The line of 1/4 inch sockets is used primarily for delicate work such as electronics, pneumatics, and alectromechanics. The application ranges are as follows: Socket opening size: 5/32 inch to 9/16 inch and 4/15 mm. Torque applications for sockets, handles, and accessories: 35-500 in-lbs. The 3/8 inch socket line, is used primarily for automotive maintenance and general mechanical work. They can withstand higher torques and more work space is needed to use them, but they have broader application ranges. Socket hex sizes: 1/4 inch to 1 inch and 6-26 mm. Torque applications for sockets, handles, and accessories: 270-2200 in-lbs. The 1/2 inch socket line, like the 3/8 inch line, is used primarily for automotive maintenance and general mechanical work. They can withstand higher torques and more work space is needed to use them, but they have broader application ranges. Socket hex sizes: 1/4 inch to 1-7/16 inch and 8-36 mm. Torque applications for sockets, handles, and accessories: 1,100-5,000 in-lbs.