Grizzly 3400-3501 Clamping Kit for 1/2-Inch T-slots, 58-Piece Our Clamping Kits are among the best in the world. All the blocks bolts nuts and hold-downs are case hardened Each clamping kit includes: studs step block pairs T-nuts flange nuts coupling nuts and end hold-downs The Model G1075 set fits 1/2-Inch T-slots and includes 3/8-Inch studs