This reference compiles cutting speed and feed rate data from manufacturers including ISCAR, Kennametal, Allied Machine, Nachi/AHB, and technical handbooks. All values are starting recommendations — adjust based on machine rigidity, coolant delivery, and observed chip formation.
Formulas:
- Cutting speed: Vc (m/min) = π × D × n ÷ 1,000 (D = drill diameter in mm, n = spindle RPM)
- Spindle speed: n (RPM) = 1,000 × Vc ÷ (π × D)
- Feed rate (mm/min): Vf = f × n (f = feed per revolution in mm/rev)
Source: ISCAR Drilling Handbook.
1. Gun Drilling Parameters
Gun drilling uses a single-lip cutting tool with internal coolant. Feed rates are lower than BTA because the V-shaped chip flute has limited clearance area (~22–26% of hole cross-section). For a detailed explanation of the process, see The Four Deep Hole Drilling Methods Explained.
Table 1A: Gun Drilling — Carbide-Tipped Tools
| Material Group | Specific Material | Vc (m/min) | Feed f (mm/rev) — by drill diameter |
|---|---|---|---|
| Ø 3–6 mm | |||
| Low-carbon steel | 1010, 1020, A36 | 80–120 | 0.008–0.025 |
| Medium-carbon steel | 1045, 1050 | 60–90 | 0.008–0.020 |
| Alloy steel | 4140, 4340 (annealed) | 50–80 | 0.005–0.018 |
| Alloy steel (hardened) | 4140, 4340 (35–42 HRC) | 30–50 | 0.005–0.015 |
| Stainless steel (austenitic) | 304, 316 | 25–45 | 0.005–0.015 |
| Stainless steel (martensitic) | 410, 420 | 30–55 | 0.005–0.015 |
| Aluminum (wrought) | 6061, 7075 | 80–160 | 0.010–0.035 |
| Aluminum (cast) | A356, 319 | 60–120 | 0.008–0.025 |
| Titanium alloy | Ti-6Al-4V | 20–40 | 0.005–0.015 |
| Tool steel (annealed) | P20, H13, A2 | 35–60 | 0.005–0.015 |
| Copper alloys | Brass, bronze | 60–120 | 0.008–0.030 |
| Grey cast iron | Class 25–40 | 50–80 | 0.008–0.025 |
Sources: ISCAR Drilling Handbook (deep hole drilling section); AHB/Nachi gun drilling table; AIMS Industrial cutting speeds reference.
Table 1B: Gun Drilling — HSS-Co Tools
For shops using HSS-cobalt gun drills (less common than carbide but still used for smaller diameters and lower production volumes):
| Material | Vc (SFM) | Vc (m/min) |
|---|---|---|
| Carbon & alloy steels | 50–65 | 15–20 |
| Alloy / hardened steels | 40–52 | 12–16 |
| Stainless & mold steels | 30–40 | 9–12 |
| Titanium alloys | 10–20 | 3–6 |
| Aluminum / nonferrous | 83–115 | 25–35 |
Source: AHB/Nachi gun drilling table (HSS-Co tooling).
2. BTA Drilling Parameters
BTA (Single-Tube System) drilling uses multiple cutting edges with internal chip evacuation through a hollow drill tube. The larger chip clearance area (>60% of hole cross-section) allows feed rates 5–10× higher than gun drilling at the same diameter.
Table 2A: BTA Drilling — Carbide Insert Tooling
| ISO Group | Material | Vc (m/min) | Feed f (mm/rev) — by drill diameter |
|---|---|---|---|
| Ø 10–20 mm | |||
| P1–P2 | Low-carbon steel (< 0.25% C) | 80–130 | 0.04–0.16 |
| P3–P4 | Medium-carbon / low-alloy steel (annealed) | 60–100 | 0.04–0.14 |
| P5–P6 | High-alloy steel / tool steel / hardened | 30–60 | 0.03–0.10 |
| M1–M3 | Stainless steel (austenitic, duplex) | 40–80 | 0.03–0.12 |
| K1–K3 | Grey and nodular cast iron | 70–120 | 0.05–0.20 |
| N1–N3 | Aluminum (wrought and cast) | 80–170 | 0.05–0.18 |
| S1–S4 | High-temp alloys (Inconel, Hastelloy) | 15–35 | 0.02–0.08 |
| S5 | Titanium alloys | 20–40 | 0.03–0.10 |
| H1–H4 | Hardened steel (45–55 HRC) | 15–30 | 0.02–0.06 |
Sources: ISCAR FINEBEAM BTA data (HF chipbreaker); Kennametal BTA drilling catalog; Allied Machine T-A drilling guide.
