Welding Parameters Explained

Learning how to weld is a continuous process rooted in the understanding of the foundation of each welding process and your machine. The challenge is that welding technology is in a constant state of evolution, introducing new features that revolutionize the convenience and specialization of welding.

Mastering the welding parameters is not just a technical skill; it's a key to unlocking your welding potential. In this article, we'll delve into the basic and process-specific welding parameters, equipping you with the knowledge and confidence to tackle any welding project.

5 Basic Welding Parameters

All welding parameters can be divided into two groups:

• Basic Welding parameters
• Process-specific welding parameters.

We will first focus on the basic welding parameters that remain the same regardless of the welding process. These five basic welding parameters are denoted by the acronym CLAMS, and they represent:

• Current
• Length of the arc
• Angle of the arc
• Manipulation of the torch
• Speed of welding

Welding Current

The welding Current or the amperage dictates the size and penetration of a weld. This parameter is often known as the heat. As you increase the current, you get higher heat and, therefore, the size and penetration of your weld.

Setting the welding current will depend on the thickness of the base metal. The thicker the metal is, the more heat you'll need to melt it and fuse the pieces and avoid the defect known as lack of fusion or penetration. However, over-tuning the amperage can cause burn-through on thinner pieces.

Length Of The Arc

The arc Length is the distance between the top of the electrode and the welding joint. In the world of welding, this parameter is also known as the voltage, and in most processes, you adjust it by moving the torch closer or further to the welding joint.

The voltage affects the amount of current that is transferred into the welding joint. Adjusting the voltage is based on the other parameters and welding processes. For example, in stick welding, the length of the arc is the same as the electrode diameter. In MIG welding, the length is longer and based on a wire stickout.

Failing to adjust the length of the arc can also cause several defects. Low voltage creates an unstable arc with lots of spatter. High arc length produces inconsistent penetration and a turbulent weld pool.

Angle of the Torch

The Angle of the torch is defined by two parameters - work angle and travel angle.

The work angle shows the relationship between the joint and the electrode. When welding in a flat position, the electrode is perpendicular to the base pieces and placed at 90 degrees. In Tee-Joint or fillet welds, where pieces are joined at 90 degrees, the work angle is approximately 45 degrees.

The travel angle is the angle at which your torch is pointed as you move across the joint. In most situations, you will need a 5-15-degree travel angle to produce the solid welds.

Source: http://www.halversoncts.com/910-welding-joints-in-the-horizontal-welding-position.html

Manipulation Of The Torch

The way you move your torch across the joint can also affect how your weld turns out. There are two primary types of torch movement - straight and side-to-side.

Straight torch movement produces stringer beads that are used on thin and medium-thickness metal to avoid creating a wide heat-affected zone (HAZ). Moving the torch side-to-side results in weaving welding beads that are used to fill larger gaps and joints.

Speed Of Welding

Welding Speed is a parameter that shows how fast you are going across the joint. The goal is to find a perfect and consistent speed that provides enough penetration without burning through the pieces.

In some applications, like uphill welding or welding thin metals, you need to go faster to avoid burn-through or molten metal slipping from the joint. When welding thicker pieces, you can go slower to provide enough heat to the joint.

Process-specific Welding Parameters And Features

The previous parameters were something you can adjust regardless of the welding process you are using, and they are the foundation of every weld. However, some process-specific features and parameters can make your welding highly convenient and easy, so let's explore them.

MIG Welding Parameters

MIG welding is one of the most straightforward welding methods due to its ease of use, as well as some of the features and parameters. However, there are also parameters for more advanced users, so we'll cover most of them.

The essential MIG welding parameters are:

Wire Feed Speed (ipm): MIG welding uses an automatically fed MIG wire that serves as both electrode and filler metal. A wire-feeding mechanism feeds the wire at the rate known as wire feed speed (WFS), which is measured in IPM (inches per minute). This parameter directly affects the welding current, so instead of typical amperage, you set the WFS in MIG welding.

Adjusting MIG Wire Feed Speed (IPM)

Voltage (V): In MIG Welding, you manually set the voltage, which determines the height and width of the bead. The key is to find a sweet spot that produces a good arc start and uniform weld bead without too much spatter.

Synergic MIG (on/off): The auto-set or synergic MIG is a feature/parameter that is the best friend of any beginner. Once you turn it on, you select the thickness of the metal and wire and shielding gas choice, and the machine automatically adjusts the wire feed speed and voltage. This is particularly helpful if you are a new welder trying to figure out how to work out the machine settings. Some advanced synergic options automatically sense the voltage fluctuation and regulate the current to keep the arc going.

