Ground Valve Casing Mandrel - 0.674 inches

For use on Czechoslovakian Trumpet and cornetsThese are solid steel mandrels used to remove dents from valve casings and to straighten casings if they are sprung. Easier, faster and more safe to use thanreamers and almost impossible to damage a casing using these mandrels. They are not adjustable, so you must know the size you need or the brand and model of the instrument. Precision measuring is helpful.The recommended procedure for use:_Mount the instrument on a wood assembly mandrel in a vise._Thoroughly clean the casings_Select the proper size mandrel for the instrument and insert it all the way into the casing._When ready to hit the mandrel, STRIKE SHARPLY. It is the quantity of hits that raises the dents and straightens casings, not the force used. Strike firmly-not hard._Use the side of a rawhide mallet and strike the small end of the mandrel with many small and repeated taps. Use sideways and up and down hits. Aim at port intersections.ORDER THE EXACT SIZE. MANDRELS ARE NOT ADJUSTABLE