PEX expanders stretch the ends of cross-linked polyethylene (PEX) type A tubing and its expansion ring to accept cold-expansion fittings. The tubing and ring shrink back to size to form a seal and hold the fitting in place. Cordless PEX expansion tools provide smoother, more uniform expansion of tubing for a tighter grip on fittings than manual tools. Expansion heads attach to the cone of an expander and into slide into tubing of a matching size to widen it for the fitting.