Mechanical Engineering - Machine Design - Discussion
Discussion Forum : Machine Design - Section 2 (Q.No. 21)
                   
                                       
                                21.
Screws jacks have multiple threads.
 
                                    Discussion:
4 comments Page 1 of 1.
                
                        VIKRANT said: 
                         
                        1 decade ago
                
                This is due to the following reasons:
1. Mechanical advantage of multi-start screw is less than single start screw. Thus effort required to raise a particular load is more in multiple start screw.
2. It is likely that the self-locking property may be lost in a multi-threaded screws.
                1. Mechanical advantage of multi-start screw is less than single start screw. Thus effort required to raise a particular load is more in multiple start screw.
2. It is likely that the self-locking property may be lost in a multi-threaded screws.
                        VRC said: 
                         
                        9 years ago
                
                A jackscrew's threads must support heavy loads. In the most heavy-duty applications, such as screw jacks, a square thread or buttress thread is used, because it has the lowest friction. In other application such as actuators, an Acme thread is used, although it has higher.
                
                        Priyanka said: 
                         
                        10 years ago
                
                A jackscrew's threads must support heavy loads, the most heavy-duty applications, such as screw jacks, a square thread or buttress thread is used because it has the lowest friction.
                
                     (1)
                
            
                        Paras said: 
                         
                        9 years ago
                
                Screw jacks are used for heavy load application.
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