<div class="htmlview paragraph">This report describes a nonconventional tooling procedure for machining thin-wall titanium pressure tank components. Machining had to be performed with a minimum restraint to avoid any stress buildup which could have an adverse effect on subsequent welding operations. In addition, precise contour and wall thickness tolerances had to be maintained. The tooling method described consists of backing up the workpiece with hydrostone material to withstand the dynamic forces acting between cutting tool and part.</div>