Metal Stitching | Metal Locking | Repair of Cast Iron by Metal Stitching – RA Power Solutions

When cast-iron or aluminum engine blocks crack, the traditional fix—welding—is often expensive, risky, and destructive. At RA Power Solutions, we specialize in advanced cold repair techniques—metal stitching and metal locking—that restore structural strength without applying heat, requiring machining, or dismantling equipment.

With the improvement in repair technology now, it is possible to repair the crack in cast iron, steel, or aluminium component by metal stitching and metal locking process. The main feature of repair of crack or damaged casting by metal stitching, metal locking, and metal surgery is that process does not require disassembly of the equipment and taking the crack or damaged part to the workshop.

What Are Metal Stitching & Locking?

  • Metal Stitching is a precise, cold repair method. Technicians drill a series of aligned holes across the crack, insert metal “keys” or studs into a dovetailed pattern, and tighten them so they interlock—effectively sealing the fracture and restoring rigidity.
  • Metal Locking reinforces the stitching with custom-shaped metal inserts that prevent the crack from spreading further and enhance the repair’s long-term durability
Damage Area of Engine Block
Damage Area of Engine Block
New Casting Inserted for Repair of Engine Block
New Casting Inserted for Repair of Engine Block

RA Power Solutions has the team of experience technicians. They can travel to the site with tools and consumables required for metal stitching and metal locking undertake the repair.We repair cracks by metal locking and metal stitching while maintaining the original profile. In most cases, the process does not require any machining. Scientific tests prove that the repaired crack portion has greater tensile strength than before.

RA Power Solutions with the experience of forty five years in this field extends metal locking and metal stitching services for repair of damaged casting. We can also execute the repair while the vessel is sailing. We offer the lowest cost compared to our competitors.

Metal Stitching | Repair Cast Iron | Cast Iron Repair

Get your crack or broken components manufactured out of cast iron, cast steel or aluminium repair by metal stitching and metal locking process. RA Power Solutions with experience of more than four decades have successfully repaired thousands of major engine components and components installed in heavy industries all over the world.

The damage to the component may be serious, or the cracks are multiple. RA Power Solutions engineers have the experience, know how and necessary tooling to execute the most complicated and serious damage which takes place due to accidents in cast iron, cast steel and aluminium casting.

For more information on cold metal stitching engine block, cast iron engine block repair, metal stitching surgery, metal stitching engine block, repair cast iron, and metal stitching of engine block please email us at rajshahani@rapowersolutions.com or info@rapowersolutions.com, or call us at +91 9582647131 or +91 9810012383.

Metal Stitching & Metal Locking of Engine Block Under Process
Metal Stitching & Metal Locking of Engine Block Under Process
Metal Stitching of Engine Block by Special Keys & Locks
Metal Stitching of Engine Block by Special Keys & Locks

FAQs:

1. What are metal stitching and metal locking?

Metal stitching involves drilling a series of aligned holes across a crack, inserting interlocking metal keys or studs, and tightening them to seal the fracture. Metal locking uses custom-shaped inserts that reinforce and prevent crack propagation.

2. Do these methods require dismantling the equipment?

No. We perform the repairs in situ, without disassembling the machinery or removing the damaged part from its position

3. Will the original surface or shape be affected by the repair?

We maintain the original profile after metal stitching and locking, and in most cases, no machining is needed afterward

4. Is the repaired area as strong as the original component?

Yes. Scientific studies show that crack areas repaired by metal stitching and locking often have greater tensile strength than before

5. Can repairs be performed while the vessel is underway?

Absolutely. We can execute repairs while the vessel is sailing, minimizing downtime and logistical challenges

When cast-iron or aluminum engine blocks crack, the traditional fix—welding—is often expensive, risky, and destructive. At RA Power Solutions, we specialize in advanced cold repair techniques—metal stitching and metal locking—that restore structural strength without applying heat, requiring machining, or dismantling equipment. With the improvement in repair technology now, it is possible to repair the crack … Continue reading “Metal Stitching | Metal Locking | Repair of Cast Iron by Metal Stitching – RA Power Solutions”

Metal Stitching and Thread Repair Inserts – RA Power Solutions

One of our clients informed RA Power Solutions about damage to the cam case cover of a MAN diesel engine on board a vessel sailing near China. After reviewing the details and photographs, we observed that the cam case cover had broken into pieces. We also found that the threads on the engine body and the dowel pin were damaged.

