Designed specifically to fit the 16-oz. Bonny Doon urethane hammer (and the larger-sized original 10-oz. model), this insert is threaded to be interchangeable with the flat-face insert in the hammer, giving you a domed, 95-durometer face ideal for forming curves.
• If you own one of the larger original 10-oz. Bonny Doon urethane forming hammer (110903), choose this larger-sized replacement insert to properly fit your hammer.