Table 2B: BTA Drilling — Inch Units (ISCAR FINEBEAM)
| Material | Vc (SFM) | Feed (IPR) — Ø 1.0–1.7 in | Feed (IPR) — Ø 1.7–3.5 in |
|---|---|---|---|
| Non-alloy steel (annealed) | 230–425 | 0.004–0.016 | 0.006–0.018 |
| Low-alloy steel (275 HB) | 180–360 | 0.004–0.016 | 0.008–0.018 |
| Stainless steel (austenitic) | 130–360 | 0.004–0.016 | 0.008–0.018 |
| Grey cast iron | 165–360 | 0.004–0.015 | 0.009–0.016 |
| Aluminum (wrought) | 215–490 | 0.004–0.013 | 0.009–0.014 |
Source: ISCAR FINEBEAM catalog (HF chipbreaker).
3. High-Temperature Alloys (Inconel, Hastelloy, Titanium)
For detailed Inconel 718 and Hastelloy X parameters with specific case studies, see our dedicated nickel superalloy guide.
| Material | Method | Vc (m/min) | Feed (mm/rev) | Coolant Pressure | Notes |
|---|---|---|---|---|---|
| Inconel 718 | Gun drilling | 10–25 | 0.02–0.05 | 70–100 bar | TiAlN coating required |
| Inconel 718 | BTA | 15–25 | 0.04–0.12 | 70–100 bar | Use K20 grade guide pads |
| Inconel 625 | Gun drilling | 10–20 | 0.02–0.05 | 70–100 bar | Similar to 718, slightly lower speeds |
| Hastelloy X | Gun drilling | 8–18 | 0.015–0.04 | 70–100 bar | Most difficult of the three |
| Hastelloy X | BTA | 12–20 | 0.03–0.08 | 70–100 bar | 26×D depth achievable (Neway AeroTech) |
| Ti-6Al-4V | Gun drilling | 20–40 | 0.02–0.05 | 40–70 bar | See titanium guide |
| Ti-6Al-4V | BTA | 20–40 | 0.05–0.16 | 40–70 bar | Lower conductivity requires high pressure |
Sources: ISCAR Drilling Handbook (S group); Neway AeroTech case studies; YG-1 HRSA Solutions; Oezkaya et al., IJMTM 2016; nickel superalloys guide.
4. L/D Correction Factors
As hole depth increases relative to diameter, cutting parameters must be reduced. The chip evacuation path becomes longer, friction increases, and coolant effectiveness decreases.
Table 4A: Speed and Feed Reduction by L/D Ratio
| L/D Ratio | Speed (Vc) Factor | Feed (f) Factor | Source |
|---|---|---|---|
| 3×D | 1.00 (no reduction) | 1.00 | RIGPL / Allied Machine |
| 4×D | 0.85 | 0.90 | Ukrainian K_lv table |
| 5×D | 0.75 | 0.80 | RIGPL / Norseman |
| 6×D | 0.65–0.70 | 0.75 | Allied Machine (6×D = 0.90 for both) |
| 8×D | 0.60 | 0.60 | RIGPL |
| 10×D | 0.50 | 0.50 | Ukrainian K_lv table |
| 15–20×D | 0.40–0.50 | 0.40–0.50 | Allied Machine extrapolated |
Sources: RIGPL catalog; Allied Machine technical guide (TG-SFC); Ukrainian technical source (K_lv coefficient); Norsemandrill.
Table 4B: Combined Reduction Recommendations — Summary
| L/D Range | Speed Reduction | Feed Reduction | Notes |
|---|---|---|---|
| ≤ 3×D | None | None | No correction needed |
| 3–5×D | 10–25% | 10–20% | Begin pecking above 3×D |
| 5–8×D | 25–40% | 20–40% | High-pressure coolant recommended |
| 8–12×D | 40–50% | 40–50% | Through-tool coolant essential |
| 12–20×D | 50–60% | 50–60% | Dedicated deep hole equipment required |
Sources: Consolidated from RIGPL, Allied Machine, CNC Support, and Norsemandrill.
