Best Step Drill Bits Tested: 20 Brands Put Through Mild Steel, Stainless Steel, and AR500

Introduction

Step drill bits look similar on the shelf, but performance differences are dramatic. To find out which brands actually deliver, twenty step drill bits were purchased at prices ranging from about $7 for a budget option to over $120 for a premium Snap-On Blue Point, then tested through mild steel, stainless steel, and extremely hard AR500 armor plate.

The short version: the most expensive bit was nowhere near the best, and a $30 cobalt bit from Teemo turned out to be the standout all-around performer.

How the Test Worked

Every bit was run on a drill press with a weighted lever arm delivering a constant 54 pounds of downward force, set to 990 RPM, so each brand faced identical conditions. Testing covered three stages: drilling speed in mild steel, drilling speed and hole quality in stainless steel, and finally a torture test on AR500 armor plating with cutting oil and roughly 200 pounds of downward force.

Sizes tested ranged from 3/16 inch up to 7/8 inch. Notably, many of the strongest performers cost far less than the big-name premium bits, and several expensive brands underperformed badly.

Top Performers at a Glance

In the mild steel speed test, the CB brand was fastest at 4.17 seconds, with DeWalt second at 6.55 seconds and Teemo third at 7.53 seconds. In the medium hardness steel test, DeWalt posted the fastest complete 7/8 inch hole at 7.79 seconds, followed by Greenlee at 9.39 and Norseman at 10.17. In stainless steel, CB drilled the pilot hole in just 1.27 seconds, with DeWalt at 2.67 and Teemo at 3.18. On the AR500 armor plating test, Teemo was the only bit in the entire lineup to drill completely through.

Best Overall: DeWalt Step Drill Bit

DeWalt won a previous comparison and held its quality here. It cut the mild steel pilot hole in 6.55 seconds, was second fastest in stainless steel at 2.67 seconds with the largest hole at the time (0.64 inch), and blasted through medium hardness steel with the fastest overall completion time of 7.79 seconds. Across all categories it averaged a fourth-place finish, the best overall ranking of the twenty bits.

The trade-off is durability. On AR500 armor plating the DeWalt lasted only about two seconds, leaving just 1.67 mm of progress and visible damage to the chisel and flute edges. It also is not marketed as M35 cobalt. If your work involves hard steel, look elsewhere; for everyday mild steel and general trade use, it is excellent.

Best for Durability: Teemo M35 Cobalt Step Drill Bit

The Teemo M35 Cobalt step drill bit, priced at $30, was nearly as fast as the DeWalt in every speed test, cutting the mild steel pilot hole in 7.53 seconds and stainless steel in 3.18 seconds while leaving an impressively large 0.736 inch hole. Its double spiral flute design cleared swarf efficiently, and the bit still looked close to new after the stainless steel round.

Where it truly separated from the field was the AR500 armor plating test. Teemo was the only bit of all twenty to drill completely through the plate, stopping around the 18-second mark only after penetration, with minimal wear. Considering the $30 price and the performance, it is the easiest recommendation in the lineup.

Best Value Speed: CB Step Drill Bit

At $27, the CB brand high-speed steel bit with black oxide M2 material and a dual flute design was the outright speed champion. It drilled the mild steel pilot hole in 4.17 seconds, roughly twice as fast as the next competitor, and shredded stainless steel in just 1.27 seconds with the fastest pilot hole of the entire test.

The aggressive flute geometry is also its weakness: the spiral flutes pull the bit into the cut so quickly that it stalled and jammed in medium hardness steel at 0.44 inch and in the AR500 test, requiring repeated release. It finished with the least AR500 progress at 5.86 mm. If you mostly drill mild steel and stainless, it is a fantastic value; for hard steel, it is the wrong tool.

Best for Hard Steel Versatility: Sharp Tool Step Drill Bit

The $18 Sharp Tool bit, made of M2 high-speed steel with a wear-resistant coating, was a consistent middle-to-top performer. It led the mild steel test early at just over 11 seconds, cut a stainless steel pilot hole in 6.65 seconds, and on the brutal AR500 test made 10.81 mm of progress, the third-best result in the entire lineup.

For a bit at this price, that combination of speed and toughness is remarkable, and it can start drilling without a pilot hole.

Most Improved: Klein Tools Step Drill Bit

Klein Tools has improved dramatically. Four years ago its straight-flute bit was one of the slowest, taking 34 seconds in mild steel; this time it finished in just over 12 seconds. In medium hardness steel it completed the full hole in 11.15 seconds, third best, and in stainless steel it drilled a 3.55 second pilot hole with the largest hole of the round at 0.77 inch.

It also performed well on AR500 with 10.21 mm of progress, better than most. The straight flute design helps it avoid jamming as it steps up to larger hole sizes. At $34, it earns a podium-level overall finish.

Brands That Disappointed

Several expensive bits fell well short of expectations. The $123 Snap-On Blue Point drilled a mild steel pilot hole in 15.48 seconds, slower than bits a fraction of its price, and managed only 5.3 mm on AR500, about half the progress of the $18 Sharp Tool. The $100 Mac Tools bit was one of the slowest in mild steel at 24 seconds and could not cut stainless steel at all.

Milwaukee went from a 10-second mild steel time years ago to over 30 seconds here, and managed only 2.8 mm on AR500 with significant damage. The Freud Diablo from Switzerland, $50 per bit, slowed to over 30 seconds in mild steel and could not handle stainless steel. Greenlee is not advertised for hard steel and lasted about two seconds on AR500. Also underwhelming were the $33 EAS Ark Obsidian (25.82 seconds in mild steel), the $53 Tulem (12.34 seconds), the $30 Wanu (12.23 seconds, though it did place second on AR500), the Hercules, Ox Mule, Pitt, Nico, Irwin, and Norseman, which were acceptable but outperformed by cheaper rivals.

Overall Buying Advice

Skip the very expensive step bits that do not perform to their price, and skip the very cheapest ones too. Match the bit to the material: for everyday mild steel and stainless work, DeWalt and CB are superb, and for maximum toughness across hard steels, the Teemo M35 Cobalt offers the best combination of speed, durability, and value at $30.

Conclusion

Twenty step drill bits, one clear pattern: price is a poor predictor of performance. The Teemo M35 Cobalt bit delivered near the fastest times in every test and was the only bit to drill completely through AR500 armor plating, while several premium brands costing two to four times more finished near the bottom. For most buyers, a $30 cobalt bit is the smart money.