A new range of tools has been developed for punching dimple-free holes in miniature tubing. A "clean" hole is punched by inserting the tube over a mandrel. The material is then fractured as a precisely guided punch enters into a closely controlled clearance in the die cavity in the mandrel. Standard tube piercing and notching tools up to 5" diameter may be powered to pierce through one or both sides of a tube. Applications for the mini-mandrel include medical and dental instruments, aircraft parts, auto parts and small heat exchangers.