Modern TIG welders often include a pulse function, but many welders are unsure whether they should use it or simply weld with a constant amperage.

Pulse TIG can improve heat control, weld appearance and penetration when used correctly. However, it is not always the best choice for every application and can sometimes slow down productivity if incorrectly applied.

In this guide, we’ll explain exactly what TIG pulse welding does, the advantages and disadvantages, and when you should consider using it.

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What Is TIG Pulse Welding?

Pulse TIG welding alternates between two current levels:

• Peak Current
• Background Current

Instead of maintaining a constant welding current, the machine rapidly switches between the two amperage levels.

For example:

• Peak Current: 120A
• Background Current: 40A

The peak current provides penetration and fusion while the background current allows the weld pool to cool slightly before the next pulse.

This repeated cycle helps reduce overall heat input while maintaining weld quality.

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Understanding Pulse Settings

Most TIG welders allow adjustment of three main pulse parameters.

Pulse Frequency (Pulses Per Second)

Measured in Hz (Hertz).

Examples:

• 0.5 Hz = one pulse every two seconds
• 1 Hz = one pulse per second
• 10 Hz = ten pulses per second
• 100 Hz = one hundred pulses per second

Low pulse frequencies create a visible pulsing effect.

Higher frequencies tighten and focus the arc.

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Peak Current

The highest current reached during each pulse cycle.

This provides:

• Penetration
• Fusion
• Weld pool formation

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Background Current

The lower current maintained between pulses.

Typically set between:

• 20%
• 50%
• 70%

of peak current.

This helps maintain the arc while reducing overall heat input.

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Pulse Duty Cycle

Controls how long the machine remains at peak current versus background current.

Example:

50% Duty Cycle

• 50% peak current
• 50% background current

Higher duty cycles increase heat input.

Lower duty cycles reduce heat input.

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Advantages of Pulse TIG Welding

Better Heat Control

This is the biggest advantage of pulse TIG.

Because the current constantly drops between pulses, the weld receives less overall heat than a constant amperage weld.

Benefits include:

• Less distortion
• Reduced burn-through
• Better control on thin materials

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Easier Thin Material Welding

Pulse TIG is extremely useful when welding:

• Thin stainless steel
• Thin aluminium
• Sheet metal
• Tube work

The reduced heat input makes it easier to prevent warping and burn-through.

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Improved Weld Appearance

Many welders use low-frequency pulse settings to create evenly spaced weld ripples.

Typical settings:

• 1-2 Hz
• Peak current set normally
• Background current 30-50%

This can produce the classic “stack of dimes” appearance.

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Reduced Distortion

Heat distortion can be a major problem when welding:

• Stainless steel
• Aluminium sheet
• Thin fabrication work

Pulse TIG helps reduce total heat input and therefore minimises distortion.

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Better Control Around Edges

When approaching:

• Corners
• Edges
• Thin sections

Pulse allows the weld pool to cool slightly between pulses, reducing the chance of melting away the edge.

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Improved Positional Welding

Some welders find pulse helpful when welding:

• Vertical joints
• Overhead joints
• Pipe work

The cooling period between pulses can make the weld pool easier to control.

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Reduced Risk of Overheating Stainless Steel

Excessive heat can cause:

• Discolouration
• Distortion
• Reduced corrosion resistance

Pulse TIG can help keep temperatures lower while maintaining penetration.

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Disadvantages of Pulse TIG Welding

Slower Welding Speed

Pulse settings can encourage a slower travel speed.

For some production work, welding with a steady current may be faster.

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More Complex Setup

A standard TIG setup requires only amperage adjustment.

Pulse introduces additional variables:

• Frequency
• Duty cycle
• Background current

Incorrect settings can actually make welding harder.

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Not Always Necessary

Many experienced TIG welders rarely use pulse.

For:

• Thick material
• General fabrication
• Structural work

A properly controlled constant current weld often works perfectly well.

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Can Reduce Productivity

In production environments, additional setup time may outweigh any benefits gained from pulse.

If heat input is not a concern, straight TIG welding may be more efficient.

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High Frequency Pulse Takes Practice

Very high pulse settings:

• 50 Hz
• 100 Hz
• 200 Hz

can significantly alter arc behaviour.

These settings often require experience to use effectively.

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Low Frequency vs High Frequency Pulse

Low Frequency Pulse (0.5 – 5 Hz)

Best for:

• Manual TIG welding
• Decorative welds
• Thin stainless steel
• Pipe welding

Benefits:

• Visible weld rhythm
• Improved appearance
• Better heat control

Many welders use 1-2 Hz as a starting point.

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Medium Frequency Pulse (5 – 30 Hz)

Best for:

• General fabrication
• Improved arc control
• Stainless steel work

Benefits:

• Smoother arc
• Better weld pool control
• Reduced heat input

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High Frequency Pulse (30 – 250 Hz+)

Best for:

• Aerospace applications
• Precision fabrication
• Thin materials
• Specialist work

Benefits:

• Narrow arc profile
• Increased arc focus
• Excellent control

Higher frequencies are generally used by more experienced operators.

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Pulse TIG Settings Starting Points

Stainless Steel Sheet

Material:

1.5mm Stainless Steel

Suggested Settings:

• Peak Current: 70A
• Background Current: 35A
• Frequency: 1-2 Hz
• Duty Cycle: 50%

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Aluminium Sheet

Material:

2mm Aluminium

Suggested Settings:

• Peak Current: 110A
• Background Current: 50A
• Frequency: 1-2 Hz
• Duty Cycle: 50%

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Stainless Tube

Material:

2mm Stainless Tube

Suggested Settings:

• Peak Current: 80A
• Background Current: 40A
• Frequency: 1-3 Hz
• Duty Cycle: 50%

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When Should You Use Pulse TIG?

Pulse TIG is worth considering when:

✓ Welding thin material

✓ Distortion is a concern

✓ Welding stainless steel

✓ Welding aluminium sheet

✓ Looking for improved weld appearance

✓ Positional welding

✓ Pipe welding

✓ Learning better weld pool control

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When Should You Turn Pulse Off?

Pulse is often unnecessary when:

✓ Welding thick material

✓ General fabrication work

✓ Production welding

✓ Maximum travel speed is required

✓ Heat input is not an issue

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Pulse TIG on Modern Welding Machines

Many modern machines from manufacturers such as:

• Jasic
• Fronius
• EWM
• ESAB
• Lincoln Electric
• Miller

offer advanced pulse functions with adjustable:

• Peak current
• Background current
• Pulse frequency
• Duty cycle

Some premium machines can pulse at several thousand pulses per second for specialist applications.

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Final Thoughts

Pulse TIG is a powerful feature that gives welders greater control over heat input, penetration and weld appearance.

For thin stainless steel, aluminium and precision fabrication work, pulse can significantly improve results and reduce distortion.

However, pulse is not a magic setting. For many everyday welding jobs, a properly adjusted constant amperage weld can perform just as well while allowing faster travel speeds.

The key is understanding when pulse provides an advantage and adjusting the settings to suit the material, thickness and application.

At WeldAssist, we recommend experimenting with pulse on scrap material first to understand how frequency, background current and duty cycle affect the weld before using it on critical jobs.