STAHLWERK CTM-250 ST Combination Welding Machine TIG + MIG/MAG + MMA/ARC + CUT/Plasma with 200 Amps and 45 Amp Plasma Function P/N6910

The STAHLWERK CTM-250 ST is a compact yet highly capable multi-process inverter designed to handle a wide range of welding and cutting tasks from a single machine. This 4-in-1 unit brings together MIG/MAG, TIG, MMA (stick) welding and an integrated plasma cutting function, delivering up to 200 A output for use in workshops, site work, and serious home fabrication projects.

A wide selection of adjustable welding and cutting settings allows the machine to be finely tuned to suit different materials, thicknesses, and applications. In MIG/MAG and flux-cored modes, it supports both solid and flux-cored wires in standard sizes from 0.6 to 1.0 mm (with 0.9 mm specifically for flux-cored wire), making it well suited for mild steel, stainless steel, and gasless welding jobs. A heavy-duty 4-roller wire feed system ensures smooth, consistent wire delivery, even when working with larger wire diameters.

For DC TIG welding, the CTM-250 ST produces clean, controlled welds on carbon steel, stainless steel, copper, and brass. Adjustable functions such as gas pre-flow and post-flow, along with current upslope and downslope control, help improve arc stability and weld quality. MMA welding is further enhanced with hot start and anti-stick features, making arc ignition easier and reducing electrode sticking.

Safety and durability are built in, with VRD voltage reduction, thermal overload protection, intelligent cooling, and a rugged ST-Guard housing ensuring reliable performance in demanding environments. The integrated plasma cutter operates on compressed air and delivers up to 45 A cutting power, capable of cutting materials up to approximately 14 mm thick, depending on material type. It cuts cleanly through structural steel, stainless steel, and even painted or lightly rusted metal.

Despite its broad functionality, the CTM-250 ST remains lightweight and portable at around 12.9 kg, with a compact footprint that makes it easy to transport and store. A comprehensive accessory package—including MIG, TIG, and plasma cutting torches, hoses, and consumables—means the machine is ready to work straight out of the box.

Please note that this unit is not suitable for aluminium welding.

Functions:

• MIG/MAG welding (GMAW): Direct current metal inert gas welding for steel and stainless steel applications. Inert gases (MIG, e.g., argon) or active gases (MAG, e.g., CO2 or mixed gas 82/18 Ar/CO2) can be used. Gas and welding wire exit the torch head together, allowing even longer fillet welds to be comfortably performed with one hand. Adjustable wire diameters of 0.6 / 0.8 / 1.0 mm allow for optimal adaptation to sheet thickness and weld requirements.
• Flux/cored-wire welding (without gas): Flux welding is based on the MIG/MAG process but does not require an external shielding gas. Special flux-cored wire (e.g., 0.9 mm) generates its own shielding atmosphere through the core. The CTM-250 ST supports various wire feed rollers (U-, V-, and knurled K-profile) to process solid wire, aluminum wire, and flux-cored wire with a consistent feed rate – ideal for outdoor applications or locations without a gas cylinder.
• DC TIG welding: Tungsten inert gas welding with direct current from 20–200 A for high-quality, spatter-free welds. Suitable for unalloyed and high-alloy steels, stainless steel, copper, brass, and similar materials. Using argon 4.6 or higher as a shielding gas, along with a TIG torch with a tungsten electrode and filler rod, precise fine and visible welds can be produced. The advanced TIG menu offers features such as gas pre-flow, gas post-flow, current ramp-up, and current ramp-down to precisely control heat input and weld shape.
• MMA/SMAW (ARC): Manual metal arc welding with 20–180 A for coated stick electrodes. The process is suitable for universal use – from workshop to assembly work – and can be used without problems even in windy conditions or outdoors. Typical electrode diameters of 1.6 to 5.0 mm can be processed, covering material thicknesses from approximately 1 to over 8 mm. Hot start facilitates ignition, anti-stick reduces sticking, while VRD lowers the open-circuit voltage when the electrode is at rest.
• CUT plasma cutting with 45 A: Plasma cutting with currents of 15–45 A and compressed air (4 bar). The electric arc melts the material, the compressed air removes the molten pool, thus creating the cut. Suitable for all conductive metals such as mild steel, stainless steel, aluminum, copper, brass, or titanium, with cutting capacities up to approx. 14 mm (material-dependent). Contact ignition facilitates starting: A brief touch of the workpiece is sufficient; contact is maintained for the cutting process.
• 4-roll drive – A powerful 4-roll drive ensures a reliable wire feed that continuously and safely transports even thicker welding wires during MIG/MAG welding.
• Automatic wire feed: The welding wire is automatically pulled from the wire spool and fed through the hose assembly to the contact tip via the wire feed unit. The feed speed automatically adjusts to the set welding current, thus supporting a constant arc and uniform penetration.
• 2-stroke/4-stroke operation: In MAG and DC TIG operation, you can choose between 2-stroke and 4-stroke modes. 2-stroke is suitable for short weld spots, while 4-stroke is more convenient for longer welds, as the torch trigger does not need to be held down continuously.
• Voltage and arc correction (MIG/FLUX): The device offers an adjustable open voltage (13–28 V) as well as limited voltage and arc width correction from -5 to +5. This allows for fine-tuning of penetration, droplet size, and arc width to optimally influence weld seam and spatter formation.

