HSS Drill Bit and Its Uses

HSS drill bits, also called jobber drill bits, are widely used and available in various sizes. Which applications are they best suited to, and when should you opt for a different type of drill bit?

What is an HSS Drill Bit?

A High-Speed Steel (HSS) twist drill bit is a cutting tool with two angled cutting lips at the tip and spiral grooves along the body. HSS bits are the most economical general-purpose option currently on the market. You can use this versatile drill bit on various materials, like plastic, metal, and hardwood, and you can resharpen it to extend its lifetime.

HSS drill bits are suitable for both hand drilling and machine drilling. They’re also quite tough and heat-resistant, which makes them suitable for high-speed drilling applications. These twist drill bits typically have two cutting edges shaped to have an included angle of 118°.

Sometimes, HSS drill bits are coated with titanium or black oxide. This improves the surface hardness and reduces friction, rendering the drill bit more wear-resistant and further extending its lifespan.

Resharpening reduces a drill bit’s cost since it can be used longer. Not all drill bits can be sharpened, however. For instance, it may not be practical sharpen very small drill bits (below 1/16-inch). In the case of coated bits, during the re-sharpening the coating at the point angle will be removed.

HSS Drill Bit Uses

So, what is an HSS drill bit used for?
HSS drill bits are highly versatile and can be used in various applications. Below is an overview of the most common ones.

1. Metalworking

HSS drill bits are incredibly well-suited to metalworking. Go to any metalworking shop, and you will find a set of HSS jobber bits. These drill bits comprise a carbon steel alloy with vanadium and chrome added, making it highly wear-resistant and hard. HSS drill bits easily cut metals like steel, iron, brass, aluminum alloy, and copper.

HSS drill bits are also more resistant to heat build-up during high-speed operations when compared to other types of drill bits. They can withstand a working temperature of up to 650°C (1202°F), which is quite impressive.

You can use the HSS drill bits to drill holes, enlarge existing holes, and create pilot holes for threading, among other tasks.

2. Woodworking

HSS drill bits are commonly used for woodworking because they’re versatile. They can be used on most other materials you would use during woodworking projects.

These drills are also affordable and easily cut through hardwood and drywall. While high carbon bits are cheaper, they can get dull quickly, especially when working with hardwood due to excess heat.
Also see: Difference between Metal and Wood drill bits

3. Drilling Plastic

Standard HSS drill bits can easily drill through various types of plastic, like PVS, Plexiglas, acrylic, and nylon. They’re very sharp, so when drilling through plastic, it’s best to use a drill bit that’s been used at least once. This prior use dulls the bit slightly, preventing it from cutting into the plastic. When the bit cuts into the plastic excessively, it creates burrs.

If you are using a cordless drill, keep in mind that it could easily wander, enlarging the hole and potentially elongating it along an unwanted axis.

4. Drilling into Composite Materials

Drilling through composite materials is typically more challenging than drilling through metal, wood, and plastic. Composite materials include fiberglass, carbon fiber, laminate components, and resins.

When drilling through laminate materials, the drill bit could cause the fibers in the laminate to break apart and splinter. Heat build-up from the drilling process could also heat the resin above its service temperature, causing delamination and other problems.

So, when drilling through composite materials, it is essential to ensure that the drill bit and drilling speed match the material requirements.

HSS drill bits are ideal for drilling through composite materials since it’s pretty sharp, thus minimizing friction during the drilling operation. Less friction decreases the heat build-up. The friction is further reduced when the HSS drill bit is coated with black oxide or titanium, decreasing the heat build-up.

A sharper drill bit is also less likely to break existing fibers apart, making the drilling operation more precise and less destructive.

5. Removing Broken Screws

HSS drill bits are far harder than most bolts and screws. This makes them ideal for drilling into broken screws to remove them. Various methods are available to remove a broken screw. Still, the fastest, most effective way is typically to drill into it.

