Advanced Plumbing Tools: PEX Crimpers, Pipe Cutters, Flare Tools, and Press Fittings

PEX Crimping and Expansion Tools

PEX (cross-linked polyethylene) tubing has largely replaced copper for residential water supply lines. It flexes around corners, resists freezing damage, and installs faster than copper. Two connection methods dominate: crimp rings and expansion fittings. The tools for each are different and not interchangeable.

PEX crimp tools compress a copper crimp ring around the tubing over a brass fitting. The crimp ring squeezes the tubing against the fitting barbs, creating a watertight seal. Crimp tools come in sizes matching the tubing (1/2-inch and 3/4-inch are most common residential sizes). A go/no-go gauge checks each crimp to verify it meets code requirements.

PEX expansion tools (for expansion-type fittings like Uponor/Wirsbo) expand the tubing and an expansion ring, then slide the assembly over the fitting. As the PEX contracts back to its original diameter, it squeezes the fitting and creates a joint that actually gets stronger over time. Expansion fittings are the premium PEX system — more expensive but with fewer flow restrictions because the fitting does not protrude into the tubing bore.

For a single bathroom remodel, renting a PEX tool makes more sense than buying. Crimp tools rent for $30 to $50 per day. Expansion tools are more expensive ($50 to $100 per day) but the system is faster for larger projects. If you are replumbing a whole house, owning the tool saves rental costs after the second or third project.

Copper Pipe Cutters

Tubing cutters make clean, square cuts on copper pipe without deforming the tube. A standard tubing cutter scores the pipe as you rotate it and tighten the cutting wheel. The result is a perfectly round, burr-free end ready for soldering. A hacksaw also cuts copper but leaves a rougher edge that needs more preparation.

Mini tubing cutters fit into tight spaces where standard cutters cannot swing — behind walls, under cabinets, and near existing fittings. They have a smaller cutting wheel and a compact body. The tradeoff is slower cutting and limited size range. Keep both a standard and a mini cutter in your plumbing kit.

Deburring tools remove the slight inner burr left by the cutting wheel. This burr restricts water flow and creates turbulence that accelerates corrosion. A few twists of a deburring tool inside the cut end cleans it up in seconds. Never solder a joint on an un-deburred pipe — the burr also prevents proper flux and solder penetration.

For larger copper pipe (1-inch and above), a ratcheting pipe cutter provides the leverage to cut through thicker wall tubing. The ratchet mechanism lets you make incremental cuts in tight spaces where you cannot rotate a standard cutter around the pipe.

Flare Tools

Flare fittings join copper, brass, and soft steel tubing for gas lines, refrigeration, and high-pressure applications. A flaring tool shapes the tube end into a cone that mates with a flare fitting nut. When the nut is tightened, the cone compresses against the fitting body, creating a metal-to-metal seal that does not require solder or adhesive.

A flaring bar holds the tubing at the exact height for a correct flare. The yoke (the part with the cone) screws down to form the flare. Proper technique: cut the tubing square, deburr inside and outside, slide the flare nut on before flaring (you cannot add it after), clamp the tubing in the bar with the correct amount protruding, and screw the yoke down smoothly. An uneven flare leaks.

Double-flare tools create a folded-over flare that is stronger and more resistant to cracking than a single flare. Most automotive brake lines and many gas applications require double flares. The process adds one step — an adapter forms the initial lip before the yoke folds it over into the double flare.

For gas line work, flare connections are common on flexible gas connectors for appliances like stoves, dryers, and water heaters. The work requires a gas-rated thread sealant on threaded connections and a leak test with soapy water or a gas leak detector after every connection. Gas line work may require a permit and inspection in your jurisdiction — check local codes.

Press Fitting Systems

Press fittings join copper, PEX, and stainless steel pipe without solder, glue, or crimping. A battery-powered press tool applies thousands of pounds of force through specially shaped jaws to deform the fitting around the pipe, creating a permanent, code-compliant connection in seconds. It is the fastest joining method for any pipe material.

The press tool and jaws are specific to each fitting brand and pipe material. ProPress (copper), Viega MegaPress (black iron and stainless), and various PEX press systems each have their own jaw profiles. Using the wrong jaw on the wrong fitting creates a joint that appears connected but does not seal properly.

The cost of press tools is the barrier — professional-grade press tools cost $2,000 to $5,000. For a homeowner doing one project, renting is the only practical option. Some plumbing supply houses rent press tools by the day. The fittings themselves cost more than solder fittings but the labor savings on large projects are substantial.

Press fittings have an indicator feature — an unpressed fitting has a visible gap or dot that disappears when the fitting is fully pressed. This makes quality control easy: walk the job and visually verify every fitting before pressurizing the system. A missed fitting under pressure creates a dramatic failure, so the visual indicator is a critical safety feature.

Frequently Asked Questions