Appearance
TBT, UNISIG, and Mollart represent three distinct philosophies in BTA machine design. TBT prioritises depth capacity and combination tooling. UNISIG prioritises power and process flexibility. Mollart prioritises cost-effective production with twin-spindle configurations. The right choice depends on which philosophy matches your production requirements.
Manufacturer Overview
| Parameter | TBT Tiefbohrtechnik | UNISIG | Mollart Engineering |
|---|---|---|---|
| Country | Germany | USA | UK |
| Founded | 1950s | 2003 | 1940s |
| BTA diameter range | 20–400 mm | 8–500 mm | 18–150 mm |
| Max BTA depth | 15,000 mm | 20,000 mm | 4,000 mm |
| Primary strength | Depth + combination tooling | Power + process flexibility | Twin-spindle + cost |
| Bed construction | Steel-reinforced concrete | Heavy cast iron | Cast iron |
| Price position | Premium | Premium | Mid-range |
BTA Machine Specifications Comparison
TBT B3S
The TBT B3S is the flagship BTA machine in TBT's B-series, designed for the deepest and most demanding BTA drilling applications.
| Specification | TBT B3S |
|---|---|
| Solid drilling diameter | 20–200 mm |
| Counterboring diameter | Up to 400 mm |
| STS 3-fold combination tool | Up to 400 mm |
| Drilling depth | 2,000–15,000 mm |
| Spindle drive power | 74 kW (99 HP) |
| Counter tool holder drive | 30 kW |
| Bed material | Steel + reinforced concrete (inclined) |
| Spindle configuration | Single |
| Control | Siemens SINUMERIK |
The B3S uses an inclined bed design where gravity assists chip and coolant return. The steel-and-concrete composite construction provides vibration damping that TBT claims is superior to cast iron. The B3S supports 3-fold combination tools that can drill, bore, and roller polish in a single pass.
UNISIG B-Series
UNISIG's B-series offers four models — B380, B500, B600, and B700 — covering different swing capacities and diameter ranges.
| Specification | B380 | B500 | B600 | B700 |
|---|---|---|---|---|
| Swing over bed | 380 mm | 500 mm | 600 mm | 700 mm |
| Max solid drill Ø (nickel alloy) | 65 mm | 100 mm | 125 mm | 180 mm |
| Max solid drill Ø (carbon steel) | 80 mm | 125 mm | 150 mm | 200 mm |
| Max tool diameter | 100 mm | 160 mm | 200 mm | 300 mm |
| Depth (ballscrew) | 1.5–4 m | 2–6 m | 2–6 m | 2–6 m |
| Depth (rack & pinion) | — | 8–10+ m | 8–10+ m | 8–10+ m |
| Workpiece weight (2 steadies) | 2.0 t | 5.0 t | 5.0 t | 9.0 t |
UNISIG B-series machines support BTA drilling, trepanning, counterboring, and bottle boring. The B700 drop-bed configuration provides additional swing clearance for aerospace applications.
Mollart HD BTA and MD BTA
Mollart offers two BTA machine series: HD (heavy-duty) for larger diameters and MD (medium-duty) with twin-spindle options for higher production volume.
| Specification | HD BTA | MD BTA |
|---|---|---|
| Diameter range | 18–150 mm | 18–65 mm |
| Max drilling depth | 4,000 mm | 3,000 mm |
| Counterboring | Up to 200 mm | Standard |
| Spindle configuration | Single (heavy-duty) | Single or twin |
| Additional operations | Push boring, pull boring, trepanning | Standard BTA |
Mollart also offers the Matrix DHD, which is not a dedicated BTA machine but a 3–5 axis CNC drilling centre capable of gun drilling with optional ejector drilling capability.
Head-to-Head Comparison
Diameter Range
| Diameter Range | Best Choice | Reason |
|---|---|---|
| 8–18 mm | UNISIG | Only manufacturer offering BTA below 18 mm on some models |
| 18–65 mm | Mollart MD BTA (twin) | Twin-spindle option doubles production at lower cost |
| 65–150 mm | UNISIG B500/B600 | Higher spindle power (up to 100 kW) than TBT or Mollart |
| 150–200 mm | UNISIG B700 or TBT B3S | Comparable; depth requirement decides |
| 200–400 mm | TBT B3S | 3-fold combination tools up to 400 mm |
Drilling Depth
TBT B3S offers 15 m as standard depth, making it the best choice for applications requiring very deep BTA holes without upgrading to rack-and-pinion drives.
UNISIG B-series with rack-and-pinion drive can exceed 20 m, surpassing TBT's standard depth, but requires the optional drive system.
Mollart HD BTA is limited to 4 m, making it unsuitable for deep BTA applications.
Spindle Power
UNISIG offers the highest spindle power — up to approximately 100 kW (130 HP) on the B500, compared to TBT B3S at 74 kW (99 HP). This gives UNISIG an advantage for large-diameter drilling in difficult materials such as nickel alloys and stainless steel.
Bed Construction
| Manufacturer | Bed Type | Advantage |
|---|---|---|
| TBT | Steel + reinforced concrete (inclined) | Superior vibration damping, gravity chip return |
| UNISIG | Heavy cast iron with hardened guideways | Proven rigidity, traditional precision |
| Mollart | Cast iron | Standard construction, adequate for mid-range |
The bed design difference reflects each manufacturer's engineering philosophy. TBT's concrete bed is unique in the industry and provides measurable vibration damping for deep holes where chatter is a risk. UNISIG's cast iron beds are conventional but proven over decades of BTA machine building.
