What is a 3-flute countersink?
A 3-flute countersink is a cone-shaped cutting tool with three cutting edges used to cut a conical recess (countersink) for flat-head and countersunk screws. It is the professional standard for CNC and production work: three flutes balance the cutting forces, so the tool runs true without chatter, cuts faster, and each flute wears less — typically lasting 3x longer than a single-flute countersink in the same material.
Why choose a 3-flute countersink?
| Feature | 3-Flute Countersink | Single-Flute Countersink |
|---|---|---|
| Cutting edges | 3 | 1 |
| Feed rate | Up to 3x faster | Standard |
| Chatter / vibration | Low, balanced cutting | Can chatter at high feed |
| Surface finish | Smoother, uniform cone | Good |
| Tool life | ~3x longer | Standard |
| Best for | CNC production, DIN 335 jobs | Hand tools, light work |
DIN 335 standard (Senker)
DIN 335 is the German standard for 3-flute countersinks (Senker). Lihao Technology manufactures DIN 335 3-flute countersinks on our own in-house precision grinders, giving angle tolerance of ±0.1° and repeatable geometry from batch to batch — a key advantage for customers who need consistent countersink depth and angle across large orders.
Available specifications
| Head Diameter (mm) | Shank Diameter (mm) | Angles | Material |
|---|---|---|---|
| 8 | 5 | 60° / 90° / 100° / 120° | HSS-E Cobalt (M42) |
| 10 | 6 | 60° / 90° / 100° / 120° | HSS-E Cobalt (M42) |
| 12 | 8 | 60° / 90° / 100° / 120° | HSS-E Cobalt (M42) |
| 16 | 8 | 60° / 90° / 100° / 120° | HSS-E Cobalt (M42) |
| 20 | 10 | 60° / 90° / 100° / 120° | HSS-E Cobalt (M42) |
| 25 | 12 | 60° / 90° / 100° / 120° | HSS-E Cobalt (M42) |
Frequently asked questions
What is a 3-flute countersink used for?
It cuts a conical seat for flat-head screws and rivets on CNC machines, drill presses and machining centers. The three-flute design gives faster feed, less chatter and longer tool life than single-flute tools.
3-flute or single-flute countersink — which should I choose?
For production runs, CNC work and stainless steel, choose 3-flute for speed, stability and life. For light manual work or very soft materials, single-flute is sufficient.
What does DIN 335 mean?
DIN 335 is the German industry standard for 3-flute countersinks (Senker) with a 60° cone angle series; it defines geometry, dimensions and tolerances for interchangeable tools.
Why is Lihao Technology 3-flute countersink more consistent?
We grind DIN 335 countersinks on our own in-house precision machines with ±0.1° angle tolerance, using German-imported M42 cobalt HSS bar stock, so every batch is repeatable — ideal for volume buyers.
