CHA devices for pinching off tubing produce a hermetically perfect cold-weld of tube walls; ends are neat and clean. The most common application is pinching off vacuum exhaust tubing of fully annealed OFHC copper. Other soft metals, such as fully annealed aluminium. 070" OD x 010 wall Kovar annealed nickel, thin wall 52 alloy and platinum, can be pinched off. While not primarily for pressure applications, the CHA vacuum seal will hold relatively low pressures (75-100 lbs.).

Jaws are hardened, ground, high speed tool steel (Rockwell C 60 to 65). Extra jaws are available for
replacement if required by heavy usage.