As a materials engineer I am commenting on some of the comments here of titanium vs. stainless steel. In a simple pull test titanium per unit of weight is stronger than steel but steel is more durable against scratches, etc. In something that is going to get handled a lot I would prefer stainless way over titanium. A tool like this which needs durability at the contact points I would choose steel over titanium. It is for this reason that knife blades are not made out of titanium.
Spokes30True. Many titanium alloys are very brittle and not well suited to applications where it will be stressed at very small points, such as using it for a wrench of this size. It also can not be hardened to the same degree as steel. It is a great material for structural parts in an aircraft or spacecraft. Not so good as a wrench. Titanium nitride coatings on things like drill bits or screwdriver bits or cutting blades are very effective, but that is microns thick with a suitable base metal.