Milwaukee Cobalt Drill Bit

The Milwaukee Cobalt Drill Bit, model 48-89-2310, has been a recent addition to my tool collection, and it has had its fair share of ups and downs. Designed specifically for hard metal applications, this drill bit promises enhanced durability and longevity, which are qualities that any serious DIYer or professional would appreciate. However, my experience with it has been a mixed bag, shedding light on both its strengths and weaknesses.

Design and Build Quality

Right out of the package, the drill bit feels solid and well-made. The cobalt alloy construction is evident, and it’s clear that this bit is designed to last longer than standard high-speed steel (HSS) bits. The variable helix design and the quad-edge tip are notable features that aim to reduce heat buildup and facilitate faster drilling. The 135° split point tip is intended for precise starts, minimizing the risk of the bit walking during use. These features are particularly appealing for those who need to drill into hard metals like stainless steel and cast iron.

Performance in Various Materials

I first put the bit to the test on a piece of 1/8” thick stainless steel. The initial performance was impressive. The split point tip did an excellent job of starting the hole precisely where I marked it, and the bit cut through the metal with relative ease. However, after just a couple of holes, I noticed a significant drop in performance. The bit started to produce smaller chips and required more pressure to continue cutting. By the third hole, the bit was noticeably dull, making the task increasingly difficult. This was disappointing, especially considering the bit’s premium price point.

Switching to a different project, I used the bit on 1/4" thick mild steel. Again, the initial performance was commendable. The bit created clean, precise holes with minimal effort. However, similar to my experience with stainless steel, the bit began to lose its edge after several holes. This time, I was more diligent about using cutting oil and maintaining a slow drill speed, but the bit still dulled faster than I expected.

Versatility in Applications

One of the selling points of this drill bit is its versatility. It’s marketed as being suitable for wood, stainless steel, metal, plastic, and PVC. In my tests, the bit performed admirably on softer materials like wood and plastic. Drilling through a wooden beam was a breeze, and the bit maintained its sharpness throughout the task. Similarly, it cut through PVC with ease, leaving clean, precise holes. However, given that this bit is specifically designed for hard metal applications, its performance on softer materials, while good, is not the primary concern.

Durability and Edge Retention

Durability is where the Milwaukee Cobalt Drill Bit falls short. Despite its robust design and premium construction, the bit’s edge retention is disappointing. After just a few holes in hard metal, the bit dulls significantly, making it less effective and more challenging to use. This is particularly frustrating for those who need to drill multiple holes in hard materials, as the bit’s performance declines rapidly.

Ease of Use and Craftsmanship

The 3-Flat Secure-Grip shank is a thoughtful addition, ensuring that the bit stays securely in the chuck during use. This feature is particularly useful when working with high-torque drills, as it prevents the bit from slipping. The craftsmanship of the bit is generally good, with a well-finished surface and a sharp, precise tip. However, the rapid dulling of the bit detracts from its overall usability.

Cost vs. Value

At a higher price point, the Milwaukee Cobalt Drill Bit is an investment. Given its premium construction and thoughtful design features, one would expect it to offer superior performance and longevity. However, the rapid dulling and reduced effectiveness in hard metal applications make it difficult to justify the cost. For the price, I expected a bit that could handle multiple holes in hard metals without losing its edge so quickly.

Final Thoughts

The Milwaukee Cobalt Drill Bit has some strong points, particularly in its initial performance and versatility across different materials. The design features like the split point tip and the 3-Flat Secure-Grip shank are commendable and add to the bit’s overall usability. However, the rapid dulling and reduced effectiveness in hard metal applications are significant drawbacks.

If you are looking for a drill bit that can handle occasional use on hard metals and excel in softer materials, this bit might still be a good option. Its ease of use and initial performance are commendable, and it works well for DIY projects that don’t require extensive drilling in hard metals. However, for those who need a reliable, long-lasting bit for frequent use in hard metal applications, the Milwaukee Cobalt Drill Bit may not be the best choice.

In conclusion, I would recommend the Milwaukee Cobalt Drill Bit with some reservations. It’s a solid performer for occasional use and works well on softer materials, but its durability and edge retention in hard metal applications leave much to be desired. If you can justify the cost for its initial performance and versatility, it’s worth considering. Otherwise, you might want to explore other options that offer better longevity for hard metal drilling tasks.