1/4 IN The JPW Industries Inc WC21307 56, Forged Super-Junior C-Clamp is a precision-made clamp that is ideal for use with a variety of materials. This clamp is made from forged steel and is designed to provide maximum strength and durability. The WC21307 56, Forged Super-Junior C-Clamp is also easy to use and is perfect for use in a variety of applications.