Using a wear-resistant drill bit, like the HSS drill bits, with a diameter slightly less than the broken screw, drill lengthwise into the screw. Make sure that this hole extends the entire length of the screw. Once the hole is completed, use a screwdriver or chisel and hammer to pick the bits of screw still left in the hole, removing them as you go. You could also drill out the entire screw, enlarging the hole diameter.

If you are going to use an extractor to remove the broken screw, you will still need a drill bit to make the initial hole and HSS bits are perfect for the job.

6. Electrical & Plumbing Jobs

You often have to drill through drywall and masonry in plumbing and electrical applications. Having one drill bit that can handle both these materials reduces costs and saves time on site. HSS drill bits are ideal for this since they easily handle drywall and are excellent for drilling wood, plastic, and metal, and they can even drill through masonry.

They’re wear-resistant and heat-resistant, so they’ll withstand most of the punches the job will likely throw at them.

HSS drill bits also work in hammer-action drills, typically used when drilling through masonry. However, I highly recommend using a masonry bit, preferably with an SDS shank for masonry work.

7. DIY and Home Improvement Work

When working on DIY and home improvement projects, you want versatile multi-tools, not specialized, single-application tools.

The HSS drill bit is the Leatherman of the drilling world, suitable for most common applications, cost-effective, and incredibly wear-resistant. So, if you have a set of HSS drill bits in your toolbox, you can probably get most jobs done with only one drill and one drill bit.

If you’re making it work really hard, it might get a bit dull, but it’s relatively easy to resharpen and carry on working.

8. Craft Work

HSS drill bits are available in a wide range of diameters, including really fine drill bits measuring as low as 1/16” (Ø1.60mm) or less. These drill bits can be used for incredibly precise work, ideal for crafting applications. Examples include jewelry making, sculpting, and other art and craft applications.

9. Construction and HVAC

In construction and HVAC (heating, ventilation, and air conditioning) applications, you want to do the job quickly, with the least mess and fuss. When using HSS drill bits, you can drill through various materials without creating burrs and with minimal vibration on the workpiece. This ensures precise work, which is essential for neat installations.

HSS drill bits are also available in self-tapping and step drill bits, commonly used in construction and HVAC applications.

10. Automotive Industry

HSS drill bits are often used for general drilling in automotive applications. These drill bits make drilling quick and easy since they suit high-speed drilling. They also offer precise drilling and can cut through all materials used in automotive applications.

Titanium vs. HSS vs. Cobalt Drill Bits

Titanium drill bits are HSS drill bits with special coatings. When covering an HSS drill bit with titanium nitride (TiN), we call it a titanium drill bit. This PVD coating (physical vapor deposition) increases the bit’s surface hardness and reduces friction during drilling. Titanium drill bits have a longer life span and greater corrosion resistance than standard HSS drill bits. They can also drill at higher speeds.

However, Titanium drill bits can’t be resharpened without recoating them once dulled. This process is expensive and can’t be done without specialized equipment, so replacing the drill bit once dulled makes more sense.

Cobalt drill bits (not cobalt-coated) are made of high-speed speed alloyed with 5-8% cobalt. These drill bits are excellent for drilling metals since they are incredibly heat resistant. While these drill bits make mincemeat of most metal applications, they’re expensive. So, they’re not typically used for general metalwork. Instead, they’re used for specialized, high-speed production applications.

The key difference between titanium and cobalt bits is that the one is a coating while the latter is made of a special cobalt alloy steel. You can see more details here.

FAQ

Can I Use an HSS Drill Bit for Masonry?

You can use HSS drill bits for light masonry work. They’ll drill through bricks, which is excellent for general applications. However, they are not suitable for drilling concrete and stones.
It would be best to use a masonry drill bit when you need to do a lot of drilling since HSS drill bits will quickly dull when used on masonry.

Can You Drill Tiles with HSS Drill Bits?

HSS drill bits won’t work well when drilling tiles. It would be best to have a special carbide tile bit or diamond-tipped core bit to cut through the ceramic tile without breaking it.