The key factor in choosing a vise for a knee mill is the vise opening, and whether or not a swivel base is needed. Workholding selection for HMCs and VMCs should be based on desired density, clamping station opening size, clamping pressure needed and shape of the part.
High density requires double station vises. These vises have two clamping stations, pushing the workpieces toward the stationary vise jaw block between them. They can be equipped with special carvable jaw plates or carvable jaw blocks.
The next highest workholding density can be achieved with cluster vises where multiple vises are machined into a single body. The advantage of cluster vises is that they remain in exactly the same relationship to each other compared to trying to align multiple vises in a workholding setup.
Highest workholding density is achieved when the movable vise component is a module that can be moved in small increments on a serrated base. The modularity of these systems allows the user to configure the equivalent of custom fixturing with standard off-the shelf components.
Additional workholding options include:
Self-centering vises are very similar to double-station vises except that they are designed to precisely locate components to their respective centers. They are accurate to within 0.0002 inch repeatability.
Zero-point workholding systems are designed to integrate with new or existing workholding devices. They provide multiple workholding stations with ultra accurate setup on either HMCs or VMCs, thereby completely eliminating operator setup errors.
Five-axis clamping systems are designed to take advantage of the five-axis machining capabilities of the latest machining centers.
Hydraulic actuated vises and high density towers are available for production line clamping applications. Jaw selection is important when choosing a workholding setup. Jaw plates affect part contact and setup repeatability. Many jaw options are available for specific applications.
There are many vise and workholding accessories that make the clamping job easier and more productive—such as speed handles, special vise handles, and a complete array of different workstops, specialty jaw plates and parallel sets.                                     

 About our company
First-rate Mold Solution Co., Ltd. in China, provide industry design,mold design,mold manufacturing,molding analysis,project management service.
  About our website
our website has a lot of professional knowledges in mold industry in blog and news, also we are interested in CAD/CAM/CAE, AUTOCAD,NX,Moldflow,we welcome professional engineer,mold maker and someone who are interested in injection molding,plastic product,injection mold and mold industry to our section of blog and news,we would like to share with them