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

Basic plumbing repairs need a wrench, a plunger, and some plumber's tape. But anything beyond fixing a drip - running new water lines, rerouting drain pipes, connecting gas appliances, or replumbing a bathroom - requires specialized tools. PEX crimpers, copper cutters, flare tools, and press fittings each solve a specific pipe-joining problem. This guide covers the tools that turn plumbing projects from professional-only into confident DIY territory, along with when to rent versus buy and which connection methods suit different applications.

PEX Crimping and Expansion Tools

PEX (cross-linked polyethylene) tubing has largely replaced copper for residential water supply lines. It flexes around corners without fittings, resists freeze damage because it can expand slightly, costs less than copper per foot, and installs significantly faster. Two connection methods dominate the residential market: crimp rings and expansion fittings. The tools for each system are different and not interchangeable, so choose your connection method before buying or renting tools.

PEX crimp tools compress a copper crimp ring around the tubing over a brass barbed fitting. The crimp ring squeezes the tubing tightly against the fitting barbs, creating a watertight seal rated for the life of the tubing. Crimp tools come in sizes matching the tubing diameter, with 1/2-inch and 3/4-inch being the most common residential sizes. A combo tool with interchangeable jaws handles both sizes. After each crimp, check it with a go/no-go gauge - a simple metal gauge that verifies the crimp diameter meets code requirements. A crimp that is too loose leaks. A crimp that is too tight can crack the ring over time.

PEX expansion tools (for expansion-type fittings like Uponor/Wirsbo) work on a different principle. The tool expands both the tubing end and a separate expansion ring, then you slide the expanded assembly over a fitting. As the PEX contracts back to its original diameter over the next few seconds, it squeezes the fitting and creates a joint that actually gets stronger over time as the material continues to contract. Expansion fittings are the premium PEX system - more expensive fittings and tools but with fewer flow restrictions because the fitting does not protrude into the tubing bore the way crimp fittings do.

For a single bathroom remodel or a water heater replacement, renting a PEX tool makes more financial sense than buying. Crimp tools rent for $30 to $50 per day from plumbing supply houses and some home improvement stores. Expansion tools cost more to rent ($50 to $100 per day) but the system is faster for larger projects because the expansion happens in seconds. If you are replumbing an entire house or planning multiple plumbing projects over the next few years, owning the tool saves rental costs after the second or third project. A quality crimp tool costs $50 to $100, while expansion tools run $250 to $400 for a manual version or $300 to $500 for a battery-powered model.

Copper Pipe Cutters

Tubing cutters make clean, square cuts on copper pipe without deforming the tube. A standard tubing cutter has a sharp cutting wheel and two rollers. You place the cutter around the pipe, tighten the knob until the cutting wheel contacts the copper, and rotate the cutter around the pipe. After each full rotation, tighten the knob slightly and rotate again. The result is a perfectly round, burr-free cut end ready for soldering or compression fittings. A hacksaw also cuts copper, but it leaves a rougher edge that requires more filing and deburring before you can make a joint.

Mini tubing cutters fit into tight spaces where standard cutters cannot swing a full rotation - behind walls, under sinks, inside vanity cabinets, and near existing fittings where the clearance between the pipe and the surrounding structure is only an inch or two. These compact cutters have a smaller cutting wheel and a reduced body profile. The tradeoff is slower cutting (more rotations per cut) and a limited size range (most mini cutters handle up to 1-inch pipe). Keep both a standard and a mini cutter in your plumbing kit because you will inevitably need to cut pipe in a location where the standard cutter does not fit.

Deburring tools remove the slight inner burr left by the cutting wheel on every cut. This burr is a thin ridge of copper pushed inward during cutting. It restricts water flow, creates turbulence that accelerates erosion corrosion at the joint, and prevents proper flux coverage and solder penetration when soldering. A few twists of a deburring tool (a small reamer that fits inside the cut pipe end) cleans the burr in seconds. Never solder a joint on an un-deburred pipe. Many tubing cutters have a built-in triangular deburring blade that folds out from the body of the tool.

For larger copper pipe (1-inch and above), a ratcheting pipe cutter provides the leverage to cut through thicker-wall tubing without excessive hand force. The ratchet mechanism lets you make incremental cuts in tight spaces where you cannot rotate a standard cutter fully around the pipe. These cutters are more expensive ($30 to $60) than standard models ($10 to $20) but they are essential for working with larger water mains and heating system pipes where wall thickness and pipe diameter make standard cutters impractical.

Soldering Tools and Technique

While PEX has replaced copper in most new residential plumbing, millions of homes still have copper supply lines that occasionally need repair or modification. Soldering (also called sweating) copper joints requires a propane torch, lead-free solder, flux paste, emery cloth, and a flame protector cloth.

The process is straightforward but must be done correctly for a watertight joint. Clean both surfaces (the outside of the pipe and the inside of the fitting) with emery cloth or a fitting brush until the copper is bright and shiny. Apply flux paste to both surfaces. Assemble the joint. Heat the fitting (not the solder) with the torch, moving the flame around the joint evenly. When the fitting is hot enough, touch the solder to the joint - it should melt on contact and wick into the joint by capillary action. A properly soldered joint shows a thin, even ring of solder around the entire circumference.

