What Does IPM Stand for in Welding?

what-does-ipm-stand-for-in-welding

Have you ever wondered what does IPM stand for in welding? Well, every welder wants to be efficient in their work; the goal is to produce large quantities of high-quality welds in less time. However, how effectively this can happen depends on the welder’s skill and IPM.

What does IPM stand for in welding? IPM in welding stands for “inches per minute.” It is a measure of travel speed and can be an aid for professional welders to benchmark their welding skills as well as improve weld production.

Since IPM is a measuring medium, welders need to understand it. The remainder of this article includes an introduction to IPM, its importance, and factors related to IPM.

Introduction to IPM

As mentioned earlier, the IPM, or “inches per minute” measures travel speed, or the metal covering rate. It is determined by considering the production of welds between metallic materials within a minute.

Other welding measurements may be employed, but the IPM system is the standard method of measuring welding speed and is generally accepted among professional welders.

How to Calculate IPM

To calculate IPM:

1.) complete the weld for a pair of metals;

2.) make sure to time yourself from when you begin the weld.

3.) use a measuring tape to check the length of your work in inches.

4.) divide your final measurement by the amount of time it took you to create the weld (in minutes). The number you get is the number of inches you welded within a minute or your IPM.

Examples:

  • 15 inches of weld / 3 minutes = 5 IPM
  • 22 inches of weld / 4.5 minutes = 4.8 IPM
  • 40 inches of weld / 10 minutes = 4 IPM
  • 72 inches of weld / 12 minutes = 6 IPM

The more you can weld in less time, the higher your IPM is.

Effects of IPM in Welding

Many factors can affect your IPM, including the welding method, materials, and more.

Cushion Effect & Penetration

IPM is used to aid the welding process, and overall production of welds; how low or high the IPM is can affect how well a weld is done, especially when it comes to the penetration of the base material.

For example, a slow IPM or travel speed will create more metallic build-up while trying to reach the deepest part of a metal. The resulting obstacle is known as a cushion effect; it creates a type of weld that is not dependent on the penetration of the base material.

On the other hand, a fast IPM or travel speed allows the welder to reach the deepest part of the metal; this leads to the penetration of the base material and creates a different type of weld (EWI).

With that said, a welder must be conscious of the type of weld they want to produce and adjust their IPM accordingly to achieve it.

IPM & Different Materials

Changes in IPM will vary across different welding materials. For example, the travel speed for tube mill welding should be 3 to 60 IPM; welding the tube with the incorrect speed may cause some damage to the material. This is because some metals require a little time to cool down before the welding process continues—a high IPM will prevent that.

Likewise, the assigned Inch per meter – IPM- for other materials used for lathe welding is 5 to 60 IPM, while orbital welding is 4 to 10 IPM.

Overall Welding Activities

Travel speed limits some welding activities. For example, heavy-duty projects must be performed at a relatively slow speed; if the IPM increases more than necessary, the inner core of the base metal will not weld perfectly and may result in damage. On the other hand, heavy metal can be melted firmly by applying slow IPM procedures.

As a slow IPM increases the durability and chance to create a perfect bond, the productivity decreases since the IPM essentially slows down the net production time.

An incorrect IPM measurement may cause complete damage, especially in the materials that have low heat capacity.

For example, the same welding voltage cannot be used for pure iron and some metalloids because their heat capacity varies. Otherwise, the heat may cause permanent damage.

IPM-measurement

Factors that Determine IPM

Various factors determine the appropriate IPM for a weld and, therefore, the rate of production.

Materials Used

Sometimes, the nature of the material will dictate the speed. For example, the amount of heat used for welding an aluminum material will be different from using copper. These variables will determine heat capacity, and therefore IPM required to produce a good weld.

Types of Welding Processes

There are many forms of welding, and they can differ from the nature of materials used as well as the medium used for welding. Some types of welding processes are advanced and require high heat, while others can be done with very little heat.

Other elements within each welding form can directly determine the travel speed or IPM required for specific welds.

Some welding processes may require a higher IPM than others, depending on:

  • Electrode size
  • Type of shielding
  • Welding voltage
  • Amps settings
  • Voltage settings
  • Groove configuration
  • Groove fit-up uniformity
  • Welding position

Applications of IPM in Different Types of Welding

The following are some common welding processes and how IPM is used for each:

1. Flux-Cored Arc Welding

Arc welding is often used in heavy welding; most heavy welding requires slow speeds because the core of the metals must be heated up. Otherwise, the structure of the design will be weak and may cause future complications.

However, flux-cored arc welding uses the high-heat (amps/volts settings) method of welding; this may increase productivity concerning IPM, but most heavy welding work requires low IPM for better performance.

 2. TIG Welding

This welding requires little or no filler metals, and it does not use the electrode. There is no spatter; thus, this is a common type of welding for experts. If a new welder performs this type of welding process, the wrong IPM can greatly affect the final weld’s quality.

3. Shielded-Metal Arc Welding

Stick welding is one of the most straightforward welding processes because it requires a simple electrode stick, and the process involves an anti-oxidation state. The stick has a coat that aids in the production of smooth welds.

The travel speed (IPM) required for this type of welding is usually very high. It can also be used with almost all metallic materials, even rusted parts.

4. Metal Gas Inert Welding (MIG)

The type of welding is versatile and is used for different materials of various thicknesses. It involves the oxidative process and is mostly performed indoors. The depth of the material used for welding mainly determines the IPM.

The melting process involves different levels of IPM, based on the materials used in the process. The welder performing the work should determine the appropriate travel speed accordingly. Regardless of if the IPM is at a slow or fast rate, the results are usually favorable, unlike flux-core welding.

Conclusion

Inches per meter, or IPM, is the simplest means of measuring welding travel speed. It is a generally accepted measure for welders around the world to determine how much of a weld should be produced within a short period to ensure the final seam ends up clean and without fault.

Many factors determine the best IPM for a project. Still, the welder ultimately gets to decide which IPM is most appropriate according to the materials they’re using and the welding process they plan on applying. With the right IPM, welders can produce many high-quality welds in a short amount of time.

References:

longevity-inc.com/welding-articles/post/arc-length-weld-speed-and-welding-current

ewi.org/gas-metal-arc-welding-basics-travel-speed-and-contact-to-work-distance-ctwd/

twi-global.com/technical-knowledge/faqs/what-is-welding

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David Harper

David is the Co-Founder and Senior Editor at weldingtroop.com. David's an experienced fitter and tuner/welder who's passionate about helping others develop in life through new skills and opportunities.

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