Selecting a deep hole drilling machine is a capital investment decision that will affect production capability for 15–25 years. The machine determines which hole diameters and depths you can drill, which methods you can use, what tolerances you can hold, and ultimately what your cost per hole will be.
Five manufacturers dominate the global market: TBT and Mollart (Tier 1, collectively ~45% market share with Kays Engineering, Entrust, and TechniDrill), UNISIG, Precihole, and HTT. Each has distinct strengths, machine series, and application specializations.
This guide provides a specification-level comparison of these manufacturers’ machine series, organized by drilling method and application.
Market Overview
The global deep hole drilling machine market is valued at approximately $257 million USD (2025), projected to reach $348 million by 2032 (CAGR 4.4%). Regional distribution: Asia-Pacific 40%, North America 25%, Europe 25%.
| Manufacturer | Headquarters | Competitive Tier | Primary Markets |
|---|---|---|---|
| TBT (Tiefbohrtechnik) | Dettingen, Germany | Tier 1 (Top 5) | Global — automotive, aerospace, energy, mold & die, defense |
| Mollart | Chessington, UK | Tier 1 (Top 5) | Global — aerospace, automotive, oil & gas, defense |
| UNISIG | Machesney Park, IL, USA | Tier 2 | North America, Europe — aerospace, mold & die, automotive |
| Precihole | Thane, India | Tier 2 | India, Global — defense, oil & gas, automotive, die & mold |
| HTT (Hochent) | Shanghai, China | Tier 2–3 | China, Global — oil & gas, hydraulic, mold & die |
TBT (Tiefbohrtechnik GmbH + Co)
TBT is the largest dedicated deep hole drilling machine manufacturer in Europe and one of the top five globally. The company produces machines for gun drilling (ELB), BTA/STS drilling, and combination processes.
ML Series (Multi-Purpose All-Rounders)
The ML series is TBT’s most versatile platform, available with 1–6 spindles, covering drilling diameters from 0.8 mm to 400 mm.
| Model | Hole Diameter | Max Depth | Spindles | Spindle Power | Speed Range | Weight |
|---|---|---|---|---|---|---|
| ML200-2 | Ø1–12 mm | 200 mm | 2 (200 mm spacing) | 25 kW total | 1,000–20,000 rpm | 7,000 kg |
| ML250 | < 100 mm | 1,550 mm | Up to 4 | — | — | — |
| ML 300-4-1450 | Ø4–20 mm (St60) | 1,450 mm | 4 (120 mm spacing) | 55 kW total | — | 13,600 kg |
| ML500 | < 50 mm | 7,000 mm | Up to 6 | — | — | — |
| ML700 | < 100 mm (max 135 mm) | 15,000 mm | 1 | — | — | — |
The ML series supports ELB (gun drilling), BTA/STS, high-speed ELB, spiralized drilling, and reduced-quantity lubrication (MQL). The ML200-2 has a maximum feed of 25,000 mm/min.
B-Series (Horizontal Large Machines)
Designed for large components with machine beds made of steel-reinforced concrete for vibration damping.
| Type | Solid Drilling Ø | Reaming/Burnishing Ø | Max Depth |
|---|---|---|---|
| B3S | 20–200 mm | Up to 400 mm | 2,000–15,000 mm |
| B4S | 20–250 mm | Up to 500 mm | 2,000–15,000 mm |
| B5S | 50–300 mm | Up to 750 mm | 2,000–15,000 mm |
| B6S | 50–400 mm | Up to 1,000 mm | 2,000–15,000 mm |
Applications: Large hydraulic cylinders, pipeline technology, double screw cylinders, aircraft landing gear.
BW300 Table Boring Machine
- Drilling capacity: 5–76 mm diameter from solid × 2,000 mm depth
- Supports gun drilling and BTA
- NC rotary clamping table, workpieces up to 20 tons
- Also capable of general milling and thread milling
Best for: Job shops that need deep hole drilling combined with milling on large workpieces.