2T/4T: Using two touches (2T) or four touches (4T) to start and end the weld can make the difference if you are running longer MIG Welds. 2T is your default parameter, which you press the trigger and hold as you weld. Once you release it, the arc stops. 4T includes pressing and releasing the trigger to start and pressing and releasing the trigger to stop the torch (four touches.) The pro of 4T is that you don't have to hold the torch trigger as you weld, which can significantly reduce hand fatigue when running long beads.

Dual Pulse MIG Welding with FIRSTESS DP200 on 2T Mode

Source: https://www.youtube.com/watch?v=kprEOvHJSRM

Pre-gas flow (sec): Some MIG welders will allow you to set the pre and post-gas flow. Pre-flow is quite helpful when you need to ensure cleanliness on metals such as aluminum. When pre-flow is on, your gas starts before the arc to prevent the electrode or arc from atmospheric contamination at the start of the weld.

Post-gas flow (sec): Post-gas flow ensures your shielding gas runs for a few seconds after you finish the weld. While this parameter increases the shielding gas consumption, it will protect your weld after you stop welding and cool down the torch and its consumables after the welding to prolong their lifespan.

Inductance (%): The ability to set inductance on MIG welders is typically reserved for more expensive welders, but it can be beneficial when using the short-circuit transfer. This parameter adjusts the time required for an arc to reach the base amperage. In short circuit transfer, once the wire touches the base metal, it short-circuits itself and starts spitting. Its voltage drops to 0, so the arc can reach the base amperage immediately. This is not always wanted as too high a burst of amperage can burn through delicate pieces or have adverse effects on heat-sensitive metals. By adding inductance in 0-100% intervals, you extend the period from touching the base metal to reaching the base amps.

Inductance Impacts on MIG Welding

Start Slope: The start slope is similar to inductance, as it allows you to get a gradual increase in welding current from start amps to base amps. However, this setting can be used regardless of the transfer mode and in conjunction with the end current and end slope.

Creep Start (on/off): The creep start is often used during high-speed welding, and it defines the wire feed speed before the welding arc ignites. When turned on, it slows down the welding speed before the arc is initiated to prevent unnecessary waste or accidental wire feeding, and it boosts the speed once the arc is initiated.

Crater Fill (on/off): Many welders struggle to finish the weld properly, and going fast out of the joint can create a defect known as a crater. Some advanced MIG welders will allow you to use the Carter fill feature to automatically reduce voltage and wire feed speed at the end of the weld and to enable you to appropriately fill the weld joint without burning through its end or leaving a crater. In this option, you can control the end current and end slope.

End Current (%)/Crater Slope (sec): These are advanced crater fill options that will allow you to adjust the rate of the end current and the downslope time. The end current is set in percentage of the base current, and the crater slope adjusts the duration of a gradual decrease from base to end current. The goal is, once again, to gradually reduce the current to help you fill the joint and avoid burn-through.

Burnback (%): In MIG welding, there is an issue known as burnback, and this occurs once the wire burns all the way to the nozzle and fuses or clogs it. Some MIG welders will allow you to adjust the burnback rate of the MIG wire. As the arc stops, the welding wire retracts back into the welding gun, preventing it from sticking to the workpiece, creating a ball at the end, or burning back into the MIG nozzle.

What is Burn Back

MIG Pulse (on/off): In recent years, we have seen an increased number of pulsed MIG welders. The pulse feature in the MIG welder oscillates the current between the background and peak amperage to reduce the heat input, which is crucial for delicate metals such as aluminum. However, the MIG pulse is much more complex than the TIG pulse due to the relation between wire feed speed, voltage, and current oscillation. Therefore, most new machines have a synergic pulse that automatically adjusts all the parameters, and you can turn it on or off.

Dual Pulse/Pulse On Pulse (on/off): MIG welders go even further by introducing another pulse on top of the primary pulse. The primary pulse oscillates, while the secondary pulse turns the primary pulse on and off. Besides heat control, double pulse produces highly aesthetic results, allowing you to get the "stacked dimes" weld bead with your MIG welder. Once you turn the double pulse on, you can control the parameters such as the frequency, background amps, and pulse duty cycle.