Cracked Housing of Engine Block
Cracked Housing of Engine Block
Broken Area
Broken Area
Damaged Upper Threads
Damaged Upper Threads

RA Power Solutions Executes Onboard Repair of Engine Block and Cam Case Cover Sitting Area:

RA Power Solutions deputed their team of technicians on board the vessel, and they executed the repair of engine block, cam case cover sitting area by the following procedure:

  • The broken bolt which remained inside the thread hole was drilled out.
  • The damaged threads on cam cover sitting area on entablature was removed by drilling new blind holes, suiting the new M12 Helicoil thread inserts.
  • Re-tap holes for the new M12 Helicoil thread inserts was done carefully.
  • New M12 Helicoil thread inserts were installed in the engine frame/ entablature.
  • The 2 guide pins for the roller guide housing were removed, taking due precaution.
  • Technicians installed a new roller guide housing using correct M12 hexagon bolts. They also included the newly introduced 10 mm washers.
  • Technicians completed the final alignment of the roller guide housing. They then tightened the bolts using the correct tightening torque.
  • Technicians drilled two ø8 mm guide pinholes in both the roller guide housing and the engine frame. Afterwards, they installed new guide pins.
repair of Threads on Engine Block Under Process
repair of Threads on Engine Block Under Process
Repair of Thread Hole by Metal Stitching
Repair of Thread Hole by Metal Stitching

What Is Metal Stitching?

Metal stitching, also known as metal locking, uses a cold repair technique to fix cracked or broken cast components. This method eliminates the need for welding. The process restores original strength and ensures pressure-tight sealing through mechanical locking of stitching pins and studs.

Advantages of Metal Stitching Over Welding:

  • No heat means no distortion, warping, or residual stress
  • Maintains alignment and surface profile of the original cast
  • Suitable for cast iron, steel, aluminum, and other alloys
  • Creates permanent, pressure- and liquid-tight repairs
  • Enables on-site repairs with minimal disassembly
  • Often stronger than the original material
Damaged Thread Hole Under Metal Stitching and Metal Locking
Damaged Thread Hole Under Metal Stitching and Metal Locking
Metal Stitching of Bottom Area of Threaded Hole to Give Extra Strength
Metal Stitching of Bottom Area of Threaded Hole to Give Extra Strength

Our Process at RA Power Solutions:

  • Damage Inspection & Assessment: Document cracks and thread damage
  • Thread Repair via Stitching & Inserts: Use stitching keys and Helicoil/insert methods
  • Post-Repair Finishing: Grind and align to restore original surface
  • Testing & Validation: Conduct pressure or stress tests to ensure integrity.

With decades of experience and advanced cold-repair tools, RA Power Solutions delivers efficient and durable repairs without removing heavy castings.

Cam Cover Sitting Area of Engine Block After Repair
Cam Cover Sitting Area of Engine Block After Repair

For more on metal stitching and metal locking, metal stitching of engine block contact us today email us at rajshahani@rapowersolutions.com, info@rapowersolutions.com, or call us at +91 9582647131 or +91 9810012383.

FAQs:

1. What is metal stitching, and how does it work?

Metal stitching, also known as cold metal locking, is a mechanical repair process used to fix cracks in cast iron or cast steel components. It involves inserting stitching pins and locks to restore structural integrity—without welding or heat.

2. When should I use thread repair inserts like Helicoil?

You should use thread repair inserts when original threads in an engine block, casing, or housing become stripped, worn out, or damaged. Helicoils restore the thread’s strength and allow secure fastening, even under high torque.

3. Is metal stitching better than welding for cast iron repair?

Yes. For cast iron and other brittle materials, metal stitching is safer and more reliable than welding. It avoids heat distortion, cracking, and structural weakening, which are common risks with welded repairs.

4. Can RA Power Solutions perform these repairs on-site?

Absolutely. RA Power Solutions specializes in on-site metal stitching and thread repair, including work on marine vessels, power plants, offshore rigs, and remote industrial sites—without the need to remove the equipment.

5. What components can be repaired using metal stitching and thread inserts?

These techniques can repair engine blocks, cylinder heads, gearboxes, cam case covers, pump casings, compressors, and more. These methods can typically restore any cracked or damaged cast iron or steel component.

One of our clients informed RA Power Solutions about damage to the cam case cover of a MAN diesel engine on board a vessel sailing near China. After reviewing the details and photographs, we observed that the cam case cover had broken into pieces. We also found that the threads on the engine body and … Continue reading “Metal Stitching and Thread Repair Inserts – RA Power Solutions”