Features & Benefits of the Stahlwerk CTM-250 ST

•  4-in-1 solution with integrated plasma cutter: One device covers TIG, MIG/MAG, MMA/MMA welding as well as CUT plasma cutting. This reduces investment costs, space requirements and setup times, as no device change is necessary for welding and cutting the same workpieces.
•  High power reserves in a compact design: With 20–200 A in MIG/MAG and TIG mode, 20–180 A in MMA mode, and 15–45 A for cutting, the CTM-250 ST offers ample power reserves – even for larger cross-sections. At the same time, the tool remains handy and easy to transport at only approximately 12.9 kg and 480 x 210 x 380 mm, making it ideal for mobile applications.
•  Solid duty cycle for everyday use: The duty cycle of 15% at 200 A and 60% at 100 A (MIG/TIG) as well as 15% at 45 A in CUT mode allows the use of maximum power in intervals and continuous work in the medium power range – ideal for repairs, constructions and small series.
•  Modern IGBT technology and smart cooling: The integrated IGBT power electronics ensure a stable arc, high energy efficiency, and low weight. Combined with the powerful fan and overheating protection, this enables reliable continuous operation; in case of overload, the device switches off in time and automatically reactivates after cooling.
•  Safe operation thanks to VRD, Hotstart & Anti-Stick: The VRD function reduces the open-circuit voltage in MMA operation as soon as welding is not taking place – an added safety feature when changing or setting down the electrode. Hotstart improves ignition, while Anti-Stick reduces sticking and puts less strain on the electrode and the machine.
•  Finely adjustable welding parameters for MIG/MAG & TIG: Voltage and arc width correction allow for precise adjustment of the MIG/FLUX arc, e.g., for deeper penetration or smoother weld transitions. In TIG operation, gas pre-flow, gas post-flow, current rise, and current fall are available to precisely control heat input and weld appearance – particularly helpful for thin sheets and demanding visible welds.
•  Ergonomic ST-Guard housing & intuitive control panel: The robust ST-Guard housing reliably protects the electronics while also being ergonomically designed. The clear control panel with digital display for current and voltage, process selection button, wire diameter selection, gas and mode buttons enables quick, logical setting of all parameters – even for less experienced users.
•  Flexible in terms of wire and application: By selecting different wire diameters and suitable wire guide rollers (V, K), the tool can be operated with solid, stainless steel, and flux-cored wires. This makes the Stahlwerk CTM-250 ST a universal partner for bodywork, workshop repairs, steel construction, railings, tanks, and many other applications.
•  Extensive accessories for immediate use: The scope of delivery includes fully equipped MIG, TIG, and CUT torches, gas and air connections, wire guide rollers, contact tips, and other accessories. This allows the unit to be used immediately after connecting electricity, gas, and compressed air, without the need to retrofit additional basic components.

Operating instructions : The CTM-250 ST is not suitable for welding aluminum.

Stahlwerk CTM-250 ST Combination Welding Machine comes with the following:

• 1 x STAHLWERK CTM-250 ST combination welding machine
• 1 x Professional TIG welding torch WP-26F, hose package 3 m
• 1 x TIG/WIG accessory set, 8 pieces
• 1 x professional plasma hose package AG-60/SG-55, 3 m
• 1 x Plasma accessory set, 4 pieces
• 1 x water separator with pressure gauge and snap-on quick couplings (male/female)
• 1 x connecting hose with snap-on quick couplings from the device to the water separator
• 1 x Professional MIG welding torch AK-15, hose package 3 m with Euro central connection
• 1 x MIG accessory set, 3-piece (pre-assembled): gas nozzle, 0.8 mm contact nozzle, gas nozzle holder
• 1 x ground cable 3 m
• 1 x Electrode clamp 3 m
• 1 x wire brush
• 1 x gas connection hose with quick coupling 5 m
• 1 x contact tip M6 x 28 – Ø 1.0 mm
• 1 x contact tip M6 x 28 – Ø 0.8 mm
• 2 x wire guide roller 0.6 & 0.8 mm with V-profile
• 1 x wire guide roller 0.8 & 1.0 mm with V-profile (pre-assembled)
• 2 x wire guide roller 0.8 & 0.9 – specially for flux-cored wire (knurled)
• 1 x Allen key
• 1 x Mounting wrench
• 1 x protective case