A drill bit set keeps several useful sizes in one case, making it easier to match the bit to the material and hole. The right set can also save time when a job calls for a different diameter halfway through the work.

Knowing the common drill bit set options and their applications helps buyers choose useful tools without paying for pieces they may rarely use.

Here are eight common drill bit set types and where each one works best.

1. High-Speed Steel Drill Bit Sets

High-speed steel, often called HSS, gives buyers a dependable option for routine drilling. It works well in mild steel, aluminum, brass, plastic, and many wood applications. Maintenance teams and homeowners often keep an HSS set nearby because it covers a broad range of everyday jobs.

Many HSS sets include jobber-length bits in fractional sizes. Some also include number or letter sizes for tapping, clearance holes, and machine work. A 135-degree split point can help the bit start with less wandering on flat metal.

HSS works best when the material doesn’t create heavy heat. Use a suitable drilling speed and apply steady pressure. Cutting fluid can help the edge stay cooler when drilling metal.

Choose HSS when you need an affordable set for mixed materials and moderate use.

2. M42 Cobalt Drill Bit Sets

Cobalt drill bits excel at penetrating tough metals that quickly dull standard HSS bits. M42 cobalt, with a higher cobalt content than M35, maintains hardness at high temperatures, making it reliable for stainless steel, cast iron, titanium, and work-hardened metals.

Professional fabricators often choose M42 cobalt bits for demanding tasks. These sets come in fractional, metric, number, letter, jobber, or stubby sizes, suited to different hole diameters and clearance requirements.

Use cobalt bits at appropriate speeds; running them too fast causes heat buildup and reduces their lifespan. Apply steady pressure to keep the cutting edges working.

Choose cobalt when HSS bits dull quickly or when working with materials prone to work-hardening.

3. Solid Carbide Drill Bit Sets

Solid carbide offers high wear resistance and strong edge retention. Machine shops often use carbide for hardened steel, cast iron, abrasive alloys, and repeated production holes. Carbide can also support accurate drilling when the equipment holds the bit and workpiece firmly.

A stable setup matters because carbide doesn’t tolerate side pressure well. Vibration or poor alignment can chip the cutting edge. A CNC machine, a milling machine, or a sturdy drill press usually provides carbide with the support it needs.

Carbide sets cost more than HSS or cobalt sets. They can earn their place when hole quality and tool life matter more than the initial price.

Choose carbide for rigid machining setups and demanding materials. Avoid it for handheld drilling where the bit may flex.

4. Jobber-Length Drill Bit Sets

Jobber-length bits provide a useful balance between reach and rigidity. Their standard length works for many shop, maintenance, and repair jobs. Most general-purpose drill indexes use this format.

You can find jobber sets in HSS, cobalt, and carbide. The word “jobber” describes the length rather than the cutting material. Buyers should still match the bit material to the workpiece.

A jobber set works well for holes that don’t require extended reach. It also fits many drilling setups without creating excess flex.

Choose a jobber set when you need a broad range of sizes for standard-depth holes.

5. Stubby Drill Bit Sets

Stubby bits, also called screw-machine-length bits, have shorter bodies than jobber bits. The shorter length increases rigidity and helps the bit resist deflection. It also fits into tight spaces where a standard bit leaves little room for the chuck.

Automotive repair and equipment maintenance often benefit from stubby sets. Fabricators may also use them when accurate starts matter. Shorter bits have less length available to bend as they enter the metal.

Stubby bits don’t work well for deep holes. Their value comes from control and compact size.

Choose a stubby set when clearance feels limited or when a rigid bit can improve hole placement.

6. Silver and Deming Drill Bit Sets

Silver and Deming bits cut holes larger than the shank size. Most use a 1/2-inch reduced shank, allowing a compatible chuck to hold larger cutting diameters. Common sets often start around 9/16 inch and continue through 1 inch.

Fabricators use these sets for larger holes in plate, brackets, and structural parts. They can also help enlarge an existing hole when the setup supports the larger cutting load.

Large diameters require slower drilling speeds. The machine also needs enough torque to keep the bit cutting without stalling. Securing the workpiece reduces chatter and helps protect the cutting edge.

Choose Silver and Deming bits when the hole diameter exceeds the capacity of a standard straight-shank set.

7. Left-Hand Drill Bit Sets

Left-hand bits rotate counterclockwise. Mechanics and maintenance teams often use them to remove broken screws, studs, and bolts. During drilling, the reverse rotation may catch the damaged fastener and turn it out.

Some kits pair left-hand bits with extractors. The bit creates a centered opening, and the extractor grips the fastener after drilling. Starting near the middle helps prevent damage to the surrounding threads.

Low speed gives the operator better control. A center punch can help establish the starting point before the bit touches the metal.

Choose a left-hand set for broken fastener removal and repair work.

8. Specialty Drill Bit Sets

Specialty sets focus on one type of hole or material. Step drill sets work well in sheet metal, while countersink sets prepare recessed screw seats. Tap-and-drill sets pair each tap with a matching drill size.

Some specialty kits include long-reach bits, micro bits, spot-weld cutters, or masonry bits. The value comes from having matched tools for one repeated task.

A specialty set often makes sense after a shop identifies a recurring need. Buyers gain more useful pieces and avoid filling a case with sizes that rarely leave the index.

Choose a specialty set when one application appears often enough to justify a dedicated kit.

What Matters When Comparing Drill Bit Sets

Piece count may attract attention, but it doesn’t show how useful the set will feel in practice. A smaller case may serve you better if it contains the sizes and materials your jobs require.

Before buying, check:

• The materials you drill most often
• The size range your work requires
• The available drilling depth
• The equipment that will hold the bit
• The need for fractional, metric, number, or letter sizes

Replacement access also deserves attention. Frequently used sizes can be worn faster than the rest of the set. Buying individual replacements may extend the index’s useful life and prevent unnecessary replacement costs.

Match the Set to the Application

The most common types of drill bit sets and their applications cover general repair, production work, large-hole drilling, fastener removal, and specialized tasks. HSS supports routine jobs, while cobalt handles tougher metal. Carbide is well-suited to stable machining setups where wear resistance matters.

Drill Bit Warehouse carries HSS, cobalt, carbide, left-hand, and specialty drill bit sets for professional and everyday use. Contact the team for help matching a set to your material, equipment, and hole requirements.