metal stitching service provider Archives

Metal Stitching And Metal Locking Services

Metal Stitching, also known as Cold Metal Repair or Metal Locking, is a means to restore broken cast iron, cast steel, or aluminum without welding or heat.
Instead of melting the metal like welding does, this method uses specially designed metal keys and stitching pins (locks) to pull the cracked edges together and seal the fracture permanently.

It’s a common fix in heavy industries like,

Marine engine blocks and crankcases
Turbine casings and power plants
Covers for pumps, compressors, and generators
Big machines are used in industry

Why Not Just Weld It?

It sounds straightforward to weld on cast parts, but in reality, it’s not:

Heat makes things bend.
The metal gets weaker because the way its parts work changes.
There may be new cracks around the welded area.
Metal stitching doesn’t have any of that because there is no heat.
The casting’s original strength stays the same.

How the locks and keys really work

The magic of metal stitching lies in installing metal keys and stitching pins directly into the crack.

How to do metal stitching step by step

Step 1: Stop the Crack from Spreading

Small holes are drilled at each end of the crack.
This freezes the crack in place.

Step 2: Install Metal Keys (Locks)

Slots are carefully machined along the crack.
Precision metal keys are inserted into the slots.

What the keys do:

Pull both sides of the crack tightly together
Distribute stress across the repaired area
Restore strength equal to — or even stronger than — the original casting

Step 3: Install Stitching Pins

Small holes are drilled which are perpendicular to the crack.
To seal the crack, metal stitching pins were screwed.

What the pins do:

Hold the area in compression
Make the repair pressure-tight (no leaks — oil, gas, or coolant)

Step 4: Finishing

The repaired surface is machine-smooth and flush.
After finishing, you can barely tell the crack existed.

Why Metal Stitching is a Game Changer

Benefit: What it means

No heat involved, no distortion, no internal metal damage
Strong reinforcement: Strength equal to or greater than the original casting
Leak-proof, Perfect for high-pressure applications
Work done on-site. No dismantling, minimal downtime
Saves money: 60–80% cheaper than replacing the component

Where We Typically Use It

Cracked diesel engine blocks
Turbine or pump casings
Compressor housings
Marine engine frames and bedplates
Generator casings

Metal Stitching And Metal Locking Services uses precision tools, keys, and locks to repair cracks in damaged engine blocks without heat, without distortion, and without messing with the metal’s original strength.

Why R A Power Solutions?

We’re not new to this — we’re experts at this.
With 45+ years of experience and thousands of successful repairs globally, R A Power Solutions repairs:

Engine blocks
Turbine and pump casings
Cylinder liners
Compressor housings

For more information , see the metal stitching and metal surgery process, Metal Stitching And Metal Locking Services, crack casting repair, turbine casing crack repair on site, and crack repair and damaged casting rectification. We also provide crankshaft grinding repair services, crankshaft grinding machines, rebabbitting bearings, etc. Contact us at rajshahani@rapowersolutions.com, info@rapowersolutions.com, or call us at +91 9582647131 or +91 9810012383.

Metal Stitching And Metal Locking Services Metal Stitching, also known as Cold Metal Repair or Metal Locking, is a means to restore broken cast iron, cast steel, or aluminum without welding or heat.Instead of melting the metal like welding does, this method uses specially designed metal keys and stitching pins (locks) to pull the cracked … Continue reading “Metal Stitching & Metal Locking Services for Marine and Power Plants “

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.

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 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

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

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”