MMA Welders For Sale - Stick Welding Sorted
The range of MMA welders for sale at Weldtech are designed to provide a reliable current for welding steel and other metals with a consumable flux coated electrode. The key characteristic of an MMA welder is that it will provide a steady DC electric current which remains constant even if the welder’s movements cause voltage and arc length to vary. This helps to keep the metal temperature nearly constant to maintain the uniformity of the welding bead.
MMA Inverter Welder Setup
The usual arrangement in an MMA welding process is:
- The welder (usually an inverter power supply like the ESAB Buddy Arc 180
- A ground clamp
- A consumable electrode of the welding metal coated in flux
- An electrode holder designed to make a good electrical connection to the metal core of the electrode
- A pair of very heavy duty leads to complete the circuit. Currents used in MMA welding are typically in the 60 to 300 Amp range
The consumable welding supplies for this process are the MMA electrodes, which can be anywhere in the range of 2.5 – 5.0mm in diameter. The size and composition chosen, depends on the nature of the welding task and the power available from the arc welder inverter circuitry.
A good MMA DC inverter welder will nowadays have a digital display of the all the parameters relevant to the duty cycle of this process. Its very simplicity and dependance on the welder's skills mean that weld quality cannot be taken for granted.
MMA Welder Definition
MMA is called Manual Metal Arc welding in the UK, while in the USA it’s referred to as SMAW or Shielded Metal Arc Welding. Most commonly, in day to day use welders will just refer to it as stick welding! This is closest to the original form of arc welding as developed in Russia in the 1880s and refined with a flux protective coating for the electrodes, in the UK, in the early 20th century. MMA welding is typically used for fabrication of steel structures and workshop repairs in carbon steel, alloy steels, stainless steel, nickel copper and occasionally aluminium. More info on MMA welding processes.
During the welding process, the arc has to be initiated with a hot start. The electric arc is started by making contact between the electrode and the workpiece to get current flowing, as the, typically, 200 amp current flows into the workpiece; it and the electrode rapidly heat up. The welder then withdraws the electrode from the workpiece surface to initiate the arc and ramp up the temperature to the melting point of the steel being welded. This releases droplets of molten metal from the electrode and melts the surfaces of the workpiece(s). MMA arc welding machines have to supply a constant level of current even as the welder moves and even the most skillful stick welder will cause challenges to a low cost MMA machine.
As the arc heats up, the flux melts as well and gives off gases that protect the weld from atmospheric nitrogen and oxygen as well as creating a liquid slag that quickly coats the cooling weld as the weld pool is moved down the job.