Deep Hole Drilling Parameters Quick Reference

This guide consolidates recommended cutting parameters for deep hole drilling across all methods and common engineering materials into a single quick-reference format. Parameters are starting recommendations — adjust based on machine condition, tool condition, and specific application requirements.

Gun Drilling Parameters

Cutting Speed by Material

Material GroupBHNCutting Speed (m/min)Cutting Speed (SFM)
Low-carbon steel (< 0.25% C)100–15080–180260–590
Medium-carbon steel (0.25–0.55% C)150–25060–120200–390
Alloy steel (4140, 4340) annealed200–30050–100160–330
Alloy steel hardened (HRC 30–45)300–45020–4065–130
Tool steel200–30030–60100–200
Stainless 303/304150–20040–70130–230
Stainless 316150–20035–60115–200
Stainless 17-4PH (aged)350–40015–3050–100
Gray cast iron150–25050–100160–330
Ductile iron200–30040–80130–260
Aluminum 606180–100100–300330–980
Aluminum 7075150–17580–200260–660
Brass (free machining)80–12080–200260–660
Bronze150–25040–80130–260
Titanium Grade 2 (commercially pure)200–25020–4065–130
Titanium 6Al-4V300–38015–3050–100
Inconel 718 (annealed)350–40010–2033–65
Inconel 718 (aged)400–5006–1220–40
Hastelloy X200–25015–2550–80
Copper (pure)80–10030–60100–200
Beryllium copper200–30020–4065–130
Plastics (PEEK, Nylon)50–150160–490
Hardened steel (HRC 50–60)500–6505–1516–50

Feed Rate by Diameter (Gun Drilling)

Drill Diameter (mm)Feed Rate (mm/rev) — SteelFeed Rate — Cast IronFeed Rate — Aluminum
1–3 mm0.005–0.0150.008–0.0200.010–0.030
3–6 mm0.010–0.0200.015–0.0300.020–0.050
6–10 mm0.015–0.0250.020–0.0400.030–0.060
10–15 mm0.018–0.0300.025–0.0500.040–0.080
15–25 mm0.020–0.0350.030–0.0550.050–0.100
25–40 mm0.025–0.0400.035–0.0600.060–0.120
40–50 mm0.030–0.0450.040–0.0650.070–0.140

Coolant Pressure by Diameter (Gun Drilling)

Drill Diameter (mm)Minimum Pressure (bar)Recommended (bar)Minimum Flow (L/min)
1–3 mm120120–2005–15
3–6 mm80100–15010–30
6–10 mm6080–12015–50
10–15 mm5070–10025–60
15–25 mm4050–8040–80
25–40 mm3040–7060–120
40–50 mm2530–6080–150

BTA Drilling Parameters

Cutting Speed by Material

Material GroupBHNCutting Speed (m/min)Cutting Speed (SFM)
Low-carbon steel100–15070–140230–460
Medium-carbon steel150–25060–120200–390
Alloy steel (4140) annealed200–30050–100160–330
Alloy steel hardened (HRC 30–45)300–45015–2550–80
Stainless 304150–20040–70130–230
Gray cast iron150–25050–90160–300
Ductile iron200–30040–80130–260
Aluminum80–15080–250260–820
Titanium 6Al-4V300–38012–2540–80
Inconel 718 (annealed)350–40010–1833–60
Brass/Bronze80–25050–150160–490

Feed Rate by Diameter (BTA)

Drill Diameter (mm)Feed Rate (mm/rev) — SteelFeed Rate — Cast IronFeed Rate — Aluminum
18–25 mm0.10–0.220.15–0.300.15–0.45
25–40 mm0.12–0.280.18–0.350.20–0.55
40–65 mm0.15–0.350.22–0.450.25–0.65
65–100 mm0.18–0.400.28–0.500.30–0.75
100–150 mm0.22–0.450.32–0.550.35–0.85
150–200 mm0.28–0.500.38–0.600.40–0.90

Coolant Pressure by Diameter (BTA)

Drill Diameter (mm)Pressure (bar) — MinimumPressure (bar) — RecommendedFlow (L/min)
18–25 mm2535–50100–180
25–40 mm2230–45150–250
40–65 mm2025–40200–350
65–100 mm1820–35300–500
100–150 mm1518–30400–650
150–200 mm1215–25500–800

Ejector Drilling Parameters

Cutting Speed by Material

Same as BTA — both use similar carbide insert grades and geometries.

Feed Rate by Diameter (Ejector)

Approximately 90% of BTA feed rates for the same material and diameter. Use BTA feed rate table above, then reduce by 10%.

Coolant Pressure by Diameter (Ejector)

Drill Diameter (mm)Pressure (bar)Flow (L/min)
18–25 mm30–4080–120
25–40 mm25–35120–180
40–65 mm20–30150–250
65–100 mm18–25200–350
100–150 mm15–22250–400
150–200 mm12–20300–450

Depth Ratio Adjustment Factors

Speed Adjustment

Depth RatioGun DrillingBTAEjector
Up to 10:1100%100%100%
10:1 to 30:195%100%100%
30:1 to 60:185%90%90%
60:1 to 100:175%80%80%
100:1+65%N/AN/A

Feed Adjustment

Depth RatioGun DrillingBTAEjector
Up to 10:1100%100%100%
10:1 to 30:195%100%100%
30:1 to 60:180%90%85%
60:1 to 100:170%75%75%
100:1+60%N/AN/A

Starting Parameters by Common Application

ApplicationMethodSpeed (m/min)Feed (mm/rev)Coolant Pressure (bar)
Gun barrel, chrome-moly steelGun drilling25–400.015–0.025100–150
Fuel injector, stainless steelGun drilling40–600.012–0.02080–120
Landing gear, 300M steelGun drilling15–250.010–0.020100–150
Crankshaft, steelGun drilling60–800.018–0.02860–80
Heat exchanger tube sheet, steelBTA60–800.15–0.2525–40
Valve body, carbon steelBTA50–700.12–0.2030–45
Hydraulic cylinder, steelBTA60–800.18–0.3025–35
CNC lathe retrofit general, steelEjector50–700.15–0.2525–35
Medical bone screw, 316LGun drilling30–450.008–0.015100–150
Titanium aerospace componentGun drilling15–250.010–0.020120–180

Summary

Quick-reference tables for deep hole drilling parameters must account for material, method, diameter, and depth ratio. Always start at the lower end of the recommended range and adjust upward based on chip shape (target: C-shaped chips). Monitor coolant pressure at the tool (not just the pump) — pressure drop from pump to tool can be 20–40%. For detailed parameter explanations, see the deep hole drilling parameters overview, cutting speed optimization, and feed rate selection guide.