The popular Pitbull fixture clamp is now available in a machinable version.  The clamp has positive down force and a very low gripping profile, making it well suited for machining pieces complete in one set up.The Machinable Pitbull clamp is made of tool steel and heat treated to about 43RC for long life, yet still machinable.  There is additional material on the clamping face to allow for machining a radius.  It is  available in two sizes with 6,000 lbs. and 12,000 lbs. of holding force.