steel body ensures the bit is not as brittle as a full-carbide bit. These characteristics make carbide, in both its solid and tipped forms, one of the best materials for crafting the best bits for steel.
DEWALT Cobalt Drill Bit Set (DWA1240)
 This 14-piece set is made from industrial-strength cobalt for longevity. The bits feature a pilot point and split tip design that starts on contact and eliminates bit walking for more precise hole placement.
Bosch CO14B 14 Pc. Cobalt M42 Drill Bit Set
With cobalt design and a no-skate tip, these bits from Bosch are highly durable and provide clean, accurate holes. The hard case also includes size markings for easy identification and organization.
Makita T-01725 Contractor-Grade Bit Set
Makita’s 70-piece set is not only great for steel, but it’s also compatible with wood and plastic. It comes in a compact, durable case and features ultra-lokk hex shanks to prevent bit spinning.
Drill America DWD29J-CO-PC Cobalt Steel Drill Bit Set
This set is designed for drilling tough, high tensile strength materials like stainless steel. It includes a selection of 29 jobber length drill bits, ranging from 1/16 to 1/2 inch.
Irwin Tools 3018002 Cobalt M-35 Metal Index Drill Bit Set, 29 Piece
Irwin Tools has a reputation for high-quality hardware. This 29-piece drill bit set is made from M-35 cobalt steel alloy, which is ideal for tough jobs like drilling through steel.
Milescraft 2320 Metal Stubby Drill Bit Set
For drilling in confined spaces, this Milescraft set is an excellent choice. It contains three extremely short bits, ideal for working in tight spots where regular bits can’t reach.
COMOWARE Cobalt Drill Bit Set- 15Pcs M35 High Speed Steel Twist Jobber Length for Hardened Metal
These bits are made with 5% cobalt, which provides high heat resistance and extends the bits’ lifespan. The twist design increases cutting speed.
Neiko 10193A Titanium Step Drill Bit Set
This set includes three step drill bits, which allow you to drill multiple hole sizes with a single bit. The bits are coated with titanium for added durability and a longer lifespan.
beyond by BLACK+DECKER Drill Bit Set, 14-Piece (BDA14BODDAEV)
Black & Decker’s set comes with 10 pieces and a compact storage case. Although not exclusively designed for steel, the high-speed steel (HSS) construction can handle mild steel and other materials.
Chicago Latrobe 550 Series Cobalt Steel Jobber Length Drill Bit Set
This high-end, heavy-duty set includes 15 bits in various sizes. Each bit is made from cobalt steel, which provides excellent heat and wear resistance.
Choosing the best drill bit depends on the task at hand. Harder materials like steel require robust bits, preferably made of cobalt or titanium-coated bits. The drill bits in this list are all available on Amazon and have been highly rated by customers for their performance and durability. Please remember that drill bit performance can also be impacted by the quality of your drill, so ensure that your equipment is up to the task.