What Is Metal Stitching and Metal Locking? A Trusted Cold Repair Technique: RA Power Solutions

When a metal component cracks—especially in large equipment like engine blocks, compressors, or turbines—repair options can be costly, time-consuming, and risky if not done correctly. One highly effective method that avoids heat, preserves alignment, and restores structural integrity is metal stitching, also known as metal locking.

Understanding Metal Stitching

Metal stitching is a cold mechanical repair process used to fix cracks or breaks in cast metals such as cast iron, aluminum, steel, and bronze. Unlike welding, which uses high heat, metal stitching relies on precision-drilled holes, specially designed stitching pins a nd locks to seal and reinforce the damaged area.
This technique is ideal for industrial applications where heat could distort components or where disassembly isn’t feasible.

Metal stitching under process
Damaged Crankshaft before metal stitching

How the Process Works

Here’s a simplified breakdown of how metal stitching is done:

  • Crack Detection: Identify and inspect the full extent of the crack.
  • Drilling Pattern: A series of holes is drilled along and across the crack.
  • Slot Cutting: A slot is formed to fit stitching locks or keys.
  • Installing Locks: Metal locks are inserted into the slots to mechanically bind both sides of the crack.
  • Threaded Studs: In some cases, overlapping threaded studs are used to seal the crack.
  • Sealing & Finishing: The surface is peened and machined smooth to match the surrounding area.
Metal Loking of Engine Block
Onsite Metal Locking under process

Why RA PowerSolutions?

At RA PowerSolutions, we specialize in on site metal stitching and metal locking for all types of cast components. There is no need for dismantling or transporting the part.
With decades of experience and hundreds of successful global repairs. We help industries reduce downtime, avoid expensive replacements, and restore strength and performance efficiently.

Our services include:

  • Metal stitching of engine blocks, compressors, pumps, etc.
  • On site machining and grinding
  • Repair of crack-prone components like turbine casings and gearbox housings
  • ISO-certified technicians and portable tools
Metal Stitching of Engine Block

If you’re facing a critical breakdown or seeking long-term solutions for metal cracks, RA PowerSolutions is ready to assist with expert, onsite support. Contact us today to learn more or schedule an inspection.

For more details on the Metal Stitching and Metal Locking , Crack Repair by Metal Stitchng email us at info@rapowersolutions.com. Call at +91-9582647131,+91 9810012383.

FAQs:

1. What is metal locking?

Metal locking crack repair process – Metal-lock or metal stitching is a method of repairing fractures to castings, onsite without the use of heat. It involves sinking Metal-lock keys, perpendicular to a fracture. The fracture is then sealed and held rigid by Metal-lace studs

2. How is metal stitching better than welding?

Metal stitching does not use heat, so there’s no distortion or weakening of the material. It preserves the original shape and alignment of the part and is ideal for cast iron, which is prone to cracking when welded.

3. Can metal stitching be done on-site?

Yes, RA Power Solutions specializes in on site metal stitching, allowing us to repair damaged equipment without dismantling or transporting it—saving time, cost, and downtime.

Tri metal Bearing | Crank pin Bearing | Engine Tri Metal Bearing

We are the leading manufacturer and supplier of Tri metal bearing, Engine tri metal bearing, crank pin bearing, main journal bearing and Bi metal Bearing, and Engine bearing for all types of Rotating equipment.

The Bi metal Bearings up to 1500 mm diameter are manufactured by centrifugal process and Tri metal bearings are sourced from our Principles based in UK, Germany, and Japan.

Our specialization in Tri Metal Bearing for crank pin/ main journal of marine engine

RA Power is engaged in extending on site crankshaft repair services all over the world for the last more than 41 years.

It is obvious that whenever the grinding of the crank pin & main journal of the diesel engine or compressor crankshaft is undertaken there is a requirement for under size crank pin and main journal bearing.

It is generally observed that in most cases it is difficult to source under-size bearings from the manufacturer of the engine and compressors as they are not available in the stock. The problem arises when there is a requirement for a special size undersize of the bearing.

We have also observed that in the case of an engine make & model which is more than 15 years old it is rather impossible to source the bearing from the manufacturer of the engine as that particular model is discontinued by the manufacturer.

The ship owners or the customers having old models of engines face this problem of nonavailability of crank pin and main journal bearing.

RA Power Solutions plays an important role in arranging the special & under-size bearing according to the dimensions of the crank pin and main journal obtained after grinding. 

Development & manufacturing of Tri metal & Bi metal Bearing for crankpin and main journal of the crankshaft  

We specialize in the development and manufacturing of under-size-bearing of old and absolute models of engine production which is discontinued by the engine manufacturer.

We manufacture the bearings as per the drawing & technical data available with us or alternatively Tri metal bearings are manufactured by us as per the sample provided by the client.

Our acceptance of a small quantity of undersize and special size bearing of crank pin and the main journal is of great assistance to our client.

We manufacture & supply bearings for all makes & models of marine engines & auxiliary engines which include the following:

Yanmar Engine crankpin & main journal bearing
CKD Skoda Bearing

Daihatsu crankpin & main journal bearing
MAN B&W engine crankpin & main journal bearing undersize

This blog is written by Mr. Raj Shahani (Managing Director of RA Power Solutions India Pvt. Ltd.).

Mr. Shahani is a highly experienced business leader with experience of more than 40 years in the field of Power, Heavy, and Shipping industry. He is Technical Adviser to many shipping and heavy industries across the globe.

For more information on bearing manufacturing company, white metal bearing alloy ingot, or Engine bearing contact us at rajshahani@rapowersolutions.com or info@rapowersolutions.com or call us at +91 9582647131 or +91 9810012383.