Processes
Stick (SMAW), DC TIG (GTAW), Air carbon arc cutting and gouging (CAC-A)
Miller Stick / Engine-Drive Support
Big Blue 450 Duo CST
Dual-operator diesel engine-driven stick/TIG welder with two CST-style outputs for field productivity.
Stick (SMAW)DC TIG (GTAW)Air carbon arc cutting and gouging (CAC-A)
Heavy industrial dual-operator diesel engine-drive
Welding range
Separate outputs: 5 - 225 A each side. Single side: 5 - 280 A. Paralleled: 10 - 450 A.
Engine
Mitsubishi S4L2 diesel, 24.7 hp at 1,800 rpm
Auxiliary power
Single-phase. Peak: 10,500 W. Continuous: 8,900 W.
Weight
1,064 lb. (483 kg)
Class
Heavy industrial dual-operator diesel engine-drive
Machine Packages
| Stock number | Catalog package |
|---|---|
| 907866 | Mitsubishi |
Compatible Accessories
Full KVA Adapter Cord
300517 Full KVA adapter cord listed for Bobcat, Trailblazer, and Big Blue engine-drive models.
Support path pendingFull KVA Plug Kit
119172 Single-phase 120/240 V, 50 A plug kit listed for Bobcat, Trailblazer, and Big Blue models.
Support path pendingProtective Cover
195301 Protective cover for Big Blue 400 Pro, Big Blue 400 PipePro, and Big Blue 450 Duo CST.
Support path pendingHWY-Mid Frame Trailer
Trailer path listed for Bobcat, Trailblazer, Big Blue 400 Pro, Big Blue 400 PipePro, and Big Blue 450 Duo CST.
Support path pendingCompatible Torches / Guns / Feeders
No torch, gun, or feeder path is connected yet for this machine.
Miller Catalog Accessories
These accessories are placed here only when the Miller catalog names this machine, torch, feeder, or family path. Verify plug style, voltage, package, and serial-specific details before ordering.
| Part | Accessory | Catalog fitment | Source / path |
|---|---|---|---|
| 301438 | HWY-Mid Frame Trailer | For Bobcat, Trailblazer, Big Blue 400 Pro, Big Blue 400 PipePro, and Big Blue 450 Duo CST. | Catalog p. 125 Open support path |
| 301338 | HWY-225 Trailer | For Big Blue models. | Catalog p. 125 Open support path |
Full machine details
Welding Output
- Separate: 175 A at 27 V each side, 100% duty cycle
- Paralleled: 350 A at 34 V, 100% duty cycle
Key Support Notes
- Two separate outputs with Tweco-style receptacles
- Simple process select for E6010 and E7018 stick electrodes
- Vandalism lockout kit protects control panels
- Dual-operator productivity
Dimensions
H: 32 in. / 37 in. to top of exhaust, W: 26.25 in., D: 56 in.
Source: Miller Electric 2026 Full-line Catalog, catalog page 87, literature ED/5.8. Machine and accessory relationships are source-backed catalog references. Amazon purchase links stay separate and only appear after independent product verification.