Metal lock/metal stitching process of crack repair for engine block Metal locking can be performed on site, avoiding the high cost associated with disassembling the equipment and transporting it to the designated workshop for repair. Metal stitching can be done in the limited space available. For metal lock stitching and engine block crack repair, you can contact us at info@rapowersolutions.com or by phone at 0124-425-1615 or +91-9810012383.