What is the highest loft a club can have?

A measurement, in degrees, of the angle at which the face of the club lies relative to a perfectly vertical face. Technically, iron loft and wood loft are measured slightly differently, but the effective result is the same. Loft gives you an idea of how far and how high the ball will go. Drivers are the least-lofted clubs (not counting putters), while wedges are the most-lofted. Driver lofts for most players run between 7.5 and 12.5 degrees. Clubs increase in loft through the set until reaching the lob wedge, which is usually lofted around 60 to 64 degrees.

Source: about.com