Park tool threadless saw guide sg8specially designed to accommodate wider carbon specific saw blades the sg 8 threadless saw guide ensures a straight clean cut on 125 4mm 1 1828 6mm and 1 1431 8mm threadless fork steerer tubes it also works great when cutting handlebars or other round tubes from 22mm to 33mm simply clamp the sg 8 onto the tube and cut letting the sg 8 guide the hacksaw blade the sg 8s non scratching composite body incorporates steel threads and a steel rein