Marshalltown M/T83 Brick Jointer 3/8in & 1/2in The Marshalltown M/T83 Brick Jointer is made from a high carbon steel which is hard tempered and polished. It is designed to give a professional finish to joints between bricks. M/T83 Features: Designed to give a professional finish to joints between bricks. Made from high carbon steel, hard tempered and polished. Convenient double ended cranked design. M/T83 Specification: Size: 10 and 12mm (3/8 X 1/2 in).