9 Best 6.8 Mm Drill Bit | Skip the Cheap 6.8 Mm Sets That Snap

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If you need to drill a precise 6.8 mm hole in metal, the real question isn’t which bit looks shiny — it’s which one will cut cleanly without wandering or snapping mid-project. A 6.8 mm bit is the exact pilot size for an M8 threaded hole, so this choice directly decides whether your tap runs true or your workpiece gets ruined.

I’m Min — the founder and writer behind Gadgets Feed. This guide is built by comparing the manufacturers’ published specifications and the patterns across verified customer reviews, so you get each pick’s real strengths and trade-offs instead of marketing spin.

From cheap multi-packs to pro-grade cobalt, here are the 6.8 mm drill bit options that actually hold up, with honest notes on which materials each one handles best.

Our Picks at a Glance

uxcell M8 x 1.25 Spiral Point Thread Tap and 6.8mm Drill Bit Set
Best Overalluxcell M8 x 1.25 Spiral Point Thread Tap and 6.8mm Drill Bit Set4.7★236 ratingsThe rare set that gives you the exact 6.8 mm pilot bit and the M8 tap that fits it.Check Price on Amazon
Chicago-Latrobe 550 Heavy-Duty Cobalt Jobber Drill Bit, 6.8 mm, Pack of 12
Precision PickChicago-Latrobe 550 Heavy-Duty Cobalt Jobber Drill Bit, 6.8 mm, Pack of 124.9★79 ratingsThe pro’s choice when a ruined hole costs far more than the bit itself.Check Price on Amazon
HARFINGTON 10pcs M35 Cobalt Twist Drill Bit 6.8mm
Top PerformerHARFINGTON 10pcs M35 Cobalt Twist Drill Bit 6.8mm4.6★22 ratingsCobalt steel that chews through hard metals without losing its edge. For drilling stainless steel, alloy steel, and cast iron, the M35 cobalt construction here is the key upgrade over standard HSS.Check Price on Amazon

How To Choose The Best 6.8 mm Drill Bit

Your 6.8 mm bit must match the material you drill, or it will dull fast. A bit that glides through aluminum can dull instantly on hardened steel. Match the steel grade to your workpiece, and you save both time and money.

Match the steel grade to the job

Standard high-speed steel (HSS) handles soft metals, aluminum, and wood with ease. If you’re drilling stainless steel or other hard metals, step up to cobalt steel — the added cobalt keeps the cutting edge from overheating. For the toughest jobs on hardened steel, carbide is the answer, though you’ll need a stiff drill press setup.

Understand the point angle

The point angle is the sharp tip that starts the hole. A 118° split point is the general-purpose standard for soft metals and wood. A 135° split point is the better choice for hard metals because it puts less stress on the bit and resists walking across the surface when you start.

Count the cost of breakage

Thin 6.8 mm bits snap when you apply too much pressure or drill too fast. That’s why multi-packs are practical — a 12-pack means one broken bit doesn’t stall your project. If you’re drilling just a few holes, a single high-quality bit is the smarter buy.

Quick Comparison

Model Best For Material Point Angle Count Amazon
uxcell Tap + Bit Set★ Best Overall M8 tapping jobs Cobalt HSS 118° 2 Amazon
Chicago-Latrobe CobaltPrecision Pick Professional precision Cobalt 12 Amazon
HARFINGTON M35 CobaltTop Performer Hard metal drilling M35 Cobalt 135° 10 Amazon
kwb Roll-Forged HSS General metal drilling HSS 118° 1 Amazon
uxcell 12pcs Jobber Spare bits for volume M2 HSS 135° 12 Amazon
PATIKIL M2 12 Pack Multi-material drilling M2 HSS 118° 12 Amazon
uxcell 10pcs HSS 4341 Budget value packs HSS 4341 135° 10 Amazon
PATIKIL M35 Cobalt Stainless steel work M35 Cobalt 135° 10 Amazon
WKSTOOL Solid Carbide Hardened steel, CNC Solid Carbide 118° 1 Amazon

In-Depth Reviews

★ Best Overall

1. uxcell M8 x 1.25 Spiral Point Thread Tap and 6.8mm Drill Bit Set

Our pick — over 4.5★ from 200+ verified ratings; the strongest balance of quality and price.

Tap + Bit ComboCobalt HSS

The rare set that gives you the exact 6.8 mm pilot bit and the M8 tap that fits it.

