U.S. fastener imports increased 29.9 percent in value to $2.09 billion with a growth of 23.7 percent to 1.43 billion pounds in volume during the first six months of 2011, the Industrial Fasteners Institute reported.U.S. fastener exports also posted strong gains during the first half of 2011, rising 16.9% in value to $1.44 billion. But fastener exports declined 30.4% by weight to 793,315,558 pounds. […]