Stronger welds. Longer life. Lower cost.
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Increase fatigue life by decades.
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Reduce maintenance and repair costs.
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Stronger welds — even in existing structures.
Weld-Hit HFMI Package
Everything is included
- HFMI Hammer - Made in Europe
- Air treatment unit for lubrication and adjustment of treatment intensity, mounted on a flexible magnetic foot
- Wear pins ranging from 1,5 to 4 mm in radius
- Quality gauges to control the treatment depth
- High-quality heat-resistant hose with CEJN esafe safety couplings
Everything is packed and stored in a durable case, ready to follow you to your next weld job, with a total weight of only 6 kg.
Our equipment operates using compressed air, 2-6 bar, delivering impacts at approximately 100 Hz to the weld toe, creating a precise groove with a radius typically ranging from 1.5 to 2.0 mm. Through this process, compressive stresses are induced, significantly enhancing the fatigue life of the treated weld toe.
Adjust the air pressure to suit the steel grade and working conditions, ensuring an optimal working environment and process control. The HFMI hammer features recoil damping and a noise-reducing exhaust coil, maintaining a low vibration value for this equipment type.
Despite its robust capabilities, the machine retains a compact size, weighing just 1.3 kg.
Why use the Weld-Hit HFMI tool
Extended fatigue life of new and existing structures
- Treat the weld toe to improve the fatigue properties, typically 3-10 times.
- Introduce compressive stresses in the weld toe – reduce crack initiation and propagation.
- Improve geometry – by creating a radius of 1.5-2 mm, the stress concentration is reduced. Radius 2 gives better improvement.
- Avoid design changes.
- Increase load capacity and/or life on existing structure/designs.
- Give the possibility to reduce plate thickness.
- Enable the usage of high-strength steel.
- Use for preventive maintenance, since HFMI can reset the fatigue life of a weld toe. Even with a ~1 mm crack, it is possible to add critical points to maintenance schedules.
Superior quality of weld repairs with Interrun peening
When a weld cools, it contracts. This creates tensile residual stresses close to the yield strength, as well as distortions. Both distortion and residual stresses mean that the risk of new cracks and failures remains high, even if the welding work is carried out perfectly. Interpass peening is particularly effective in thick and rigid structures with high restraint. By treating and forming the weld surface between each pass, compressive stresses are introduced, allowing deformation to be controlled and eliminating the need for straightening. This is illustrated in the image below.
The method is especially valuable in applications where downtime for repairs is unacceptable or extremely costly, such as in process industries and mining. However, it is useful everywhere when the goal is to extend the life of older steel structures without requiring repairs until they reach the end of their lifespan.
The equipment can also be used for repairing difficult‑to‑weld materials. ESAB’s repair handbook, for example, recommends using a peening hammer — “Work the weld surface with a peening hammer (manually) immediately after welding.”
Perhaps the time has come to replace the manual peening hammer and take advantage of the improvement also for weld repairs in weldable materials.
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New Web-Shop!
European company customers can now buy our standard HFMI kit directly in our shop
Weld-Hit application areas
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About Weld-Hit
Weld‑Hit AB is a Swedish, knowledge‑driven family company specializing in HFMI technology that strengthens welded structures and extends their service life. We provide modern, reliable, and easy‑to‑use HFMI solutions that help welders and industries improve fatigue performance, increase safety, and reduce long‑term maintenance costs.
Weld‑Hit was founded in 2017 by Erik Åstrand, a Swedish engineer with a deep passion for weld quality, structural integrity, and practical innovation. With long experience in fatigue‑critical industries and a strong commitment to accessible engineering solutions. After PhD studies, Erik saw the need for HFMI technology that was easier to use, more affordable, and available to every welder.
Driven by curiosity, hands‑on problem‑solving, and a belief that stronger welds create better and more sustainable structures, Erik built Weld‑Hit as a family company focused on knowledge, reliability, and real‑world results.
Weld‑Hit aims to empower the next generation of steel construction by making it possible to use thinner, stronger, and more efficient high‑strength steels in new designs. Through accessible and reliable HFMI technology, we enable engineers and manufacturers to push the boundaries of lightweight construction without compromising safety or durability.
At the same time, our vision includes giving existing structures a longer and more sustainable life. By providing repair and enhancement procedures that create welds stronger than the original, we help extend the service life of bridges, machinery, and critical infrastructure. This reduces material consumption, lowers environmental impact, and supports a more resource‑efficient future.
Weld‑Hit strives to be a driving force in a world where smarter design, longer lifespans, and better weld quality go hand in hand.
Links and references
IIW - Recommenations
2nd edition 2025
WQMS - Australian partner
Our Australian partner. Specialist in cracking and maintenance welding for the mining industry.
Making Australia our biggest market and helping us to improve and develop.
Leading the development of interrun peening for weld repairs to achieve repairs that are at least as good as the original weld.
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Robustness of HFMI
A research paper where we treated welds of low quality, showing the potential of HFMI and our equipment. The Weld-Hit equipment produced at least the same quality as the competitors for a tool radius of 1.5 mm. With our 2 mm tool, we also showed a significant improvement.
This paper is the main reference for the reduced weld quality requirements before treatment as introduced in IIW 2nd edition 2025.
Weld-Hit is Machine 1 in the paper Link
