For many years, the “Holy Grail” for aerospace fastener manufacturers has been the idea of replacing heavier alloy steel and corrosion-resistant nuts and bolts with lower density titanium-alloy fasteners that could provide the same level of mechanical performance and corrosion resistance with a significant weight savings. This dream has remained largely unfulfilled, in part, because of practical limitations with the available titanium alloys. That is, strength-to-ductility issues, limited depth of hardening and increased notch sensitivity have prevented titanium-alloy fastener usage from expanding into new areas. With the development of SPS M761 titanium alloy, some of these substitutions are now possible. Continued development efforts within SPS Technologies are directed at realizing many more substitutions.

This presentation will review standard aerospace fastener materials and the niches they occupy with respect to one another, current titanium-alloy fastener performance capabilities and the obstacles that need to be overcome to raise that performance capability. The development of SPS M761 titanium alloy will be reviewed, and minimum guaranteed property levels currently available will be presented. The goals and progress of the ongoing development work will be discussed.