The head of these hex wrenches pivots, allowing you to get access into numerous tight places and achieve speedier running in for final tightening (with the same hex or via torque wrench). Unlike a standard hex that only gives you 90-degrees, the flex head can be quickly adjusted. You simply move the handle to the angle that works best in the situation then turn (it's like a tight, square drive U joint adapter; there is no screw to lock it). Often you can simply flip the handle for another turn without disengaging from the socket head. The short end or long end can be used as the driver. I start screws with the long end then simply flip the wrench for snugging down.

I bought mine after I saw a bicycle mechanic using one. I've used mine *hard* for bicycle maintenance for over a year with no appreciable wear (they're chrome-plated vanadium steel). While elegant looking, they have never failed to bust loose stuck bolts, especially stainless ones in aluminum or even steel threads. I gave a set to a Mechanical Engineer whose hobby is designing high-end racing recumbents for setting human powered vehicle records. He was also thrilled with them.

-- Fred Larimer

Pivot Head Hex Wrenches
$30
(metric or inches)
Available from Garrett Wade

or $32 from Amazon