Vises are an essential tool in precise milling. Apart from selecting the right size vise for your machine, choosing the proper vises to hold workpieces is essential to making sure your workpiece is secure when it is milled. There are a three types of vises you'll typically encounter in CNC milling - the machinist vise, the CNC vise, and the toolmaker vise.
Machinist Vise
It is popular due to its ability to be used in a variety of ways, the machinist's vis is an excellent multi-purpose tool. It has an flanged base that offers greater stability and facilitates an easier clamping of the mc power vice. It's great however it occupies the space of. The majority of machinist vises that are top quality have "lock-down" vises, which means that the moveable jaw is less likely to move upwards when the vise screw is tightened
CNC Vise
The CNC vise is a smaller version of the machinist's vise however, it still has the strength and rigidity of an industrial vise. Its smaller stance means you can use multiple vises simultaneously , but with a limited amount of space. CNC vises are precision ground on several sides, so they can be used sideways and horizontal. It's a bit difficult to secure them to the table without the flange but this can be solved by using table clamps specially designed with the self-centering vise. CNC Vises are also a lock-down style.
Toolmaker Vise
The toolmaker vises are small cost, less expensive, and surprisingly precise, but they are more difficult to operate, as the method for tightening utilizes using a multistep latch rather than the full length screw. Vises for toolmakers are most preferred when work has to be transferred from one machine to the next. The work can be put in the vise for the toolmaker and you can move it to an additional machine, like to an a mill or drill press. The lock-down design prevents the jaws from lifting. However, vises made for toolmaking do not typically come with accessories like interchangeable jaws or work stops.
Workholding History
Today's staples of workholding are the result of trial and error and creativity. While the idea of locking workpieces has existed for centuries, early examples were found in Egyptian tombs. The Egyptians utilized an robe to wrap around the workpieces, then inserting a stick. It was used to hold the piece.
Quick change systems was invented and the modern vise was created in the middle of the 1800s. Early wooden screw vises were upgraded with precise ground metal designs. Then came the idea of locking down vises to, once again enhance their precision. Before lockdown vises, the jaws surrounding the workpiece would lift and tilt slightly as the screw moved forward, as it didn't apply force directly to the jaw that could move. The lockdown vises incorporate a joint mechanism underneath and inside the jaw which converts the force of forward from the screw into forward or downward forces to its jaw. This ensures that the jaw remains straight and down even when the work is raised . It only keeps the tops of the jaws.
Workholding is constantly being reevaluated by the makers and the people who do the work in the field of machine-making, so this is by no means the final word on vises. However, it's a fascinating overview of how the vise on your bench came about.