$18.29
A) Drill Diameter 3.5mm
B) Overall length 70mm
C) Flute length 39mm
Point angle 135 degrees
Frequently Asked Questions
What materials can this cobalt drill bit cut?
Our cobalt drill bits handle stainless steel, cast iron, hardened steel, alloy steels, aluminum, copper, and more.
What speed should I use when drilling metal?
Use our Speeds & Feeds Calculator to set the correct RPM. Running too fast will overheat the bit; slower speeds preserve sharpness.
Can cobalt drill bits be resharpened?
Yes — cobalt drill bits can be resharpened, giving you long-term value.
How is cobalt different from standard HSS?
Cobalt (M35, 5%) withstands higher heat and stays sharper longer, making it ideal for harder metals compared to standard high-speed steel.
Do I need cutting paste when drilling metal?
We recommend TTP CUT-IT cutting paste for smoother drilling, cooler operation, and longer tool life.
What customers say
Average rating:
4.9 / 5 ·
Based on
154 reviews
- DIYMark (YouTube) — “TTP HARD outperformed leading US bits on tough metals.”
- Catus Maximus (YouTube) — “Impressed with the M35 cobalt set and CUT-IT paste.”
- Customer — “Clean holes in stainless; slower RPM + paste made the difference.”
Reviews reflect the TTP HARD cobalt drill bits range. Independently tested and certified for hardness by SGS Testing.
3.5mm cobalt M35 metal drill bits
Drill stainless steel and harder metals easily:
- Heavy Duty Cobalt Drill Bits
- Suitable for drilling harder metals including stainless steel
- Used by professionals and home improvement enthusiasts
- Can be resharpened
- Rockwell hardness C average of 66 certification
- Money Back Guarantee
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Click here for Metric drill bit sizes
3.5mm Drill Bit for Metal – Precision Hole-Making for M4 Clearance
The 3.5mm drill bit for metal is great for M4 clearance holes. Durable cobalt steel and a split point give fast, accurate results in any metal.
Extra Clearance for M4 Bolts
The 3.5mm drill bit for metal is the go-to size when an M4 bolt needs just a bit more clearance. It’s often used in fabrication, HVAC installations, and control panels where fasteners need smooth fitment. This size helps avoid binding and ensures bolts pass cleanly through multiple layers.
Moreover, its slightly larger profile gives added flexibility without compromising strength or control. It’s perfect for through-holes or non-threaded fastener mounting.
Built for Strength and Consistency
Made from M35 cobalt, this bit handles heat better than standard high-speed steel. The 135° split point makes for clean entries without skidding. Even when you’re drilling angled surfaces or curved pipes, it starts clean and stays straight.
This 3.5mm cobalt drill bit can cut through:
Stainless steel, including 304 and 316
Cast iron, copper, and brass
Mild and hardened steels
Structural alloy panels
Fiberglass and rigid plastic
Use Cutting Paste for Smooth Results
To protect your drill bit and improve cut quality, use TTP CUT-IT metal cutting paste. The lubricant reduces friction and extends tool life, especially useful when working on stainless or hardened steels.
Dial In the Right RPM
Not sure how fast to spin your drill? Visit our Speeds & Feeds Calculator and enter your material and bit size. This free tool gives accurate speed and feed settings in seconds.
TTP HARD Delivers Quality, Guaranteed
Whether you're working in a garage, shop, or out on site, the 3.5mm drill bit for metal gets the job done right. It’s trusted by tradesmen, engineers, and serious DIYers across the USA (read what they say).
With our no-risk money-back guarantee, you can buy with total confidence.
Additional information
| Weight | 0.18 lbs |
|---|
Prices : All Prices are United States (US) Dollar ($) Shipping : We ship from Michigan Warehouse across North America & Canada (Max cart weight 4.2lbs for Canada)