Mollart Engineering
Mollart, based in the UK, offers one of the widest product ranges in the industry — from micro-drilling machines for holes below 0.5 mm diameter to BTA machines capable of 400 mm diameter. The company also produces combination machines that integrate gun drilling, BTA, and milling in a single setup.
Drillsprint Series (Gun Drilling)
Single-purpose gun drilling machines for precision small-hole work.
| Model | Diameter Range | Max Depth | Spindles | Notes |
|---|---|---|---|---|
| Drillsprint (standard) | Ø2–50 mm | 2,000 mm | 1–4 | General purpose gun drilling |
| Drillsprint Light Duty | Up to Ø25 mm | — | 1–4 | Lighter duty, smaller parts |
| Drillsprint 1200 twin | < 25 mm | 1,300 mm | 2 | Twin spindle production |
| Drillsprint 1500 twin | < 25 mm | 1,600 mm | 2 | Twin spindle production |
Micro Drilling Series
For holes below 6 mm diameter:
- Vertical or horizontal orientation
- 1, 2, or 4 spindles
- Hole range: Ø0.5–6 mm
- Max depth: 300 mm
- Close pitch centers for multi-hole patterns
Applications: Fuel injector nozzles, medical implants, bone screws.
HD1 Series (BTA — New Generation)
Mollart’s latest BTA machine platform, designed for solid drilling from 25 mm to 150 mm diameter.
| Parameter | Specification |
|---|---|
| Drilling capacity (solid) | 25–150 mm |
| Counter boring capacity | Up to 250 mm |
| Max drilling depth per module | 3,000 mm (extendable to 6, 9, 12 m) |
| Spindle power | 37 kW |
| Speed range | 50–2,500 rpm |
| Max torque | 5,550 Nm at 80 rpm |
| Workpiece capacity | Up to 400 mm OD × 3,000 mm long, 3 tonnes |
| Double rotation | Tool and workpiece counter-rotation |
| Accuracy | < 0.15 mm TIR over 2,000 mm |
Capabilities: push-boring, pull-boring, trepanning, counterboring, skive burnishing. Includes Mollart Monitoring System for worn or broken insert detection. Capable of drilling Inconel 718, super duplex stainless steel, and other exotic materials.
BTA BOREMASTER Series
Single and twin-spindle BTA machines for solid boring 18–150 mm diameter, 3,000 mm drilling depth.
VDF/BTA Series
| Parameter | MD1500 (1-spindle) |
|---|---|
| Drill diameter capacity | 50 mm |
| Drilling depth | 1,500 mm |
| Motor power | 11 kW |
| Speed range | 10–1,680 rpm (infinitely variable) |
| Torque | 250 Nm |
| Feed rate | 1,000 mm/min |
| Rapid traverse | 5,000 mm/min |
| Control | Fanuc |
Combination Machines
Mollart produces multi-axis machines that combine deep hole drilling with milling:
| Model | Type | Drilling Ø | Machining | X-Axis | Max Length |
|---|---|---|---|---|---|
| Prismabore | 5-axis | < 40 mm | Gundrill + BT50 milling | 1,200 mm | 2,000 mm |
| Centeplex | 6-axis | < 90 mm | Gundrill/BTA + BT50 milling | 2,000 mm | 4,500 mm |
Best for: High-value parts requiring both drilling and milling in one setup (aerospace structural components, landing gear).
B-Series (Collaboration with Vastuna)
Heavy-duty BTA machines developed in collaboration with Vastuna:
| Model | Drilling Diameter | Max Depth |
|---|---|---|
| B-2000R | Ø18–150 mm | 2,000 mm |
| B-3000R | Ø18–150 mm | 3,000 mm |
| B-4000R | Ø18–150 mm | 4,000 mm |
| B-5000R | Ø18–150 mm | 5,000 mm |
| B-6000R | Ø18–150 mm | 6,000 mm |
All models feature double rotation (tool and workpiece), automatic 4-speed gearbox, sliding pressure head, Mitsubishi/Fanuc controls.
