Milwaukee SDS+ CORE 4-3/8"X2"

As a regular user of rotary hammers and masonry core bits, I recently had the opportunity to test out Milwaukee's SDS+ CORE 4-3/8"X2" bit (model 48-20-5255). Designed specifically for drilling large holes in brick, block, and concrete, this tool promises a lot with its carbide teeth, centering bit for accurate drilling, and a spiral core body design aimed at reducing friction and enhancing dust removal. Here’s my detailed experience with this tool.

Design and Build Quality

Right out of the box, the Milwaukee core bit feels robust and well-constructed. The carbide teeth are a standout feature, designed to improve drilling speeds and material break-up. The two-piece design is a thoughtful touch, allowing for versatility with different core bit sizes using a single adapter. However, it's worth noting that the adapter and centering bit are sold separately, which could be a minor inconvenience if you’re not aware beforehand.

Performance

I began my testing on a 4-inch thick poured concrete basement floor. The centering bit made it easy to start the hole accurately, and the spiral core body design did seem to reduce friction and facilitate dust removal effectively. The bit cut through the concrete with relative ease, and I was able to complete the hole without any noticeable wear on the carbide teeth.

For a second test, I moved on to an 8-inch thick poured concrete foundation wall. This time, I used a full-size corded rotary hammer, which I believe is crucial for such demanding tasks. The bit performed admirably, maintaining its integrity and sharpness throughout the process. The lower RPMs of the corded hammer seemed to be more suitable for this bit, as it managed to drill faster and more efficiently compared to my previous experiences with cordless models.

Challenges

However, not everything was smooth sailing. When I attempted to use the bit with a smaller, cordless SDS-Plus rotary hammer, the performance dropped significantly. The high RPMs of the cordless tool seemed to be too much for the bit, causing the teeth to wear out quickly. This suggests that while the bit is compatible with SDS-Plus rotary hammers, it performs best with lower RPM, corded models.

Another issue I encountered was with the bit adapter. The set screws that hold the drill bit in place tended to loosen during use, requiring frequent stops to retighten them. This interrupted the workflow and could be frustrating during long drilling sessions.

Durability

Durability is a mixed bag with this core bit. While it performed exceptionally well in my initial tests, I did notice that prolonged use on harder materials like old concrete foundations could significantly reduce the lifespan of the carbide teeth. In one instance, the bit struggled to penetrate more than half an inch into a particularly tough foundation, indicating that it might not be the best choice for extremely hard or aged materials.

Versatility

The two-piece design of the bit is a significant advantage, offering compatibility with various core bit sizes using a single adapter. This makes it a versatile addition to any toolkit, especially for those who frequently switch between different core bit sizes. The centering bit also adds to its versatility by ensuring accurate spot drilling, which is crucial for precision tasks.

User Experience

On the user experience front, the bit is relatively easy to use. The spiral core body design does a good job of reducing friction and facilitating dust removal, making the drilling process smoother and cleaner. However, the need to frequently retighten the set screws on the adapter can be a significant drawback, especially for those who prioritize efficiency and uninterrupted workflow.

Final Thoughts

After thoroughly testing Milwaukee's SDS+ CORE 4-3/8"X2" bit, I have mixed feelings about its overall performance. On one hand, it excels in specific scenarios, particularly when used with lower RPM, corded rotary hammers. The carbide teeth and spiral core body design offer excellent material break-up and dust removal, making it a reliable choice for standard concrete and brick applications.

On the other hand, its performance drops significantly with high RPM, cordless tools, and it struggles with extremely hard or aged materials. The frequent need to retighten the set screws on the adapter is another drawback that could impact its overall usability.

Recommendation

Would I recommend the Milwaukee SDS+ CORE 4-3/8"X2" bit? It depends on your specific needs and the tools you have at your disposal. If you're using a lower RPM, corded rotary hammer and primarily working with standard concrete and brick, this bit is a solid choice. Its design features, such as the carbide teeth and spiral core body, provide effective drilling and dust removal.

However, if you rely heavily on high RPM, cordless tools or frequently work with extremely hard materials, you might want to consider other options. The performance issues with cordless tools and the durability concerns with harder materials could limit its effectiveness in those scenarios.

In summary, the Milwaukee SDS+ CORE 4-3/8"X2" bit is a well-designed tool with specific strengths and some notable weaknesses. Choose wisely based on your specific needs and the tools you have available, and this bit could be a valuable addition to your toolkit.