Made of flexible spring steel, cold rolled, hardened, and tempered. Chamfered ends simplify insertion. Handy kit for shop toolroom or toolbox. On hand when needed saves time and money. The plastic compartment box is easy to store. The Precision Brand®, 300 Piece Roll Pin Asst, contains 10 each of 1/16″ and 5/64″ diameters by 1/4″, 3/8″, 1/2″, and 3/4″; 10 each of 3/32″ diameter by 5/8″, 1″, 1-1/4″, and 1-1/2″; 8 each of 1/8″ diameter by 5/8″, 1″, 1-1/4″, and 1-1/2″; 7 each of 5/32″ and 3/16″ diameters by 1″, 1-1/4″, 1-1/2″, and 1-3/4″; 8 each of 7/32″ diameter by 1-1/4″, 1-1/2″, 1-3/4″, and 2″; 7 each of 1/4″ diameter by 1-1/4″, 1-1/2″, 1-3/4″, and 2″; 5 each of 5/16″ diameter by 1-1/4″, 1-3/4″, 2″, and 2-1/2″; 3 each of 3/8″ diameter by 1-1/2″, 1-3/4″, 2″, and 2-1/2″.