Application Example
10 mm diameter gun drill, 100 mm drilling depth (L/D = 10:1) in 1045 steel:
| Step | Calculation | Result |
|---|---|---|
| Base Vc for 1045 steel | From Table 1A | 60–90 m/min |
| L/D correction (10×D) | Multiply by 0.50 | 30–45 m/min |
| Spindle speed | n = 1,000 × 37.5 ÷ (π × 10) | ≈ 1,200 RPM |
| Base feed for 10 mm dia | From Table 1A | 0.015–0.040 mm/rev |
| L/D correction (10×D) | Multiply by 0.50 | 0.008–0.020 mm/rev |
| Feed rate (mm/min) | Vf = 0.014 × 1,200 | ≈ 17 mm/min |
Result: Start at 1,200 RPM, 17 mm/min feed, and adjust based on chip formation and tool wear.
5. Coolant Pressure and Flow Rate
BTA and gun drilling require different coolant pressure and flow characteristics. See the safety guide for deep hole drilling for hazard information on high-pressure coolant systems.
Table 5A: Coolant Pressure by Method and Diameter
| Method | Diameter Range | Recommended Pressure | Notes |
|---|---|---|---|
| Gun drilling | 3–6 mm | 80–150 bar | Higher pressure needed for small diameters |
| Gun drilling | 6–20 mm | 50–100 bar | |
| Gun drilling | 20–50 mm | 40–80 bar | |
| BTA drilling | 10–30 mm | 50–100 bar | VDI 3209 reference |
| BTA drilling | 30–70 mm | 30–70 bar | Larger diameters need lower pressure |
| BTA drilling | 70–200 mm | 20–50 bar | Flow rate becomes the limiting factor |
Sources: ISCAR Drilling Handbook (coolant pressure charts); VDI 3209 Blatt 1; JimmyTool.
Table 5B: Coolant Flow Rate — BTA Drilling (Approximate)
| Drill Diameter | Flow Rate (l/min) | Notes |
|---|---|---|
| 10 mm | 30–60 | Minimum for chip transport |
| 20 mm | 80–150 | |
| 30 mm | 150–250 | |
| 40 mm | 200–350 | |
| 60 mm | 300–450 | ISCAR max reference ≈ 400 l/min |
Source: ISCAR Drilling Handbook (DTS/BTA coolant volume charts); JimmyTool.
The coolant flow velocity must be sufficient to transport chips through the drill tube. A 10% drop in coolant pressure during operation is a reliable early warning of chip blockage or a developing crack (JimmyTool).
6. Coolant Type Recommendations
| Material | Recommended Coolant | Concentration | Notes |
|---|---|---|---|
| Carbon & alloy steels | Neat oil or oil-based | — | Best lubrication and EP properties |
| Stainless steel | Neat oil or semi-synthetic | 8–12% | Work-hardening resistance |
| Aluminum | Semi-synthetic or mineral oil | 6–10% | Avoid TiAlN coating (chemical reaction) |
| Titanium | Neat oil or heavy-duty emulsion | 8–12% | Thermal conductivity is critical |
| Inconel / Hastelloy | Neat oil | — | EP additives essential |
| Cast iron | Emulsion or semi-synthetic | 5–8% | Graphite provides some lubrication |
| Tool steels | Neat oil | — | Heat management is priority |
General filtration requirement for all deep hole drilling: < 20 microns. Particles larger than this cause abrasive guide pad wear (JimmyTool; UNISIG Technical Reference).
7. Starting Parameters by Material — Quick Reference
Steel (1045, 4140 annealed)
| Method | Ø (mm) | Vc (m/min) | f (mm/rev) | Coolant (bar) |
|---|---|---|---|---|
| Gun drill | 6 | 70 | 0.018 | 80 |
| Gun drill | 12 | 70 | 0.035 | 60 |
| Gun drill | 20 | 65 | 0.050 | 50 |
| BTA | 20 | 80 | 0.15 | 60 |
| BTA | 40 | 80 | 0.25 | 40 |
Stainless Steel (304, 316)
| Method | Ø (mm) | Vc (m/min) | f (mm/rev) | Coolant (bar) |
|---|---|---|---|---|
| Gun drill | 6 | 35 | 0.012 | 100 |
| Gun drill | 12 | 35 | 0.025 | 80 |
| BTA | 20 | 55 | 0.10 | 70 |
Aluminum (6061, 7075)
| Method | Ø (mm) | Vc (m/min) | f (mm/rev) | Coolant (bar) |
|---|---|---|---|---|
| Gun drill | 6 | 120 | 0.025 | 50 |
| Gun drill | 12 | 120 | 0.050 | 40 |
| BTA | 20 | 130 | 0.20 | 30 |
Titanium (Ti-6Al-4V)
| Method | Ø (mm) | Vc (m/min) | f (mm/rev) | Coolant (bar) |
|---|---|---|---|---|
| Gun drill | 6 | 30 | 0.012 | 70 |
| Gun drill | 12 | 30 | 0.025 | 50 |
| BTA | 20 | 30 | 0.10 | 50 |
Detailed titanium parameters can be found in the titanium deep hole drilling guide.
