HSS Drill Bits vs Cobalt Drill Bits

HSS Drill Bits

HSS are heat resistant and hardwearing drill bits. The huge concentrations from nickel and chrome in the stainless steel makes sure that HSS bits are durable and strong. HSS drill bits can safely drill through hardwood, plastic and some types of metal.

Even at high speed, operating them is quite safe, (RPM) and if well maintained, they are capable of providing a long lasting performance.

Through the years, HSS drill bits have the tendency of becoming blunt and will required to be re-sharpened. Most times, the sharpening tools are not available.

HSS Drill Bits

Via: @nulinetools

If therefore, you’re planning on using HSS drill bits for extended periods at high RPMs, you might be required to use cutting fluids to cool the bits.

Cobalt Drill Bits

Cobalt bits are made from a combination of steel (or a type of alloy) mixed up with a percentage of cobalt. The combination ratio is about 5 – 7%.

Cobalt drill bits have a 1495°C melting point and a 2927°C boiling point, and this makes them ideal for use at high temperatures. Through the combination of small amounts of cobalt and an alloy, the results are high performance drill bits.

Cobalt drill bits are quite strong. Their performance is mostly at higher speeds than the standard HSS drill bits.

They have an ability to withstand high temperatures, meaning that cobalt drill bits can perform for an extended period without the need for a cutting fluid or a cooling element.

They are mostly used for cutting through abrasive and hard materials. Cobalt bits have the ability to cut through the hardest of metals, including cast iron, bronze, titanium and stainless steel. They can also easily cut through weld seams.

Via: @harddrillbits

The cutting edges of a high quality cobalt bit will last for a longer duration compared to that of a standard HSS bit.

Just like it is in other HSS bits, Cobalt drill bits are resistant to corrosion, meaning that they are able to maintain their functional condition in any storage or performance conditions they are exposed to.

One downside of cobalt drill bits is that they can be brittle. If you drop your cobalt drill bits or do not carefully maintain them, they will break, and this can be quite an expense.

HSS vs Cobalt Drill Bits


HSS drill bits are bets suited for drilling in soft materials like wood, plastic and light metals. Drilling using a dull bit will slow down the process which will result to overheating. HSS drill bits need to be sharpened using a bench grinder, or better by a drill doctor.

HSS drill bits are bets suited for drilling wood

Via: @axminstertools

Cobalt drills are suitable for drilling through tough materials such as hardened metals or stainless steel.


A high-quality HSS bit will work nicely and precisely and can be relied on, if you are able to keep them sharp, HSS drill bits are a reasonable investment. A good HSS bit will be quite okay if you get it from a quality and reliable source.

For DIY home applications, cobalt bits come with a much better “hot” hardness. This is an important feature.

A lot of non-industrial users who use hand driven drills can blunt the HSS bit’s cutting edge easily. This is because of the uncontrolled feeding or imperfect alignment.

HSS tools exhibit strength and sturdiness and are able to withstand an intermittent or cyclic loading. This performance of HSS tools, however, can be improved further through a simple application of a coating.

The cobalt-base super alloys on the other hand, originated from the Stellite® alloys with roots in early 1900’s thanks to Elwood Haynes.

Cobalt alloys are mostly used for the following reasons:

  • They have a high resistance to hot erosion
  • Cobalt alloys have a higher melting point than the HSS alloys. This means that cobalt drill bits are much better in absorbing stresses that are as a result of extremely high temperatures
  • A Cobalt alloy will exhibit a good thermal welding ability and resistance to fatigue

Why choose a cobalt drill bit over HSS?

It’s important for your safety and the safety of your tool that you use the most appropriate drill bits for every job. Cobalt drill bits are stocked together with some other consumer favorite choices, including titanium nitride, titanium coated or tungsten carbide bits.

Cobalt Drill Bits

Via: @kmtznr

Each one of these drill bits comes with special strengths and consequently, weaknesses. This is why you should be extra careful on the small details when buying either of them.

The sturdiness of cobalt drill bits shows that drill bits are appropriately suited for the tough functionality of cutting through steel. Cobalt bits are however, not suited for other classification of general applications.

For the less intensive functions, such as drilling through plastic, wood or soft metals, an HSS drill bit will be better suited for the job.

Via: @jelboglobal

Via: @jk.custom.guitars.and.repairs

Both HSS and cobalt drill bits need to be regularly maintained and well taken care of for the appropriate performance delivery. Even among hardest wearing of materials, becoming blunt or dill over time is imminent if they are not properly taken care of.

Adhere to the appropriate drilling techniques to increase the lifetime of any drill bits.

If you are not quite sure of the equipment to go for between HSS or Cobalt Drill Bits, do not shy away from consulting with an expert.

HSS vs Cobalt Drill bits – Conclusions

The best choice of a drill bit would be an affordable bit that does not require cutting oils even at the lowest of speed. This means that it does not get blunt or overheated.

The HSS bits are, in some applications, very well suited. When it comes to cutting plastics and wood, they exhibit a sharper and finer edge.

Cobalt drill bits on the other hand, are the best for home use or cutting through hard metals. They rarely get bunt and will never overhead no matter how low the speed of their operation is.

They are a bit more expensive than HSS drill bits, but with a performance this good, I’d say that they are worth every penny.

HSS vs Cobalt Drill Bits

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