This is the answer for anyone threading M8 holes — the 6.8 mm bit is the precise pilot drill for an M8 x 1.25 tap, and this set pairs them together so you never mismatch sizes. The tap uses a spiral point design that pushes chips downward, which keeps the threads clean as you cut through aluminum, stainless steel, bronze, and hard plastics.

The bit itself is cobalt high-speed steel rated at HRC65-66 hardness, so it holds up on jobs where a plain steel bit would dull fast. Buyers report using it on an aluminum heatsink for an amplifier and finding that it “worked great,” though one honest note was uncertainty about how it would handle steel. The tip is a 118° split point, which is the general-purpose standard for clean starts in softer materials.

You’ll need a separate tap handle to drive the tap — that’s a small extra cost to factor in. The kit includes just two pieces: one bit and one tap. For a quick, correct M8 threading job on non-hardened metals, this pairing saves you the headache of hunting for matching parts.

What Wins People Over

  • Functionality earns the top praise — the bit and tap work together as intended
  • Quality is the second most-discussed positive, with owners calling it good quality
  • Titanium plating resists corrosion and wear

Who Should Think Twice

  • Not built for hardened steel — owners admit uncertainty there
  • Only two pieces, so no spares if the bit breaks
  • Tap handle not included

Reach for it if: you’re doing M8 threading on aluminum or soft metals and want a matched bit-and-tap pair.

Look elsewhere if: you need a bit for hardened steel or want spare bits for repeated jobs.

Precision Pick

2. Chicago-Latrobe 550 Heavy-Duty Cobalt Jobber Drill Bit, 6.8 mm, Pack of 12

Professional GradeCobalt Steel

The pro’s choice when a ruined hole costs far more than the bit itself.

When the stakes are high — gunsmithing, tapping barrels, or receivers — accuracy is everything, and this 12-pack of cobalt jobber bits delivers the kind of reliability that mistake-free work demands. Owners note these bits are true, stay sharp, and are well matched to the corresponding tap. One gunsmith reports drilling dozens of holes in mild steel with a single bit that remained sharp.

Quality is what buyers praise most here, and the consensus is that these “cut beautifully” — outperforming more expensive fancy cobalt bits in direct comparison. Each bit weighs in at 2.4 ounces for the pack, and the straight shank design fits standard chucks. The brand carries decades of reputation, and the build shows it.

The honest trade-off is the price — this is the premium tier of 6.8 mm bits, and you’re paying for professional-grade consistency. One owner did break a small bit, but chalked it up to user error. If you’re a hobbyist drilling a couple of holes a year, this is overkill; if your work can’t tolerate a wandering or snapping bit, this is the insurance worth buying.

Pro-grade truth: These outperform many fancier cobalt bits in side-by-side use, and the 12-pack cushions any breakage. The investment only makes sense if your work demands it.

For the pro: gunsmithing, precision metalwork, or any job where a bad hole means starting over.

skip it if: you’re a weekend DIYer — the premium cost won’t pay off for occasional drilling.

Top Performer

3. HARFINGTON 10pcs M35 Cobalt Twist Drill Bit 6.8mm

M35 Cobalt135° Split Point

Cobalt steel that chews through hard metals without losing its edge.

For drilling stainless steel, alloy steel, and cast iron, the M35 cobalt construction here is the key upgrade over standard HSS. Cobalt added to the steel boosts hardness and thermal stability, so the bit keeps cutting even when friction heats things up. The 135° split point starts cleanly without walking across the workpiece — a real advantage on hardened surfaces.

The fully ground spiral groove flushes debris out fast, reducing friction and heat while drilling. With a working length of 57mm and total length of 109mm, these are jobber-length bits that fit standard chucks. One owner used them as an exact replacement matching the length of the original in a drill index, which matters for keeping your set organized.

There’s a real-world caution here: this size snapped on one owner during first use, though the same owner noted the 10-pack meant the project wasn’t delayed. Buyers sum it up: “drilled like butter” on one job. These bits are not for glass, tile, wall, or stone — keep them to metal and wood.

Hard-metal hero: The cobalt content and 135° split point make this the go-to for stainless and alloy steel. The 10-pack cushions breakage, which is realistic at this size.

Best for: anyone regularly drilling stainless steel or cast iron with a drill press.

Not for: masonry or tile — and be gentle with feed pressure on the first hole.

Stainless Specialist

4. PATIKIL 6.8mm Drill Bit M35 Cobalt 5% High-Speed Steel 10 Pack

M35 Cobalt 5%135° Split Point

Purpose-built for stainless steel, where lesser bits give up fast.

