Milwaukee 7/8" S&D Black Oxide Drill Bit

Drilling through metal, wood, or plastic can be a demanding task, and having a reliable drill bit is crucial. The Milwaukee 7/8" S&D Black Oxide Drill Bit, model 48-89-2750, is designed to offer durability and efficiency, making it a valuable addition to any toolbox.

Design and Build Quality

One of the first things that stand out about this drill bit is its robust construction. The black oxide coating provides corrosion resistance, which is essential for prolonged tool life, especially when working in various environments. This coating not only helps in resisting rust but also provides a smoother drilling experience by reducing friction.

The 3-Flat Secure-Grip shank is a thoughtful design feature. It ensures that the bit stays securely in the drill chuck, preventing any slipping or spinning that could compromise the precision of your work. This is particularly useful when you need to maintain accuracy, especially in demanding tasks.

Precision and Performance

The 135° split point tip is a notable feature of this drill bit. It allows for precise starting and significantly reduces the risk of walking. This is a crucial aspect, especially when you are working on materials that require exact hole placement. In my experience, the bit starts easily and maintains an accurate path, which is a testament to its design and craftsmanship.

The parabolic flute design is another highlight. This design aids in efficient chip clearance, preventing any clogging that could slow down your work. The flute length of 3 inches is adequate for most tasks, allowing for smooth and continuous drilling.

Versatility

The reduced shank diameter makes this bit compatible with 1/2" chucks, which adds to its versatility. Whether you are working with metal, wood, or plastic, this drill bit performs efficiently across different materials. I found it particularly useful when drilling through thin metal sheets and wood, where the step design allows for clean and precise holes.

Practical Use

In practical use, chucking the bit into my cordless drill was straightforward. The 3-flat shank ensured that the bit stayed securely in place, and I didn't experience any slipping. Drilling a 7/8” hole in thin metal was surprisingly easy. I marked the starting point with a center punch and then used the bit to start and drill the hole. The 135° split point tip really shone here, as it prevented the bit from wandering off the mark.

When drilling through sheet metal, it's crucial to watch the pressure you apply. Too much pressure can cause the flutes to snag, especially at the start of each step. However, once you get the hang of it, the bit performs admirably. I also drilled bolt holes in 1” angle iron, and the bit went through with minimal effort. The Rapid Strike tip is a definite advantage, making the drilling process smoother and quicker.

One of the added benefits of this bit is the ability to chamfer holes using the next diameter step. This feature allows for quick and easy deburring, which is often a time-consuming task. The chamfers produced were better than what I've achieved using a dedicated chamfering bit, making this drill bit a multifunctional tool.

Durability Concerns

Despite its impressive performance, durability remains a concern for some users. While my experience with the bit has been largely positive, there are reports of the bit dulling quickly when used on harder materials or breaking during the first use. This suggests that while the bit is excellent for light to medium tasks, it may not hold up as well under heavy-duty use.

Proper care and usage can mitigate some of these issues. Using the bit at a low speed and allowing it to do its job without applying excessive force can extend its life. This is a general rule for all drill bits, but it seems particularly pertinent for this model.

Room for Improvement

While the 3-flat shank design is effective, a hex shaft could have been an even better choice. A hex shaft would prevent any potential spinning in the chuck, especially when you’re really pushing the bit. This would add an extra layer of reliability and make the bit even more user-friendly.

Conclusion

The Milwaukee 7/8" S&D Black Oxide Drill Bit is a robust and efficient tool that excels in precision and ease of use. Its thoughtful design features, like the 135° split point tip and 3-flat shank, make it a reliable choice for various drilling tasks. However, its durability under heavy-duty use is a point of contention, and users should take care to use it within its capabilities to extend its lifespan.

For light to medium-duty tasks, this bit is an excellent addition to any toolbox. Its versatility across different materials and the added functionality of chamfering holes make it a multifunctional tool that can save time and effort in various projects.

Recommendation: I would recommend this drill bit for users who need a reliable and precise tool for light to medium-duty drilling tasks. Its design and performance features make it a valuable addition to any toolbox. However, if you frequently undertake heavy-duty drilling, you might want to consider a more robust option or be prepared to replace the bit more frequently.