UNISIG
UNISIG, based in the United States, builds deep hole drilling and machining centers. The company’s key differentiator is its 7-axis combination machines that integrate deep hole drilling with full milling capability.
UNI Series (Dedicated Deep Hole Drilling)
| Parameter | UNI-50BTA |
|---|---|
| Hole diameter range | 8–65 mm |
| Max centerline bore depth | 3,000 mm (modular: 1,000/1,500/2,000/3,000 mm) |
| Depth-to-diameter ratio | 100:1 or greater |
| Changeover BTA to gun drilling | ~10 minutes (without dismantling) |
| Control | Heidenhain TNC 640 |
| Counter-rotation | Standard |
Key features: High-accuracy feed system, zero-endplay spindles, preloaded ballscrew drives, multi-lingual interface with process monitoring, automatic process interruption for unattended operation.
USC-M Series (7-Axis Machining Centers)
Combine a drilling spindle (gundrill/BTA) with a CAT 50 machining spindle plus a rotary workpiece table.
| Parameter | USC-M38 | USC-M50 |
|---|---|---|
| Drilling method | Gundrill + BTA | Gundrill + BTA |
| Rated gundrill diameter | 50 mm | 50 mm |
| BTA drilling diameter | 38 mm | 50 mm |
| Drill depth | 1,500 mm | 1,830 mm |
| Drilling spindle power | 15 kW | 22 kW |
| Machining spindle | SK50/CAT 50 | SK50/CAT 50 |
| Machining spindle power | 20/25 kW | 24/30 kW |
| X-axis travel | 2,200 mm | 3,050 mm |
| Y-axis travel | 1,700 mm | 1,830 mm |
| Z-axis travel | 1,000 mm | 1,524 mm |
| Table weight capacity | 15 tons | 23 tons |
| A-axis (headstock tilt) | +30° to -15° | +30° to -15° |
| ATC option | 24–120 positions | 24–120 positions |
| Control | Heidenhain TNC 640 | Heidenhain TNC 640 |
Best for: Mold and die industry, complex aerospace components requiring drilling and milling in one setup. UNISIG reports that using gundrilling and BTA together is 5–7 times faster than gundrilling alone.
Precihole Machine Tools
Precihole, based in Thane, India, manufactures deep hole drilling machines for BTA (STS), gun drilling, and related processes, with a strong presence in defense, oil and gas, and automotive.
BVN Series (BTA Deep Hole Drilling)
Designed for continuous production drilling of large holes in shafts. Length-to-diameter ratios up to 150:1.
| Model | BVN40P | BVN65P | BVN100P | BVN180P | BVN250P |
|---|---|---|---|---|---|
| Solid drilling range | 20–40 mm | 20–65 mm | 30–100 mm | 50–180 mm | — |
| Max drilling length | 2,000 mm | 3,000 mm | 6,000 mm | 20,000 mm | — |
| Spindle power | 15 kW (20 HP) | 22 kW (30 HP) | 37 kW (50 HP) | 71 kW (95 HP) | 115 kW (154 HP) |
| Speed range | 200–2,600 rpm | 80–1,350 rpm | 50–1,350 rpm | 20–1,100 rpm | 10–700 rpm |
| Max counter boring | 100 mm | 175 mm | 300 mm | 400 mm | — |
| Max workpiece weight | 205 kg | 567 kg | 699 kg | 2,495 kg | — |
Options: Part counter-rotation, counter boring, pull boring. CNC: Fanuc or Siemens.
Best for: Artillery barrels, oilfield drill collars, long shafts.