This 10-pack uses M35 high-speed steel with 4.5% to 5.5% cobalt content — the spec that makes it specifically suited for stainless steel and other high-hardness materials like carbon steel and iron. The 135° split point tip is what helps it start cleanly without wandering, which owners confirm: the bit “cuts through heavy steel” and easily handles aluminum window frames. The gold finish adds corrosion resistance to extend its life.

The flute length is 69mm with a 108mm overall length, and the straight shank works in standard chucks. Quality is the most-praised aspect, with functionality and drilling performance close behind — the consensus is a well-made, sharp bit that holds up. One owner even used it to remove a broken lug nut, working fast and as expected.

For best results, position the bit at 90° to the workpiece and use cutting fluid to reduce heat. On thick material, drill in multiple passes to prevent overheating or breakage. A few owners mention these shine in a drill press at low speed with firm, steady pressure rather than freehand in a hand drill.

Praised For

  • Quality leads the positive feedback — sharp and durable out of the pack
  • Drills stainless steel and heavy steel without issue
  • Good value for the 10-pack count

Consider Before Buying

  • Harder materials demand slow speed and cutting fluid
  • Freehand drilling in a hand drill is more likely to cause issues

Reach for this if: stainless steel is your main material and you want a 10-pack that won’t quit.

Look elsewhere if: you only drill wood or soft plastic — standard HSS is cheaper for that.

Best Value

5. uxcell 12pcs Jobber Drill Bits 6.8mm Black Nitride & Gold Titanium

M2 HSS12-Pack

Twelve sharp, coated bits for the price of two premium ones — a spare’s dream.

The M2 high-speed steel here (rated HRC64-66) gives these bits excellent heat resistance and hardness, and the dual black nitride and gold titanium coating helps them stay corrosion-resistant while drilling smoother. The 135° split point reduces walking on the work surface. With a cutting edge length of 69mm and overall length of 109mm, these are proper jobber bits, not stubby shortcuts.

This 12-pack is the answer when you drill multiple holes in the same size and need replacements ready for breakage — one owner specifically praised having spares on hand. The recommended speed is 100-800 rpm, and for holes larger than 6mm, the guidance is to start with a 3.2mm-4mm pilot bit first. These bits handle stainless steel, cast iron, aluminum, copper, wood, and plastic.

The catch is consistency: owners note that “some of them aren’t sharpened properly,” so a couple of bits in the pack might underperform. That’s the trade-off of a budget 12-pack. Most bits arrive sharp and hold their edge, but you’re gambling slightly on QC. If you need guaranteed sharpness for a critical single hole, a premium single bit is safer.

Volume play: A 12-pack means you stop worrying about breakage and just drill. The risk is a dud bit or two in the batch.

Best for: high-volume drilling where spares matter more than perfection.

pass on it if: you need one guaranteed-sharp bit for a critical job right now.

Budget Champion

6. uxcell 10pcs Straight Shank Twist Drill Bits 6.8mm HSS 4341

HSS 434110-Pack

A crowd-pleasing 10-pack that drills through sheet metal without draining your wallet.

With the highest review volume in this roundup, these HSS 4341 bits are the value pick that thousands of owners have put to work. Quality is the top praised aspect, and the consensus is that they’re sharp, effective, and drill through metal as advertised. One buyer drilled sheet metal and C channel effectively, noting the value was excellent at this price point.

The gold titanium and black nitride dual coating helps the bits apply lubricant better for smoother drilling, and the straight round shank clamps tightly without slipping. The cutting edge length is 57mm with a total of 108mm, and the 135° split point starts holes cleanly. These work on stainless steel, aluminum, iron, copper, brass, wood, and plastic.

The honest weakness is durability — multiple owners mention they break easily. Size also gets mixed feedback. So treat these as workhorse replaceables rather than heirloom tools. One owner flagged a wobble in a single bit out of the pack; the rest cut perfectly. If you’re drilling a few holes per project and don’t want to cry over a snapped bit, this 10-pack is the pragmatic call.

What The Crowd Likes

  • Quality leads the praise — sharp and effective out of the pack
  • Drill performance is a close second for most owners
  • 10 bits for the price of one premium bit

Where It Falls Short

  • Durability is the recurring gripe — handle with care
  • Occasional out-of-true bit with a wobble

Reach for this if: you want maximum bits per dollar for light metal and wood jobs.

Think twice if: you’re drilling heavy stainless daily — you’ll burn through these.

