Titanium wire is highly resistant to bending - so you can get away with producing tent pegs that are very thin. They are remarkably strong in good soil but because of their thinness are not very good for loose or soft ground.
Nordisk says: Ultra light, robust and handy titanium tooth peg
The 2g titanium tooth peg is the ideal combination of strength, weight and size. The minimalist design ensures a highly functional peg, that works well in a variety of ground, especially hard-packed soil, rocky and stony areas where a traditional peg will not go. The titanium construction allows you to confidently hammer the nail into place, and the guy rope makes it easy to drag the peg back up.