XYBVN50 / XYGVNC Series (Column Type Multi-Axis)
For drilling multiple deep holes in tube sheets and large molds.
| Parameter | XYBVN50 |
|---|---|
| Max tube sheet weight | 12,000 kg |
| Drilling stroke | 500 mm |
| Drilling size | 19–50 mm |
| Table size | 2,000 × 2,000 mm |
| Spindle power | 22 kW |
| Spindles | 1–2 |
| L/D ratio | Up to 100:1 |
PMTC Series (Column Type — Gun/BTA Drilling + Milling)
For die/mold industry and tube sheets.
| Parameter | PMTC25 | PMTC40 | PMTC65 |
|---|---|---|---|
| Max mold plate weight | 8,000 kg | 15,000 kg | 20,000 kg |
| Drilling stroke | 1,016 mm | 1,524 mm | 2,032 mm |
| Drilling size | 0.2–1“ (5–25 mm) | 0.3–1.5“ (8–38 mm) | 0.6–2.5“ (15–65 mm) |
| Table size | 1,016 × 1,016 mm | 1,524 × 1,524 mm | 2,032 × 2,032 mm |
| Spindle power (drilling) | 7.5 kW | 15 kW | 22 kW |
| Spindle power (milling) | 7.5 kW | 15 kW | 15 kW |
| X/Y/B/W axes | Standard | Standard | Standard |
Twin Spindle Automatic BTA Machine
| Parameter | Value |
|---|---|
| Solid drilling range | 65–135 mm |
| Counter boring | Up to 180 mm |
| Max drilling depth | 1,800 mm |
| Spindle speed | 60–180 rpm |
| Coolant tank | 5,000 L |
| Filtration | 25 µm |
| Machine weight | 20 tonnes |
| CNC | Siemens |
HTT (Hochent/鸿特)
HTT, based in Shanghai, China, has specialized in deep hole drilling technology since 1997. The company manufactures machines, distributes Botek gun drills, and operates ten wholly owned deep hole drilling job shops.
KT Series (BTA Drilling/Boring)
HTT’s primary BTA machine series uses hardened rectangular guideways.
| Parameter | KT50 | KT100 | KT200 | KT350 | KT500 |
|---|---|---|---|---|---|
| Drilling capacity | 16–50 mm | 20–80 mm | 40–80 mm | 40–80 mm | 40–120 mm |
| Boring capacity | 20–50 mm | 25–100 mm | 40–200 mm | 40–350 mm | 40–500 mm |
| Feed speed | 0–500 mm/min | 0–500 mm/min | 0–500 mm/min | 0–500 mm/min | 0–500 mm/min |
| Rapid feed | 5,000 mm/min | 2,000 mm/min | 2,000 mm/min | 2,000 mm/min | 2,000 mm/min |
| Max spindle speed | 1,200 rpm | 1,000 rpm | 1,000 rpm | 670 rpm | 315 rpm |
| Spindle power | 15 kW | 11 kW | 30 kW | 30 kW | 37 kW |
| Max coolant flow | 250 L/min | 250 L/min | 400 L/min | 600 L/min | 1,000 L/min |
| Max coolant pressure | 50 bar | 50 bar | 50 bar | 50 bar | 50 bar |
General range: solid drilling Ф16–150 mm, max depth 10,000 mm.
K Series (Gun Drilling)
Single and multi-spindle gun drilling machines.
| Model | Diameter Range | Max Depth | Spindles | Notes |
|---|---|---|---|---|
| K4 | 1–50 mm | 3,000 mm | 1–4 | Shaft workpieces, standard platform |
| K6 | 1–50 mm | 3,000 mm | 1–4 | Same platform as K4 |
| K16 | 4–15 mm | 300 mm | 6 | 8,000 rpm max |
| K25 | 1–50 mm | 3,000 mm | 1–4 | Standard platform |
| K50 | 1–50 mm | 3,000 mm | 1–4 | Standard platform |
| KBA series | 1.5–20 mm | 1,000 mm | 1–3 | Off-center drilling |
| KBR series | Up to 30 mm | 1,000 mm | Multi-axis | Horizontal boring for mold industry |
Head-to-Head Comparison
By Drilling Method
| Manufacturer | Gun Drilling | BTA/STS | Trepanning | Combination (DHD + Milling) |
|---|---|---|---|---|
| TBT | ✅ ML series | ✅ ML, B-Series, BW300 | ✅ B-Series | ⚠️ Limited |
| Mollart | ✅ Drillsprint, Micro | ✅ HD1, Boremaster, B-Series | ✅ HD1 | ✅ Prismabore, Centeplex |