Multi-Material Pick

7. PATIKIL 6.8mm Drill Bit M2 High-Speed Steel 118° 12 Pack

M2 HSS118° Split Point

A versatile twelve-pack that handles aluminum dashboards and stainless plate alike.

The M2 high-speed steel here delivers good wear and heat resistance for general-strength drilling, and the gold finish adds corrosion protection. The 118° split point tip is the classic general-purpose angle, so this pack is comfortable across stainless steel, iron, aluminum, copper, plastics, and wood. Owners have put these to work drilling toggle switch holes in an aluminum dashboard, finding them precise and effective in softer materials.

Quality is the most-praised aspect, with performance a close second — the consensus is these “work great” for their intended applications. The flute length is 70mm with a 108mm overall length and a round shank for standard chucks. One owner drilled 12 holes in 316 stainless steel with a single bit in a drill press at lowest speed with lubricating oil and reported no binding or grabbing.

The guidance from the maker is worth following: position the bit at 90° to the workpiece, use a guide hole for large holes, and go with cutting fluid on harder metals. With 12 bits in the pack, you have the spares to handle breakage without pausing. For a do-everything 12-pack that won’t let you down on common metals, this is a strong middle option.

All-rounder: The 118° point and M2 steel make this the safe bet for mixed-material jobs. The 12-pack count makes breakage a non-issue.

Best for: the DIYer who needs one pack that handles aluminum, steel, and wood.

Not for: professionals drilling hard metals all day — spring for cobalt.

CNC Weapon

8. WKSTOOL 6.8mm Micro Solid Carbide Drill Bit TiAlN Coated

Solid CarbideTiAlN Coated

The bit that chews through hardened steel where standard drills give up and snap.

When standard HSS or even cobalt bits fail on hardened steel, this solid carbide bit is the nuclear option. Made from solid micro carbide (tungsten steel at HRC55) with a high-quality TiAlN coating, it’s designed for the toughest cutting applications. One owner reports it “cut through hardened steel like butter,” while another found it survived on stainless steel square tube where DeWalt, Bosch, and Lennox bits had failed — a direct head-to-head that speaks volumes.

This is a machine bit, not a hand-drill bit. Owners are emphatic: use it in a drill press or mill only, clamp the workpiece down, keep travel minimal, and use cutting fluid. With a 30mm flute length and 60mm total length, it’s short and stiff — exactly what you want for precision. The 118° point and a T.I.R. maximum of 10um (0.01mm) mean extremely low runout for accurate holes.

The honest limits: it dulls fast in a hand drill per one owner, and shipping can be slow. It’s also a single bit, so there are no spares. For CNC lathes, EDM presses, and chamfering applications, this is the specialist’s pick.

Specialist tool: This bit excels on hardened steel and stainless, but it needs a rigid machine setup and patience. The single-bit format and slow shipping are the trade-offs.

For the machinist: anyone with a drill press or mill working on hardened or heat-treated steel.

Avoid if: you only have a hand drill — this bit needs rigid control to perform.

Single-Bit Utility

9. kwb 6.8mm Roll-Forged HSS Metal Drill Bit with 118° Point Angle

DIN 338Single Bit

A single, roll-forged DIN 338 bit for exact M8 pilot holes in steel and cast iron.

If you need exactly one 6.8 mm bit for a single project, this kwb bit is the clean, standards-compliant choice. It conforms to DIN 338 standards with a Type N design and a 118° point angle, and the roll-forged HSS construction uses heated metal rods rolled into a spiral shape for efficient chip removal. The right-hand cut cylindrical design is ideal for an M8 threaded hole.

Versatility is the selling point here: it’s suitable for alloyed and unalloyed steel, cast iron, non-ferrous metals, and hard plastics. The bluish-black color you see is the standard finish from the manufacturing process. German and French owners generally praised the quality — one called it “very good quality, it’s an Einhell product.”

The honest caution is that one owner tested it in two separate pillar drills and reported wobble and curvature, a quality-control miss that stands out against the otherwise positive feedback. It’s a single bit with no spares, so if you get a good one, you’re set; if you get a dud, you’re out. For a straightforward single-hole job in mild steel, this is a reasonable pick, but the multi-packs above give you more margin for the same money.

Standalone buy: A solid DIN 338 bit for general metal drilling, but the single-bit format and occasional QC wobble make the 10- and 12-packs better value.

Reach for it if: you need one reliable 6.8 mm bit for a specific steel project.

