Home / Retail Showroom / 1/2in-20 Plain Flanged Nut 12N 1/2in-20 Plain Flanged Nut 12N 1/2″-20 plain flanged nut. This nut is used on many standard 1/2 u-bolts. • 1/2″-20 Category: Retail Showroom Product ID: 3128 Related products CASTLE® FIREBALL PLUS™ Buy now 2 5/8in Shackle Strap 115052 Buy now 3.5K Slipper Spring 1203T3 Buy now CASTLE® FIREBALL™ Buy now