After 18 months of production testing on 304 and 316 stainless (over 14,000 holes), the Amony ICF Series internal-coolant drills consistently deliver the longest tool life, best hole quality and lowest cost per hole.
Dual helical internal coolant channels → direct edge cooling, eliminates work-hardening zone
Sub-micron grain carbide + AlCrN coating → 3× tool life vs non-coolant carbide
3×D short rigid body + reinforced DIN shank → zero deflection even at 0.25 mm/rev feed
Diameters 2.4–20 mm in 0.1 mm steps → perfect for production
Real data: 316 SS valve body, 8 mm hole → 1,240 holes per edge (vs 380 with external flood)
Stainless Steel 304/316 Drilling Challenges – Real Causes
ICF Series vs UPX vs HSS – Side-by-Side Data
Exact Parameters That Gave Us 3× Tool Life
Size Table & Dimensional Data (2.4–20 mm)
Case Studies: 304 Plate & 316 Valve Body
Decision Checklist – 60 Seconds to Choose the Right Drill
Recommended Amony ICF Drills for 304/316
FAQ – Answers from the Shop Floor
We have run the same test dozens of times. Here is what actually happens:
Thermal conductivity only 16 % of 45# steel → heat stays at the cutting edge (up to 850 °C local temperature).
Severe work hardening → surface hardness jumps from 180 HB to >350 HB in the first 0.2 mm of cut.
Chip welding & built-up edge → chips weld to the flute, torque spikes, drill snaps.
Low sulfur content → long, stringy chips that pack the flutes.
Result without internal coolant: tool life collapses to 300–450 holes on 8 mm 316 SS. With proper internal coolant → 1,100–1,400 holes.
| Series | Coolant | Tool Life (holes/edge) | Hole Tolerance | Surface Finish Ra | Cost per Hole (USD) | Winner for 304/316 |
|---|---|---|---|---|---|---|
| Amony ICF 3×D AlCrN | Dual internal | 1,240 | h7 | 0.6–0.8 µm | 0.018 | Best overall |
| UPX High-Precision (external flood) | External only | 380 | h8 | 1.2–1.8 µm | 0.062 | Precision only |
| HSS M42 (external) | External | 95 | h9 | 2.5+ µm | 0.095 | Prototyping only |
Data from 2025 production batch, 18 mm depth, 1,200 rpm, 0.22 mm/rev, 20 bar through-spindle coolant.
Diameter | Speed (m/min) | Feed (mm/rev) | Depth | Coolant Pressure 2.4–4.0 mm | 45–55 | 0.08–0.12 | 3×D | ≥20 bar 4.1–8.0 mm | 40–50 | 0.15–0.22 | 3×D | 25–40 bar 8.1–12 mm | 35–45 | 0.20–0.28 | 3×D | 30–50 bar 12.1–16 mm | 30–40 | 0.22–0.30 | 3×D | 35–60 bar
Pro tip from the shop floor: Never drop below 20 bar. At 15 bar we immediately see BUE and edge chipping on 316.
Customer previously used competitor external-coolant carbide → 420 holes/edge, frequent peck cycles, Ra 1.6 µm.
Switched to Amony ICF 3×D 8.0 mm AlCrN, 40 m/min, 0.22 mm/rev, 30 bar.
Result: 1,310 holes/edge (+212 %), no peck needed, Ra 0.7 µm, 41 % cycle time reduction.
Used 6.5 mm ICF 5×D. Tool life 980 holes/edge. Zero scrap from oversize holes for 3 consecutive weeks.
Depth ≤ 3×D and high volume? → ICF 3×D (rigid + fastest cycle)
Depth 4–8×D? → ICF 5×D or 8×D
Need mirror finish < Ra 0.8 µm? → AlCrN coating + 25 bar minimum
Machine only has external flood? → UPX Series (still better than HSS)
Diameter < 3 mm? → ZMD micro series (but expect shorter life)
Best seller for 304/316. Diameters 2.4–20 mm. Dual internal coolant. 3× tool life guarantee in production.
View Full Range →±0.01 mm precision, still solid carbide – perfect backup.
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