LOCK-N-STITCH Inc.'s proprietary, patented mechanical crack repair process "metal stitching" allows us to permanently repair a crack or blow-out hole without welding. The cracked metal is replaced with special metal stitching pins that we install by drilling and tapping to draw the sides of the crack together. This results in a continuous row of interlocking stitching pins to create a strong, pressure-tight repair. To restore the casting to its original strength, we install locks across the joint line of the pins by drilling a precision hole pattern with special drill fixtures. After the hole pattern is created, the locks are driven in, pulling the repair together even tighter.
The repaired, metal-stitched area is gas-and- liquid tight to create a pressure-tight repair. In addition, metal stitching Dampens and Absorbs Compression Stresses. It also spreads tensile strains and distributes the load away from the original failure point, while maintaining the alignment of the original surfaces.
This metal stitching method is employed mostly on cast iron components, but it is also effective on any other machinable metal, such as ductile iron, steel, aluminum and bronze castings.
If failed weld attempts damaged the metal, a repair may be possible after the affected area has been cut out so that a new piece can be "stitched" in. We can repair components with wall thicknesses from 3/16" to 12" and have the portable machining equipment required to handle difficult machining projects.