12 Steel Drill Bits Tested: The Cheapest Beat Cobalt

Drilling steel eats regular drill bits alive if you buy the wrong ones. Mild steel dulls a cheap bit fast, spring steel fights back even harder, and stainless steel work-hardens as you cut, which is exactly why cobalt bits marketed for metal work carry such a steep price premium, sometimes nearly triple the cost of a basic set.

A hands-on test of twelve twist drill bit brands settled the question of whether that premium buys anything, running every brand through half-inch mild steel, spring steel, and 3/8 inch stainless, plus a bonus test that involved drilling straight through a wrench. The winner was not the most expensive bit in the lineup, and it was not particularly close.

What the testing showed

The numbers below come from Project Farm, who tested twelve brands of twist drill bits through identical mild steel, spring steel, and stainless steel drilling tests. You can watch the full breakdown on the twist drill bit test. One clear overall winner was named in the video.

The cheapest bit in the test beat cobalt bits costing nearly triple

DeWalt, a black oxide 14-piece set priced at just $14.97, was the fastest of all twelve brands on the half-inch mild steel test at 47 seconds, showed no visible damage, and produced a very clean cut. It was also one of only three brands (with Craftsman and Bosch) able to cut through spring steel using the baseline amount of downward force, meaning it did not require extra pressure to overcome the material's hardness. The video's verdict: DeWalt was declared the overall winner, described as costing less and delivering more than the competition.

The most expensive bit still had a real edge on hard steel

Bosch, an M42 8 percent cobalt set at $39.99, the most expensive brand tested, finished a very close second on mild steel (51 seconds) but posted the smoothest finish of all twelve brands and claims a 10-times-longer lifespan than standard bits. The host's own recommendation: Bosch would be his pick specifically for a job involving a lot of hard steel like 304 stainless, despite being the priciest brand, because of its durability claim and finish quality.

Titanium-coated bits needed dramatically more force on spring steel

Several titanium-coated sets struggled where the top three (DeWalt, Craftsman, Bosch) did not. Bauer needed roughly double the downward force of the top performers to cut through spring steel (about 220 lb versus 111 lb). Warrior needed the test's original 15 lb weight doubled to 30 lb, over 200 lb of total downward force, and Metabo struggled badly even after adding extra force, described in the notes as "not making very much progress at all," with a visibly dulled cutting lip and chisel afterward.

Stainless steel speed did not track with mild steel speed

Masterforce, the second most expensive brand tested at $29.99, was a middling performer on mild steel (1 minute 41 seconds) but was the fastest of all twelve brands on 3/8 inch stainless steel at just 19 seconds, faster even than DeWalt (23 seconds) and Bosch (24 seconds). That is a useful reminder that a bit's performance on one material does not necessarily predict its performance on another.

How to read this for your own purchase

Cobalt content, titanium coating, and price all get marketed as proxies for "cuts steel better," and this test shows that proxy breaks down in practice.

If you drill mild steel occasionally around the shop, the test's own numbers make a strong case for DeWalt's cheap black oxide set: fastest overall, clean cut, and one of only three brands that did not need extra force on spring steel.

If you regularly drill hardened or stainless steel, Bosch's cobalt set earned its price premium on finish quality and the host's own explicit recommendation for hard-steel jobs, even though it was not the fastest bit in the test.

If stainless steel specifically is your main material, Masterforce's stainless result (19 seconds, fastest of all twelve) is the more relevant number than its middling mild-steel time.

Avoid assuming titanium coating alone solves the hard-material problem. Several titanium-coated bits in this test needed dramatically more force than the plain black oxide and cobalt bits that finished at the top.

It also helps to understand what actually differentiates a bit built for steel from a general-purpose bit, beyond the cobalt or titanium label on the packaging. Cobalt bits are alloyed with cobalt steel throughout the bit body, giving them genuine heat resistance that holds an edge longer under the friction of cutting hard metal, which is why Bosch's cobalt set kept the smoothest finish of the whole field even at a close second on speed. Titanium coating, by contrast, is typically just a surface treatment over standard high-speed steel, adding some initial hardness and reduced friction, but once that thin coating wears through, the bit underneath behaves like an uncoated bit again, which may explain why several titanium-coated sets in this test needed dramatically more force partway through the spring steel test. Knowing that distinction helps explain the pattern in the results, not just the raw numbers.

A few universal rules the data supports:

• Match the bit to the specific metal, not a general "for steel" label. Speed rankings shifted meaningfully between mild steel and stainless steel in this test.
• Downward force required is a real durability signal, not just a technique issue; several bits that struggled needed far more force than the top finishers to make the same cut.
• The cheapest bit is not automatically the weakest one. The overall winner of this entire test was also the second-cheapest brand.

Looking for more cutting tools tested the same hands-on way? Browse the rest of the blades, bits and abrasives tests for drill bit sets, saw blades, and sharpeners.