Thomas Machine & Foundry > Fraser Marine Products > Chock Open Large Chock Open Large Chock Open Large Large open chock cast in marine grade aluminum. Weld-down design provides secure installation. Heat treatment available for applications requiring maximum strength. View Large Open Chock Drawing Request A Quote Back to All Products Get in TouchWhether you need casting, precision machining, or finishing services, Thomas Machine & Foundry is here to help. Request A Quote