Big Blue® 450 Duo CST Engine-Driven Welder | MillerWelds

Big Blue® 450 Duo CST™

The Big Blue 450 Duo CST is a rugged, compact, fuel-efficient diesel engine driven welder that provides 2 superior arcs in one economical package.


Quiet Operation
At just 72.2 decibels at 23 feet (7 m), it's quieter than most single-operator models, improving jobsite communication and safety.   Learn More
Adaptive Hot Start™ For Stick Arc Starts
Automatically increases the output of a weld should the start require it.  Prevents the electrode from sticking and creating an inclusion.
Superior Stick Arc Performance
Even on the difficult-to-run electrodes like E6010   Learn More
High Efficiency
Three-Phase, rotating-field auxiliary power unit requires less fuel and horsepower to operate.   Learn More
Remote Amperage Control
Provided through 14-pin receptacle on front of the machine.  This permits use of standard and wireless remote amperage control devices.   Learn More
Multi-function Fuel Gauge
Displays fuel level and engine hours, and can be customized to set oil change interval reminders. In the case of high coolant temperature, low oil pressure, or low fuel level, the engine will shut down to prevent damage, or make restarting easier.
Heavy-Duty Low-Speed Mitsubishi S4L2 Industrial Diesel Engine
Used in industrial applications around the world, the S4L2 is designed to run 10,000 hours before major overhaul. Backed by worldwide support and service.
Vandalism Lockout Kit
Lockable hinged steel panel protects front control panels and ignition switch.

Not Included

  • Weld leads



Air Carbon Arc Cutting and Gouging (CAC-A)
Stick (SMAW)

General Specifications

Title Big Blue® 450 Duo CST™
Industries Interests Construction and Fabrication
Amperage 5 A - 450 A
Weldable Metals Stainless Steel
Rated Carbon Diameter 3/16 in (4.8 mm)
Current Type DC
Max Open Circuit Voltage 77 VDC
Portability Lift Eye (Standard)
Trailer (Optional)
Cold Weather Starting Aids Glow Plugs
Engine Brand Mitsubishi
Engine Compliance T4F
Engine Idle Speed 1800 RPM
Engine Weld Speed 1800 RPM
Fuel Tank Size 10 gal. (37.8 L)
Fuel Type Diesel
Horsepower 24.7 hp
Weld Output CC
Rated Output Separate (Dual Outputs) 175 A at 27 V, 100% duty cycle,Paralleled (Single Output) 350 A at 27 V, 100% duty cycle
Single Phase Auxiliary Continuous Power 8900 W
Single Phase Auxiliary Peak Power 10500 W
Sound Rating 71 dB (96 Lwa)
Applications Fabrication
Field Welding
Net Width 58 in
Net Height 34 in
Net Length 28 in
Net Weight 1064 lbs
Warranty 3 Years
Miller's True Blue Warranty


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