Shoulder screws have a long, unthreaded, cylindrical shoulder that allows for the rotation of attached parts like pulleys, gears, moving parts of engines and mechanical assemblies, and rolling wheels
            
        
            
                        Tech Data (PDF)
                
                                        
            
    | Type | Shoulder Screw | 
| Style | Socket Head | 
| Size | 1/4"-20 | 
| Length | 3/4" | 
| Material | Carbon Steel | 
| Thread Type | USS. UNC | 
| Shoulder Size | 5/16" | 
| Shoulder Length | 3/4" | 
| Thread Style | Partailly Threaded | 
| Specifications | ASTM A574, ASME/ANSI B18.3-2002 |