Renfroe Model AST-S is the same as the Model AST with the exception that it incorporates a “LockClosed” feature which facilitates attaching to the beam.
Renfroe Model AST-S Locking Style Clamp
Developed primarily for lifting, turning and stacking lightweight beams and structural shapes. The horizontal shackle permits a beam to be lifted with the web in a near horizontal position by placing the clamp on the load with the shackle positioned over the web, and between the flanges. With a beam lying in a horizontal position, and the clamp placed with the shackle over-hanging the flange, the beam can be lifted, turned 90 degrees, and raised in a vertical position.

| Rated Capacity ( Tons ) | Plate Thickness A ( in. ) | MAX. B ( in. ) | C ( in. ) | D ( in. ) | E ( in. ) | F ( in. ) | G ( in. ) | H ( in. ) | J ( in. ) | K ( in. ) | Weight ( lbs. ) |
| 1/2 | 0-3⁄4 | 10 3⁄4 | 6 11⁄16 | – | 1 3⁄4 | 6 3⁄16 | 1 5⁄8 | 2 1⁄2 | 1⁄2 | 1 1⁄2 | 10 |
| 1 1⁄2 | 0-3⁄4 | 13 | 8 1⁄2 | – | 2 1⁄2 | 7 | 2 9⁄16 | 3 | 5⁄8 | 1 1⁄2 | 20 |
| 3 | 0-1 1⁄2 | 19 1⁄4 | 12 1⁄2 | – | 3 3⁄4 | 11 | 3 | 4 5⁄8 | 3⁄4 | 1 1⁄2 | 50 |