Best Drill Bits 2026: 14 Sets Tested on Mild Steel, Spring Steel, and AR500 Armor

Introduction

A high-quality set of drill bits can feel like a genuine investment. But does a $13 set perform just as well as one that costs $180? To answer that, we put 14 drill bit sets through a series of demanding tests: drilling through half-inch mild steel, spring steel, and finally AR500 armor plating. The results reveal which sets offer real value, which ones prioritize speed, and which ones hold up best under heavy use.

How We Tested

All drill bits were tested on a 1 horsepower drill press with a pulley wheel attached to the lever arms. For the mild steel test, 15 lb of weight on the pulley wheel produced close to 130 lb of downward force on the drill bit, with the RPM set to 600 for a 3/8 inch bit. Cutting oil was used to protect the bits during drilling.

The spring steel test increased the weight to 20 lb, delivering around 175 lb of force, with the RPM lowered to 340. The final test against AR500 armor plating used 25 lb of weight for roughly 220 lb of downward force at 250 RPM. Each drill bit was timed precisely, and performance loss was measured by repeating the mild steel and spring steel tests after the initial runs.

Kobalt Ware Drill Bits

The Kobalt Ware set costs $36 and includes 14 bits in sizes from 1/16 up to 1/2 inch. These bits are made of M42 cobalt with a precise 135° split point. They are designed to cut through tough metals such as stainless steel, cast iron, and high temperature alloys, while also handling softer materials like plastic and wood.

In the mild steel test, the Kobalt Ware finished in 19.65 seconds, moving into second place behind the DeWalt cobalt. On spring steel, it barely outperformed the DeWalt cobalt at 21.79 seconds, and it held up remarkably well, still looking nearly as good as new. When the mild steel test was repeated, the Kobalt Ware was actually faster at 18.68 seconds. On the second spring steel pass, it was less than 1% slower at 21.94 seconds, showing the least performance loss of any set tested.

The Kobalt Ware was also one of only four sets to successfully drill through AR500 armor plating, completing the job in 58.69 seconds, the fastest time of the four. It finished with the best average ranking of 1.6 across all tests, making it the standout value pick of the entire lineup.

Milwaukee Quad Edge Drill Bits

The Milwaukee set costs $65 for 15 bits, with sizes from 1/16 up to 3/8 inch. Unlike most other sets, the Milwaukee uses a quad edge tip design with cobalt alloy steel to handle hard metal. Milwaukee claims these bits offer 15 times the life of standard bits.

The Milwaukee made very easy work of the mild steel plate, finishing in 20.6 seconds. On spring steel, it moved into the lead with an impressive 17.65 seconds, the fastest time of that test. When the mild steel test was repeated, the Milwaukee was actually 19% faster at 17.24 seconds, suggesting a break-in period for the unique tip design. On the second spring steel pass, it continued to lead at 19.46 seconds.

The Milwaukee was the second set to defeat the AR500 armor plating, completing the job in 1 minute and 17 seconds. It finished with an average ranking of 2.4. The main downside is that the set does not include a half-inch twist drill, which the less expensive Kobalt Ware set does include.

Irwin M35 Cobalt Drill Bits

The Irwin set costs $130 and includes 29 bits in sizes from 1/16 up to 1/2 inch. These bits are made of M35 cobalt alloy steel with a 135° split point, designed specifically for hardened steel.

The Irwin was not the fastest through mild steel at 23.55 seconds, but it performed well on spring steel at 24.16 seconds. The Irwin held up really well throughout testing, still looking nearly as good as new after the spring steel passes. On the repeated mild steel test, it needed about 3 seconds longer at 27 seconds. On the second spring steel pass, it finished in around 28 seconds, still in pretty good condition.

The Irwin was the third set to defeat the AR500 armor plating, completing the job in just over a minute at 60.29 seconds, the second fastest time of the four successful sets. It finished with a third-place overall ranking. While more expensive than the top performers, the Irwin set offers a solid combination of durability and steady performance across all materials.

Viking Drill and Tool Drill Bits

The Viking Drill and Tool set costs $180, making it the most expensive set tested. It includes 25 bits in metric sizes from 1 to 13 mm, constructed of M42 cobalt steel with a 135° split point. The bits are made in the USA.

The Viking was not designed for speed, finishing the mild steel test in 32.85 seconds. On spring steel, it finished in 31.82 seconds, about 3 seconds slower than the Drill Hog. However, the Viking held up exceptionally well, looking nearly as good as new after each test. On the repeated mild steel test, it was actually faster at 31.82 seconds. On the second spring steel pass, it slowed by only 8% and finished in just under 35 seconds.

The Viking was the fourth and final set to defeat the AR500 armor plating, making steady progress throughout. It finished with an average ranking of 5.4. While not the fastest option, the Viking set is a very good and durable choice for those who prioritize longevity over speed.

Other Sets Tested

Several other sets were tested and showed notable results. The DeWalt 135° split point bits, priced at $13 for 14 bits, finished the mild steel test in 23.55 seconds but did not survive the second spring steel attempt. The Makita set at $19 for 14 bits was faster through mild steel at 20.76 seconds but also gave up during the second spring steel pass.

The DeWalt cobalt alloy steel bits at $29 for 14 bits were the fastest through mild steel at 16.36 seconds, thanks to their German-made pilot point design. However, they showed increasing wear and tear on subsequent passes. The GM Tools set at $40 for 29 bits finished mild steel in 20.55 seconds but experienced significant wear and tear. The Bosch M42 cobalt set at $40 for 14 bits suffered a bad chip during spring steel testing, which hurt its performance in later tests.

The Carbor set at $60 for 29 bits struggled after spring steel damage, taking close to 3 minutes on the second spring steel pass. The Highfire set at $63 for 29 bits failed to complete the repeated mild steel test and was skipped for the second spring steel pass. The Warrior set at $75 for 29 bits performed well initially at 19.51 seconds on mild steel but suffered significant battle damage and gave up just short of completing the second spring steel pass. The Drill America set at $94 for 29 bits held up reasonably well, finishing the repeated mild steel test in 21.89 seconds. The Drill Hog set at $140 for 29 bits was durable but slow, and it ran out of steam just before completing the AR500 test, coming less than a millimeter away from finishing.

Overall Buying Advice

When choosing a drill bit set, consider what matters most for your projects. If you want the best combination of speed, durability, and value, the Kobalt Ware set is the clear winner. It drilled fast through both mild and spring steel, showed the least performance loss of any set, and was the fastest to defeat the AR500 armor plating, all for less than $40.

If speed is your priority and you do not need a half-inch bit, the Milwaukee set is an excellent choice. It was the fastest through spring steel and remained the drill to beat in repeated tests, though it does experience faster performance loss compared to the Kobalt Ware.

For those who want a larger set with 29 pieces and are willing to pay more, the Irwin set offers steady, durable performance across all materials. It was the second fastest through the AR500 armor and held up very well throughout testing.

The Viking set is the most expensive option but delivers exceptional durability. It is not fast, but it held up nearly as good as new through every test and was one of only four sets to defeat the AR500 armor plating. If longevity matters more than speed, this is a strong contender.

Conclusion

The testing revealed that price does not always determine performance. The affordable Kobalt Ware set outperformed sets costing several times more, proving that a well-designed M42 cobalt bit with a precise split point can deliver exceptional results. The Milwaukee, Irwin, and Viking sets each offer their own strengths, whether that is raw speed, durability, or a comprehensive kit. For most users, the Kobalt Ware set represents the best overall value, combining fast drilling, excellent durability, and a price that is hard to beat.