| UNISIG | ✅ USC-M, UNI | ✅ USC-M, UNI-50BTA | ❌ | ✅ USC-M (7-axis) |
| Precihole | ✅ PMTC, KBA | ✅ BVN series | ⚠️ Limited | ✅ PMTC |
| HTT | ✅ K series | ✅ KT series | ✅ KT options | ❌ |
By Diameter Range
| Diameter | Best Manufacturer | Model |
|---|---|---|
| < 6 mm (micro) | Mollart | Micro drill series (0.5–6 mm) |
| 1–50 mm (gun drilling) | TBT, Mollart, HTT | ML200, Drillsprint, K series |
| 8–65 mm (BTA small-medium) | UNISIG | UNI-50BTA |
| 20–250 mm (BTA medium) | TBT, Mollart, Precihole | B-Series, HD1, BVN100P |
| 50–500 mm (BTA large) | TBT, HTT, Precihole | B5S/B6S, KT500, BVN180P |
By Maximum Depth
| Depth | Best Manufacturer | Model |
|---|---|---|
| 1,500 mm | UNISIG | USC-M38 |
| 3,000 mm | Mollart, UNISIG | HD1, UNI-50BTA |
| 6,000 mm | Precihole | BVN100P |
| 10,000 mm | HTT | KT series |
| 12,000 mm | Mollart | B-Series (extended) |
| 15,000 mm | TBT | B-Series, ML700 |
| 20,000 mm | Precihole | BVN180P |
By Spindle Power
| Power | Manufacturer | Model |
|---|---|---|
| 7.5–15 kW | UNISIG, Precihole, HTT | USC-M38, PMTC25, KT50 |
| 22–37 kW | Mollart, Precihole, HTT | HD1, BVN65P, KT200 |
| 55–71 kW | TBT, Precihole | ML300, BVN180P |
| 115 kW (max) | Precihole | BVN250P |
Cost Considerations
New machine prices vary widely by configuration. The following ranges are based on published market data:
| Machine Type | New Price Range (USD) |
|---|---|
| Small gun drilling machine (single spindle) | $150,000–$250,000 |
| Production gun drilling (multi-spindle) | $300,000–$600,000 |
| BTA drilling machine (medium capacity) | $400,000–$800,000 |
| BTA drilling (large capacity, >100 mm) | $700,000–$1,500,000 |
| Combination machine (DHD + milling) | $500,000–$1,200,000 |
| CNC lathe with BTA ejector retrofit kit | $50,000–$150,000 (retrofit) |
Used machine prices range from approximately €20,000 for basic models to €250,000 for advanced units.
Regional price differences exist: HTT and Precihole machines are typically 20–40% lower in base price than equivalent TBT or Mollart machines, reflecting differences in labor costs, material sourcing, and included automation.
Selection Guide
| Priority | Recommended Manufacturer | Reason |
|---|---|---|
| Highest precision (< IT8) | TBT, Mollart | German/UK engineering, tightest tolerances |
| High-volume production | TBT, Precihole | ML multi-spindle, BVN series production focus |
| Combination drilling + milling | UNISIG, Mollart | USC-M 7-axis, Prismabore/Centeplex |
| Large diameter (> 200 mm) | TBT, Precihole, HTT | B-Series, BVN180P/N250P, KT350/500 |
| Deepest holes (> 10 m) | TBT, Precihole | B-Series (15 m), BVN180P (20 m) |
| Budget-conscious | HTT, Precihole | Lower initial investment, solid capability |
| Micro holes (< 2 mm) | Mollart | Micro drill series |
| After-sales support in Americas | UNISIG | US-based manufacturer |
| After-sales support in Asia | HTT, Precihole | China/India-based manufacturers |
| Mold & die industry | UNISIG, Precihole | 7-axis combination, PMTC column type |
For guidance on new vs. used machine purchasing decisions, see the New vs Used Deep Hole Drilling Machines Guide. For machine selection decision framework, see the Deep Hole Drilling Machine Selection Guide.