Automation and Integration
| Capability | TBT | UNISIG | Mollart |
|---|---|---|---|
| Gantry loading | Yes | Yes | Yes |
| Robot integration | Yes (ML series) | Yes | Yes |
| Combined BTA/gundrill | Separate machines | UNI-50BTA (10-min changeover) | Optional on Matrix DHD |
| Process monitoring | Siemens (torque, pressure, force) | Custom (full suite) | Fanuc (torque, pressure) |
| Multi-spindle BTA | Up to 6 spindles (ML500) | Single spindle only | Twin spindle (MD BTA) |
UNISIG's UNI-50BTA is unique in offering a 10-minute changeover between gun drilling and BTA on the same machine. TBT offers both processes but requires separate machine configurations. Mollart's Matrix DHD can add BTA capability but is primarily a gun drilling platform.
Application-Specific Recommendations
| Application | Recommended | Rationale |
|---|---|---|
| Deep oil and gas components (10–15 m) | TBT B3S | 15 m standard depth, combination tooling reduces passes |
| Aerospace landing gear (large diameter) | UNISIG B700 | Highest spindle power, large swing, drop-bed option |
| Hydraulic cylinder production (high volume) | Mollart MD BTA (twin) | Twin spindles, 30% lower capital than TBT/UNISIG |
| Heat exchanger tube sheets (multi-hole) | TBT ML500 (6-spindle) | Highest spindle count for parallel drilling |
| Defense/gun barrel drilling | UNISIG (small gundrill) or TBT | Both strong; UNISIG offers gundrill-BTA changeover |
| General job shop (varied work) | UNISIG B500 | Broadest diameter range in one machine |
| Budget-constrained BTA entry | Mollart HD BTA | Lower capital cost, good 150 mm capacity |
Cost Comparison
| Factor | TBT | UNISIG | Mollart |
|---|---|---|---|
| B-series BTA machine (typical) | $400,000–900,000 | $400,000–1,000,000 | $300,000–600,000 |
| Installation and training | Included or extra | Included | Extra |
| Typical lead time | 8–12 months | 6–10 months | 6–9 months |
| Spare parts availability | Germany (global shipping) | USA (global shipping) | UK (global shipping) |
| Resale value (10 years) | 25–35% of new | 20–30% of new | 15–25% of new |
Tip: Total cost of ownership for a BTA machine should include coolant system maintenance, spindle rebuilds at 10,000–15,000 hours, and guideway reconditioning at 15–20 years. These costs are similar across all three manufacturers.
FAQ
Which BTA drilling machine has the deepest drilling capacity?
TBT B3S offers 15 m as standard. UNISIG B-series with rack-and-pinion drive can exceed 20 m but requires the optional drive system. Mollart HD BTA is limited to 4 m.
Which BTA machine has the highest spindle power?
UNISIG B500 offers up to approximately 100 kW (130 HP), compared to TBT B3S at 74 kW (99 HP) and Mollart's unspecified but lower power ratings.
Can UNISIG machines do both BTA and gun drilling?
Yes. The UNI-50BTA changes between BTA and gun drilling in approximately 10 minutes. TBT offers both processes but on separate machines. Mollart offers both on the Matrix DHD with optional ejector drilling.
Is TBT's concrete bed better than UNISIG's cast iron bed?
The steel-concrete bed provides superior vibration damping for deep hole applications where chatter is a concern. Cast iron is more traditional and proven. Both produce acceptable results within their design parameters.
Which manufacturer offers multi-spindle BTA machines?
TBT offers up to 6 spindles on the ML500 series. Mollart offers twin spindles on the MD BTA. UNISIG B-series BTA machines are single-spindle only.
How much does a BTA drilling machine cost from these manufacturers?
TBT and UNISIG BTA machines range from $400,000 to $1,000,000 depending on configuration. Mollart HD BTA typically costs $300,000–600,000.
Which BTA machine is best for high-volume production?
TBT ML500 with 6 spindles for maximum parallel drilling, or Mollart MD BTA with twin spindles for lower capital cost. UNISIG single-spindle B-series is better suited for job shop and mixed-production environments.
What is the lead time for a BTA drilling machine?
6–12 months depending on configuration and manufacturer workload. TBT and UNISIG tend toward the longer end for custom configurations. Mollart is typically 6–9 months.
Do these manufacturers offer installation and training?
UNISIG includes installation and training in their standard package. TBT offers it as part of the purchase. Mollart typically provides installation support but training may be quoted separately.
Which manufacturer has the best support in North America?
UNISIG has the strongest North American presence (Wisconsin headquarters). TBT is represented by Nagel Precision in Michigan. Mollart supports North America through Bourn-Koch (Oregon) and direct from the UK.
Conclusion
TBT, UNISIG, and Mollart each occupy distinct positions in the BTA drilling machine market. TBT leads in depth capacity (15 m standard), diameter range (up to 400 mm with combination tools), and multi-spindle configurations (up to 6 spindles). UNISIG leads in spindle power (100 kW), process flexibility (10-minute BTA/gundrill changeover), and swing capacity (700 mm on the B700). Mollart leads in twin-spindle BTA production and lower capital cost. The correct choice depends on whether depth (TBT), power and flexibility (UNISIG), or cost-effective twin-spindle production (Mollart) is the primary requirement.