Drill Bit Types Demystified
In the past, choosing a hammer was simple. Today, the overwhelming number of options can leave even the most experienced craftsman feeling perplexed. The same can be said for drill bits. With advancements in tool technology, it’s important to understand the distinctions between different types of drill bits to avoid wasting money and using the wrong tool for the job. In this article, we’ll delve into the differences between black oxide, titanium, and cobalt drill bits, helping you make an informed decision.
Titanium Drill Bits: The All-Rounder
Titanium drill bits are made by coating high-speed steel (HSS) with titanium nitride (TiN) through a similar process to electroplating. This ceramic coating enhances the bit’s surface hardness, reduces friction, and provides a thermal barrier. The result is a drill bit that offers improved productivity, corrosion resistance, and a lifespan that is three to six times longer than standard bits. Titanium drill bits are suitable for drilling into iron, steel, aluminum, magnesium, and wood.
When it comes to general-purpose drilling in a production environment, titanium drill bits shine. The TiN coating aids chip flow through the flutes, which is especially useful for materials like aluminum that tend to stick to the bit. However, it’s worth noting that once the tip becomes dull, it cannot regain its cutting edge without recoating it with titanium nitride. Consequently, when the tip wears down, it’s often more cost-effective to replace the bit rather than attempt to refurbish it. While titanium bits are harder than cobalt, their cutting edges are only as deep as the coating itself.
Image: Drill bits – Titanium, cobalt, or black oxide?
Cobalt Drill Bits: The Heavyweights
Cobalt drill bits are made by incorporating 5-8% cobalt into high-speed steel alloy, resulting in an exceptionally durable bit. Unlike titanium-coated bits, cobalt is present throughout the material, making it ideal for drilling in highly abrasive and hard materials such as treated stainless steel, titanium, and cast iron. Thanks to their enhanced structure, cobalt bits can withstand the high levels of heat generated during drilling. This makes them a valuable choice for high-volume work where durability is essential.
It’s worth noting that most professionals don’t utilize cobalt bits for general drilling due to their cost and durability. The extra hardness allows manufacturers to reduce the groove thickness, thus increasing the strength of the drill bit. Additionally, cobalt bits can be sharpened without compromising their cutting ability. While cobalt drill bits may be more expensive than their titanium or black oxide counterparts, many professionals consider their toughness to be a worthwhile investment.
Image: Milwaukee Cobalt Bits
Black Oxide Drill Bits: Basic and Reliable
For those seeking an economical and versatile option, black oxide drill bits fit the bill. These bits undergo a heat treatment process at 950 degrees Fahrenheit to create a black oxide surface that resists rust and corrosion. In addition to reducing friction between the bit and workpiece, this coating accelerates the drilling process. Black oxide-coated bits can be used on a wide range of materials, including steel, copper, aluminum, brass, wood, and various synthetic composites.
Compared to standard HSS drill bits, black oxide bits boast a 50% longer lifespan and exceptional durability. Many professionals consider them to be the best general-purpose drill bits available.
Image: What is black oxide drill bit
Wrapping It Up
Now that you’re armed with knowledge about the differences between black oxide, titanium, and cobalt drill bits, you can make an educated choice for your specific drilling needs. If you have any tips of your own or want to join the conversation, feel free to leave a comment below or reach out to us on Facebook, Twitter, or Instagram. Happy drilling!