Inconel 718
| Method | Ø (mm) | Vc (m/min) | f (mm/rev) | Coolant (bar) |
|---|---|---|---|---|
| Gun drill | 6 | 18 | 0.010 | 100 |
| Gun drill | 12 | 18 | 0.020 | 80 |
| BTA | 20 | 20 | 0.08 | 100 |
Cast Iron (Grey, Class 30)
| Method | Ø (mm) | Vc (m/min) | f (mm/rev) | Coolant (bar) |
|---|---|---|---|---|
| Gun drill | 6 | 65 | 0.018 | 50 |
| Gun drill | 12 | 65 | 0.035 | 40 |
| BTA | 20 | 100 | 0.22 | 40 |
For stainless steel and aluminum parameters, see our dedicated stainless steel guide.
8. Chipbreaker Selection (BTA)
ISCAR classifies BTA chipbreakers into two types for the FINEBEAM system:
| Chipbreaker | Best For | Feed Range | Chip Form |
|---|---|---|---|
| HF (General purpose) | Steels, stainless, cast iron, aluminum | Medium to high | Compact C-shaped chips |
| G (Improved chip control) | Long-chipping materials, low-carbon steel | Medium | Shorter, well-broken chips |
Source: ISCAR FINEBEAM BTA catalog.
Select the chipbreaker based on observed chip form. Ideal chips for BTA drilling are C-shaped, approximately 3–4× as long as wide. Chips that are too long indicate the need for a shorter chipbreaker; chips that are too short (dusty) indicate excessive chip breaking.
9. Tool Coatings
| Coating | Max Temp | Best Applications | Notes |
|---|---|---|---|
| TiN | 600°C | General steel, cast iron | Low-cost, limited heat resistance |
| TiAlN | 850°C | Alloy steel, stainless, Inconel | Best all-around for deep hole drilling |
| AlTiN | 850°C | High-temp alloys, hardened steel | Higher aluminum content = better oxidation resistance |
| AlCrN | 900°C | Titanium, high-heat situations | Best thermal stability |
| TiCN | 450°C | Aluminum, nonferrous | Low friction, reduces BUE on aluminum |
Source: UPC research; YG-1 HRSA Solutions; multiple coating manufacturer data.
Key Sources
- ISCAR Drilling Handbook — comprehensive cutting data for gun drilling, BTA, and DTS methods (pages 260–310)
- ISCAR FINEBEAM BTA catalog — inch-unit speeds and feeds with chipbreaker selection
- Kennametal Master Catalog (Vol. 2, Rotating Tools) — BTA drilling parameters by material group
- Allied Machine, “T-A Drilling Technical Guide” (TG-SFC) — material-specific parameters and L/D correction factors
- AHB/Nachi, Cutting Tools Catalog — gun drilling speed/feed tables for HSS-Co tools
- AIMS Industrial, “Cutting Speeds & Feeds Reference Chart” — general drilling data
- RIGPL Catalog — L/D correction factor table
- Ukrainian technical source (Table 2.1, K_lv coefficient) — cutting speed correction by depth
- Norsemandrill, “Feeds & Speeds for Drills” — rule-of-thumb adjustment guidelines
- CNC Support, “Deep Holes and G83 Multi-Peck Drill Cycle” — reduction percentages
- YG-1, “Machining Heat-Resistant Super Alloy (HRSA)” — high-pressure coolant recommendations
- Neway AeroTech case studies — Inconel 718 and Hastelloy X production data
- VDI 3209 Blatt 1 — BTA coolant pressure reference
- JimmyTool — coolant pressure monitoring and filtration requirements
- Oezkaya et al., IJMTM, 2016 — coolant pressure effect on tool life in nickel alloys