Dual Pulse MIG Frequency (Hz): Like with TIG welding, advanced machines will allow you to set the MIG pulse frequency. Fundamentally, the frequency setting shows how fast or slow you want the pulses to be. For example, 1 Hz means one pulse per second, so the pulsing completes in one second. 2 Hz means two pulses per second, so one pulse will take 0.5 seconds to complete. Frequency in MIG typically uses lower values of 0-5 Hz from slow to fast pulses.

Dual Pulse Background Amp (% or Amp): The background amp parameter in dual pulse MIG sets the lower amp perimeter in percentage of the base current. For example, if the base current is 100 amps, and you set background amps to 50%, the current will oscillate from 100 amps to 50% of the base value or 50 amps in one pulse. Some machines like YesWelder newest machine the Firstess DP200 equipped with DualPulse™ make it even easier, so you can set your background current directly in amps.

YesWelder Firstess DP200 DualPulse™ MIG Welder

Dual Pulse Duty Cycle (%): The dual pulse percentage cycle or duty cycle sets the proportion of time that the pulse spends in peak or background current. The default value is 50%, meaning the pulse spends an equal amount of time in base and background amps, but you can modify that. For example, a 30% cycle means the current spends 30% on base amps and 70% on background amps. 60% cycle means the current spends 60% of the time on base amps and 40% of the time on background amps.

Spot Timer (sec): Some MIG welders designed for sheet metal welding can have a built-in spot timer. A spot timer will allow you to make repetitive spot welds across the joint to make sure the sheets are well-aligned and fit.

TIG Welding Parameters

TIG Welding is considered one of the high-skill/high-rewards welding methods. One thing that makes this possible is the enormous amount of welding parameters you can set up and control. Modern TIG welders allow you to control the current from the start to the end of the weld and provide some features that make it widely used in most critical applications.

The most common TIG welding parameters are:

(Base) Amperage (A): On a TIG welder, instead of wire feed speed, the welding current is set by adjusting the amperage, and this is the most basic setting. Amperage can further be set by starting amps, peak amps, and end amps.

Pre-flow (sec): Like with the MIG welder, your gas flow can start before the arc. This provides a protective environment for the arc, which is crucial for sensitive materials.

Starting Amperage (A): Some heat-sensitive metals dislike the sudden burst of heat, so instead, you can set the lower starting amperage to heat and melt the pieces gradually.

Upslope: Instead of going from starting to base amperage immediately, you can set up the upslope or ramp-up rate. The welder then gradually reaches the base amps. A gradual increase of current will reduce the heat stress on the base piece.

What is Upslope?

Downslope: After reaching the base amperage, you weld and come close to finishing the weld. To fill the crater and smoothly finish the weld, you can set up the slope down or ramp down rate. Instead of arc extinguishing immediately, the amperage now gradually goes down to the end amps.

End Amps (A): End amps will once again help you fill the entire weld joint and avoid creating a crater at the end of the weld. By using lower amps, you provide enough heat to solidify and finish the weld but not too much amperage to burn through the end of the weld.

Post Flow (sec): Post-shielding gas flow will provide enough protection once you finish the weld and cool down your torch to extend the consumable lifespan.

2T/4T: The 2T/4T mode in TIG welding is more complex compared to MIG. While the two touches are virtually the same, 4T controls all the parameters above. The first press and release start the pre-flow and go from starting amps to ramp-up. Once you release the trigger, you are on your base amps and welding. The second press and release initiate the ramp down, end amps, and post-weld gas cooling, with a total of 4 touches.

AC Frequency (Hz): Regular households and basic TIG welders use an Alternating Current at the frequency of 50-60 Hz, meaning that the current switches from EP to EN 50-60 times per second. However, new GTAW inverters allow you to adjust frequency anywhere from 20 to 400 Hz. Frequencies between 80 and 120 Hz increase arc control and welding speed, while 120 to 200 Hz are suitable for most aluminum welding.

AC Balance (%): TIG welding is one of the few processes that can successfully use the Alternating Current. In AC, the current oscillates between the positive (DCEP) and negative (DCEN) sides of the terminal to provide enough cleaning action and penetration. AC is critical when welding aluminum or other metals with an oxide layer on top, and some welders will allow you to set the AC Balance. By default, the current spends an equal amount of time at both polarities. Still, the balance can help you get more cleaning action or more penetration if needed (more time spent or positive or negative polarity.)

