N80A Ball Type Dent Balls
Set of 3 balls (10-24 thread) that can be used on the N54 Knuckle Tools, the N68 Right Angle Mandrel and the N91B Tapered Mandrel. These dent balls are designed spherically, so there is no possibility of making lateral ridges in the tubing. Made of chrome steel with a satin sandblast finish. This finish has minute pores which hold Vaseline (or any other lubricant) longer for easy use in tubing.
Better Dent Work Using Your Dent Hammer…
Normally, you would use round balls (N80D’s or E’s) screwed on 5/8” or 3/4” rods like N31’s or a N74 mounted in a vise with a V-Block to form the tubing around. With this setup you would use a F10A or B dent hammer to burnish and push the metal back to a nice cylindrical form. You are not supposed to hammer, directly ON a ball. You use the ball as a form or mandrel and then hammer right next to the ball radius; essentially making the ball a hammer or form, from the inside out.
Remember, the more you hammer direct, the thinner and harder and larger the metal gets and work hardening sometimes creates cracks. You may have to anneal, and that gets messy with all the posts and sometimes tone holes. But, if you label everything and draw some pictures you will probably be okay, anyway, lacking a Z60 and either a Z61, Z61E Base or a Z61S Stand and some toys, of course. Then, the dents just kind of roll out. There are times however, that you must anneal BEFORE using even the dent machine.
A NOTE ON BALLS IN HALF SIZE GRADUATIONS
These balls help provide a more precise fit, because many new instruments are thinner than they used to be, these in between sized balls allow removal of dents without over expanding the tubing. They produce a better finish especially in the new French Horns, trombones and trumpets.