A collet for a fastener installation tool having a pull section with a fastener engagement end and a plurality of teeth. The teeth include a first tooth with a first inner diameter, and each of the remainder of teeth includes a second inner diameter, the first inner diameter being greater than the second inner diameter. The pull section includes a protrusion extending from the fastener engagement end, thereby extending the length of the pull section. The pull section includes a cross-sectional thickness, wherein the collet is adapted to engage a pin member having a locking portion with a first diameter and a pull portion with a smaller second diameter. An increase in the difference between the first diameter of the locking portion and the second diameter of the pull portion of the pin member allows for a corresponding increase in the cross-sectional thickness of the collet, thereby extending the fatigue life of the tool.