Or
"Gripper jaws can be a great way of getting round part movement in roughing operations, this is by use of teeth in the jaw which bite into the material.
This biting can also be a great way to get round problems using black bar or other rough material.
The depth of the backstop on the jaw can be adjusted by using screws, these screws are ground and hardened to give you a good backstop for the component.
3087 and 3083 are for gripping bar and do not have the backstop inbuilt into the jaw."
