Metal Stitching

Metal stitching is a trusted and class-approved cold repair method for cracked or damaged cast iron parts. At YAF Engineering, we utilize the industry-leading Lock-N-Stitch® metal stitching system, known for its mechanical strength, sealing reliability, and suitability for marine and industrial applications.

Our certified technicians ensure that each repair is carried out with precision, in compliance with classification society standards, and under strict quality control procedures.

Advantages of Metal Stitching with Lock-N-Stitch®:

Cold repair process — no heat input, eliminating risks of thermal distortion or residual stresses
Gas-tight and liquid-tight sealing capability
Restores structural integrity equal to or greater than the original cast part
Fast repair turnaround — ideal for in-situ or emergency situations
Permanent solution for high-value components
Approved by major classification societies (ABS, DNV, BV, etc.)

Typical Components Repaired:

Diesel engine blocks (main bearing saddles, liner bores, outer casing)
Steam, gas, and hydro turbine casings
Pump and compressor casings
Cracked gearboxes and flywheel housings
Damaged bolt threads and broken stud areas using full-torque insert technology

How It Works

The Lock-N-Stitch® system involves drilling precision holes across the cracked area and inserting interlocking metal pins and locks with proprietary thread geometry. This distributes mechanical load evenly while pulling the crack closed without introducing thermal stress. For areas where studs or threads have failed, full-torque inserts restore thread strength beyond the original.

This process creates a durable, pressure-resistant, and fatigue-resistant bond, making it ideal for engine blocks, cylinder heads, bearing housings, and more — all without welding.