Can HSS drill mild steel?

Yes. Good M2 HSS drill bits are suitable for mild steel when speed, pressure and cutting fluid are controlled.

Is cobalt necessary for mild steel?

Not always. Cobalt is useful for tougher or hotter conditions, but standard HSS can be more cost-effective for mild steel.

What coating is good for mild steel drilling?

Black oxide, TiN or other coatings can help depending on price and market positioning, but base steel and grinding quality still matter.

Why do HSS bits burn when drilling mild steel?

Usually speed is too high, pressure is too light, cutting fluid is missing or the bit is already dull.

HSS Drill Bit for Mild Steel

Mild steel is one of the most common drilling materials. It is also where many buyers overspend or underspecify.

Some customers ask for cobalt drill bits for every steel job. Others buy the cheapest HSS bit and wonder why it burns. The practical answer sits in the middle: a good HSS drill bit is often enough for mild steel, but the details matter.

Drill bit material selection guide comparing HSS cobalt carbide and TiN coated drill bits for different materials — For mild steel, the best value often comes from matching HSS grade, grinding and coating to the real user.

When HSS Is Enough

For ordinary mild steel plate, brackets, furniture hardware and general fabrication, M2 HSS is a sensible choice. It is tough, affordable and easier to use than more brittle premium materials.

If your customer uses hand drills, HSS can be more forgiving than carbide or high-cobalt bits. In many retail and contractor markets, that toughness matters more than laboratory tool life.

When to Move Up to Cobalt

Cobalt becomes more attractive when the drilling condition creates more heat: thicker steel, repeated holes, poor cooling or harder material. If the buyer drills stainless steel, then cobalt is usually a better conversation.

For mild steel only, cobalt is not automatically wrong, but it may be unnecessary for price-sensitive buyers. If the customer mainly wants general-purpose steel drilling, start with good HSS or HSS-G before jumping to M35.

Point Angle and Grinding

Many general HSS drills use a 118 degree point. For metal drilling, especially when walking is a problem, a split point or 135 degree design can help the bit start more accurately.

But do not treat point angle as a magic fix. Poor flute grinding, uneven cutting lips or bad heat treatment will still cause oversized holes, vibration or early dulling.

Coating Choices

Option	Use Case	Buyer Note
Bright finish	Low-cost general use	Good when price is the main factor.
Black oxide	General steel drilling	Better appearance and friction control.
TiN coating	Retail sets, longer wear claim	Useful, but coating quality must be stable.
HSS-G	Cleaner holes, better accuracy	Ground flute quality is the selling point.

Why HSS Bits Burn

If an HSS bit turns blue quickly in mild steel, the problem is often not only the bit. Common causes are high RPM, light pressure, no cutting fluid, workpiece movement or an already dull edge.

For buyer education, this matters. A better bit helps, but wrong use can destroy even a good bit. Packaging and product pages should include simple speed and lubrication guidance.

What Importers Should Ask Suppliers

What HSS grade is used?
Is the bit rolled or fully ground?
What hardness range is controlled after heat treatment?
What point angle is supplied?
Which coating options are available?
Can samples be tested in mild steel before bulk order?

For a broader comparison, read HSS vs cobalt drill bits and carbide vs HSS drill bits.