Think twice if: you’d rather have spares on hand — the multi-packs give more safety.

Understanding the Specs

Steel Grade: HSS vs. Cobalt vs. Carbide

Standard high-speed steel (HSS) is the everyday workhorse — good for aluminum, wood, and soft steel. Cobalt steel (like M35) adds 5% cobalt for heat resistance, making it the right pick for stainless steel. Solid carbide is the hardest of all, capable of hardened steel, but it’s brittle and needs a rigid drill press.

Point Angle: 118° vs. 135°

The point angle is the sharp tip that starts the hole. A 118° split point is the general-purpose standard for soft metals and wood — easy starts, less stress. A 135° split point is built for hard metals, reducing walking across the surface and putting less pressure on the bit as it cuts. Match the angle to your hardest material.

FAQ

What is a 6.8 mm drill bit used for?
A 6.8 mm bit is the standard pilot hole size for an M8 threaded hole. You drill the 6.8 mm hole first, then use an M8 tap to cut the threads. It’s also used for general metal drilling in stainless steel, aluminum, and other materials when you need a precise hole of that exact diameter.
Will a 6.8 mm bit fit in my standard drill chuck?
Yes. Almost all 6.8 mm bits have a straight shank of the same 6.8 mm diameter, which fits standard 3/8-inch and 1/2-inch drill chucks. The shank design is universal for straight-shank jobber bits, so you can use them in hand drills, drill presses, and bench drills.
What is the difference between M2 and M35 cobalt steel?
M2 is a standard high-speed steel that’s hard and wear-resistant, suitable for most metals. M35 is high-speed steel with about 5% cobalt added, which gives it better heat resistance and hardness for drilling stainless steel and other tough materials. For hard metals, choose M35; for general use, M2 is sufficient and cheaper.
Can I drill hardened steel with a 6.8 mm HSS bit?
Standard HSS bits will struggle or dull quickly on hardened or heat-treated steel. For hardened steel, you need a cobalt (M35) bit at minimum, and for the hardest jobs, a solid carbide bit in a rigid drill press. Standard HSS is fine for mild steel, aluminum, and softer materials.
Should I use cutting fluid when drilling with a 6.8 mm bit?
Yes, cutting fluid or oil reduces friction and heat, which extends the bit’s life and produces cleaner holes. On harder materials like stainless steel, cutting fluid is essential to prevent overheating and breakage. On aluminum, a light lubricant helps prevent the material from sticking to the bit.
How fast should I run my drill with a 6.8 mm bit?
For a 6.8 mm bit, a slower speed is generally better, especially in metal. The larger the diameter, the slower the speed required. A recommended range for these bits is around 100 to 800 rpm. On harder materials, use lower spindle speed and feed rate to avoid overheating.
Why do my 6.8 mm drill bits keep breaking?
Breakage at this thin diameter usually comes from too much downward pressure, drilling too fast, or drilling without cutting fluid. Thick materials should be drilled in multiple passes to prevent overheating. Starting with a smaller pilot bit for holes over 6mm also reduces stress on the 6.8 mm bit.
What is a split point tip and why does it matter?
A split point tip is a modified drill point that has an extra cutting edge at the center. It helps the bit start a hole without walking or wandering across the workpiece surface. This is especially useful on hard metals and when you need precise hole placement without a center punch.
Is a 12-pack of 6.8 mm bits worth buying?
If you drill multiple 6.8 mm holes per project, yes. Thin bits break, and having spares means you never stop mid-project. If you only drill one or two holes occasionally, a single premium bit is a smarter buy than a 12-pack where some bits may sit unused.

Final Thoughts: The Verdict

For most buyers, the 6.8 mm drill bit winner is the uxcell M8 Tap + Bit Set because it pairs the exact pilot bit with the matching M8 tap, giving you a complete threading solution in one purchase. If you’re drilling stainless steel regularly, grab the PATIKIL M35 Cobalt 10-pack — the 5% cobalt content is built for hard metals. And for hardened steel or CNC work, the WKSTOOL solid carbide bit is the one to reach for, provided you have a rigid drill press.

How We Picked

We do not accept paid placement. Every pick is matched to a real buyer and a real use-case; we do not hands-on test units.

Sources & Methodology

Specifications: manufacturer listings and product documentation. Review insights: verified customer reviews, as of August 2026. Pricing: not shown on this page (it changes often); check the current price via the retailer link.

As an Amazon Associate, Gadgets Feed earns from qualifying purchases. This does not affect which products we feature.

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