Category: Drills
How to Choose the Right Drill for CNC Machining
Drilling is one of the most-performed operations in any machine shop. Choosing right between solid carbide drills, indexable drills, and HSS-Co drills determines hole quality, cycle time, and cost-per-hole. Hooguu stocks drills from Sandvik, Walter, OSG, YG-1, Mitsubishi, and Iscar.
Decision Matrix by Diameter and Depth
- Diameter < 12mm → Solid carbide drill always wins (better hole quality)
- 12-25mm, depth ≤ 3×D → Indexable drill (lowest cost-per-hole)
- Diameter > 25mm → Indexable drill or specialty Spade drill
- Depth > 5×D → Solid carbide with through-coolant or gun drill
- Tolerance H8 or better → Solid carbide + reaming
Solid Carbide Drills
Sandvik CoroDrill 460, Walter A3782, OSG ADO series. Hole tolerance IT9-IT10 straight from the drill. Premium AlTiN coating extends life 3-5× over uncoated. Best for production drilling of repeating hole sizes.
Indexable Drills
Replaceable carbide inserts mean lower cost-per-hole and one body covers a diameter range. Hole tolerance IT12 typical, surface finish rougher. Sandvik CoroDrill 880, Iscar Chamdrill. Run 30-50% faster cutting speeds than solid carbide because chip evacuation is easier.
Material-Specific Selection
| Material | Drill Type | Coating |
|---|---|---|
| Mild steel | Solid carbide or indexable | TiAlN |
| Stainless 304/316 | Solid carbide w/ internal coolant | AlTiN |
| Cast iron | Solid carbide, no coolant needed | TiAlN |
| Aluminum | Solid carbide, polished flutes | Uncoated or DLC |
| Inconel/Titanium | Solid carbide w/ HP coolant | AlTiN nano |
| Hardened steel | Solid carbide micrograin | nACo |
Through-Coolant vs External Coolant
For depths over 4×D, through-coolant is mandatory. External coolant cannot reach the cutting edge in deep holes; chips re-cut and damage the drill. Modern HMC and HSK spindles deliver coolant at 70+ bar through the tool — pair with through-coolant drills for 200-400% tool life vs flood-only.
Speed and Feed Starting Points
- Steel 1045, 12mm carbide drill: 80-120 m/min, 0.20-0.30 mm/rev
- Aluminum 6061, 12mm carbide drill: 200-300 m/min, 0.30-0.40 mm/rev
- Stainless 304, 12mm carbide drill: 50-70 m/min, 0.15-0.20 mm/rev
Browse our drill catalog below. See also our complete indexable vs solid carbide comparison.
How to Choose the Right Drill for CNC Machining
Drilling is one of the most-performed operations in any machine shop. Choosing right between solid carbide drills, indexable drills, and HSS-Co drills determines hole quality, cycle time, and cost-per-hole. Hooguu stocks drills from Sandvik, Walter, OSG, YG-1, Mitsubishi, and Iscar.
Decision Matrix by Diameter and Depth
- Diameter < 12mm → Solid carbide drill always wins (better hole quality)
- 12-25mm, depth ≤ 3×D → Indexable drill (lowest cost-per-hole)
- Diameter > 25mm → Indexable drill or specialty Spade drill
- Depth > 5×D → Solid carbide with through-coolant or gun drill
- Tolerance H8 or better → Solid carbide + reaming
Solid Carbide Drills
Sandvik CoroDrill 460, Walter A3782, OSG ADO series. Hole tolerance IT9-IT10 straight from the drill. Premium AlTiN coating extends life 3-5× over uncoated. Best for production drilling of repeating hole sizes.
Indexable Drills
Replaceable carbide inserts mean lower cost-per-hole and one body covers a diameter range. Hole tolerance IT12 typical, surface finish rougher. Sandvik CoroDrill 880, Iscar Chamdrill. Run 30-50% faster cutting speeds than solid carbide because chip evacuation is easier.
Material-Specific Selection
| Material | Drill Type | Coating |
|---|---|---|
| Mild steel | Solid carbide or indexable | TiAlN |
| Stainless 304/316 | Solid carbide w/ internal coolant | AlTiN |
| Cast iron | Solid carbide, no coolant needed | TiAlN |
| Aluminum | Solid carbide, polished flutes | Uncoated or DLC |
| Inconel/Titanium | Solid carbide w/ HP coolant | AlTiN nano |
| Hardened steel | Solid carbide micrograin | nACo |
Through-Coolant vs External Coolant
For depths over 4×D, through-coolant is mandatory. External coolant cannot reach the cutting edge in deep holes; chips re-cut and damage the drill. Modern HMC and HSK spindles deliver coolant at 70+ bar through the tool — pair with through-coolant drills for 200-400% tool life vs flood-only.
Speed and Feed Starting Points
- Steel 1045, 12mm carbide drill: 80-120 m/min, 0.20-0.30 mm/rev
- Aluminum 6061, 12mm carbide drill: 200-300 m/min, 0.30-0.40 mm/rev
- Stainless 304, 12mm carbide drill: 50-70 m/min, 0.15-0.20 mm/rev
Browse our drill catalog below. See also our complete indexable vs solid carbide comparison.
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0.20 DIN 1899 Kyocera Hartner micro drill
Price on requestRequest a QuoteThe Kyocera M310206-84810-00-20 is a professional-grade carbide tool designed for drilling operations in steel, cast iron, and non-ferrous materials. Suitable for use on CNC lathes and machining centers with appropriate tool holders. Recommended for production environments where consistent surface finish and dimensional accuracy are critical. For optimal results, use with through-coolant or high-pressure coolant delivery. Available from Hooguu.com with worldwide shipping and competitive prici…