AC Balance in TIG Welding
Source: https://www.weldpundit.com/ac-balance-in-tig-welding/

AC Base Amps (A): Advanced TIG welders will allow you to independently select the base amps of both EN and EP polarities. Using different values will allow you to direct more heat away from the electrode and into the base metal. If you are not using this feature, then the current oscillates between the AC base amps.

AC Waveform (Sine wave, Square wave, Triangular wave): The AC waveform dictates how the current oscillates from EP to EN. This can be done in several forms, such as sine wave, square wave, or triangular wave, and each changes the arc and puddle characteristics. The sine wave is a default choice that offers a soft arc with the feel of a conventional power source. In square wave AC, the voltage is a constant positive value for half of the period and a constant negative value for the other half of the period. A triangular wave reduces the distortion of the parts and allows a fast solidification of the welding pool.

Source: https://www.eeweb.com/the-basic-quantities-of-ac-waveform/

TIG Pulse Parameters: The TIG welding pulse is highly advanced, and although the concept of switching between peak and background amps is the same, you can set the frequency, pulse width, precise base, and background amps. Frequency (Hz) adjusts how many pulses per second you get. Pulse width (%) shows the percentage of the timeframe when the peak amperage is active. Background (%) and base amps (A) are standard.

TIG Arc Starts (HF/Lift/Scratch): In TIG welding, there are several ways to start the arc, and you can see the options on your welder. HF means high-frequency, and this is a go-to, cleanest, and non-contact start method. Lift TIG is next in line for cleanliness, but you have to briefly touch the base metal with tungsten and lift the torch to start an arc. Scratch start is the oldest method, where you scratch the surface to start the arc, but due to possible contamination, it is scarce today.

Spot Timer/Cold Spot: A TIG welder spot timer can also be used to make repetitive TIG spot welds on sheet metal, like with MIG. However, Some TIG welders also offer Cold Spot options.

These are very tiny spots with limited HAZ and heat used on delicate metals.

Stick Welding Parameters And Features

Stick welding is the most straightforward procedure in terms of parameters and features. Most stick welders have a single knob and only several things to adjust.

The most common Stick welding parameters and features are:

Amperage (A): Like with other processes, amperage is the most fundamental parameter, and there are no shenanigans like with TIG welding in terms of low or high amps. You set the amperage, and the machine keeps it consistent throughout the operation.

Hot Start (%): Unlike TIG welding, where you use lower amps and then gradually increase the heat, Stick welding uses a parameter known as hot start. A hot start provides a burst of higher current at the start of the welding, which is measured in percentages of base amps. Welders use hot start with some electrodes that require a high initial current to start the arc but then lower amps to run to avoid burn-through.

Anti-stick (on/off): Unlike its name, the anti-stick feature won't help you prevent electrodes from sticking to the base metal. Sticking is avoided by proper CLAMS, and this feature will help you remove the electrodes if they stick. As the electrode sticks, it short-circuits itself to the base metal. The more time it spends stuck, the higher current runs through it, eventually completely fusing it to the base metal. With the anti-stick, the machine senses that the electrode starts short-circuiting and immediately kills the current and voltage to allow you to remove it from the surface quickly.

Arc Force (Dig): The arc force or Dig is the parameter that helps welder and inverter components deal with voltage fluctuations. When this feature is on, the machine senses the voltage changes and boosts or reduces the current to keep the arc going. This is essential when working with notorious E6010s or other aggressive electrodes.

VRD (on/off): A Voltage Reduction Device (VRD) is a safety feature that reduces the open circuit voltage (OCV) when you are not welding. Electrodes often require high OCV to initiate an arc, but this high voltage can cause shocks if you are not careful. If on, your VRD reduces the OCV before you start your weld. Once you try to initiate the arc, the machine senses resistance and increases the open circuit voltage. Once you are done, the resistance stops, and the device reduces the OCV.

Final Thoughts

While the list of parameters you need to know is not that short, understanding how each can help you during your welding project is crucial. Sometimes, small things can make or break your weld, and having the right tools in your arsenal but not using them is just a waste.

Besides the basic welding parameters, which are crucial in creating a sound weld, process-specific parameters can make your welding much more convenient and easy. Therefore, there is no reason to learn and use any of the features and parameters we discussed today.

👏 You may be interested in the following:

• Pulsed MIG Welding Tips And Techniques
• TIG Welding Technique: Walking The Cup Explained
• Is Welding a Good Career, And Should You Pursue It?