Check the listing for details. MHC 1/2 Inch Round Collet R8 231-4732. Condition: New. Listed at 12.99 USD. This MHC 1/2 Inch Round Collet R8 231-4732 is a must-have for anyone in the business and industrial industry. Made in China, this collet is the perfect addition to your workholding and toolholding collection. The size of the collet is 3/8 inches, making it ideal for a variety of applications.