The most common soldering mistake is heating the solder directly rather than the fitting. The solder must be drawn into the joint by capillary action, which only happens when the fitting itself is hot enough to melt the solder. If you heat the solder directly, it drips onto the pipe surface without flowing into the joint, resulting in a joint that looks soldered from the outside but has gaps and will leak under pressure.

Always drain the pipe completely before soldering. Water inside the pipe absorbs heat and prevents the joint from reaching soldering temperature. Even a few drops of water trapped in a horizontal run can prevent a successful joint. Stuff a small piece of white bread into the pipe upstream of the joint to absorb residual water - the bread dissolves when the water is turned back on and flushes away harmlessly.

Flare Tools

Flare fittings join copper, brass, and soft steel tubing for gas lines, refrigeration lines, and high-pressure applications where soldering is impractical or not permitted. A flaring tool shapes the tube end into a cone (typically at a 45-degree angle) that mates precisely with a flare fitting nut. When the nut is tightened against the fitting body, the cone compresses against a matching seat in the fitting, creating a metal-to-metal seal that does not require solder, adhesive, or thread sealant.

A flaring bar (also called a flaring block) holds the tubing at the exact height for a correct flare. The yoke, which carries the cone-shaped forming tool, screws down onto the tube end to create the flare. Proper technique matters for a leak-free connection: cut the tubing perfectly square with a tubing cutter, deburr both the inside and outside of the cut end, slide the flare nut onto the tubing before flaring (you cannot add it after the flare is formed), clamp the tubing in the bar with the correct amount protruding above the bar face, and screw the yoke down smoothly without forcing it. An uneven flare, a cracked flare, or a flare with the wrong angle will leak.

Double-flare tools create a folded-over flare that is stronger and more resistant to cracking than a single flare. The folded edge provides a thicker sealing surface and distributes the compressive force of the fitting nut more evenly. Most automotive brake lines require double flares, as do many gas applications and high-pressure refrigeration connections. The process adds one step to single-flaring: a separate adapter die forms an initial lip on the tube end before the yoke folds that lip over into the finished 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 (yellow Teflon tape or pipe dope specifically labeled for gas) on all threaded connections. After completing every connection, perform a leak test by brushing the joint with soapy water or a commercial gas leak detector solution and watching for bubbles. Any bubbles indicate a leak that must be corrected before turning the gas supply on. Gas line work may require a permit and inspection in your jurisdiction, so check local codes before starting.

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 permanently around the pipe, creating a code-compliant connection in about 4 seconds. It is the fastest joining method for any pipe material and has become the standard in commercial plumbing because it eliminates open-flame work (no torch permits needed) and produces consistent joints regardless of operator skill.

The press tool and jaws are specific to each fitting brand and pipe material. ProPress (the most common copper system, made by Viega) uses one jaw profile. Viega MegaPress handles black iron and stainless steel with a different jaw. Various PEX press systems have their own jaw profiles as well. Using the wrong jaw on the wrong fitting creates a joint that appears connected but does not seal properly and will fail under pressure. Always verify jaw and fitting compatibility before pressing.

The cost of press tools is the main barrier for homeowners. Professional-grade battery-powered press tools cost $2,000 to $5,000 depending on the brand and included jaw sizes. For a homeowner doing one bathroom remodel or a water heater installation, renting is the only practical option. Some plumbing supply houses rent press tools by the day for $75 to $150, which includes the tool and one or two jaw sizes. The fittings themselves cost more than solder fittings ($3 to $8 per fitting compared to $0.50 to $2 for solder fittings), but the labor savings on large projects with dozens of connections are substantial.

Press fittings have a built-in quality indicator - an unpressed fitting shows a visible gap or a colored dot on the fitting body that disappears when the fitting is fully pressed. This visual indicator makes quality control straightforward: walk the entire job and visually verify every fitting before turning on the water and pressurizing the system. A missed (unpressed) fitting under pressure creates a dramatic and immediate failure, so the visual indicator is a critical safety feature. Some systems also include a "smart connect" feature where an unpressed fitting deliberately leaks a small amount during pressure testing so you can identify and press any connections you missed.

Choosing the Right Connection Method

For new residential water supply lines, PEX with crimp or expansion fittings is the standard choice for most projects. It is affordable, fast to install, and forgiving of minor mistakes. PEX tubing costs about $0.50 to $1.00 per foot compared to $2 to $4 per foot for copper, and the fittings install in seconds rather than the minutes required for soldering each copper joint.

For repairs to existing copper systems, soldering is the traditional approach if you are comfortable with the technique. Press fittings are the modern alternative that eliminates the torch and produces equally reliable joints. If you have more than a few copper joints to make and prefer not to solder, renting a press tool for the day is worth the cost.

For gas lines, use only materials and methods approved by your local code. Black iron pipe with threaded connections is the traditional standard. CSST (corrugated stainless steel tubing) with manufacturer-specified fittings is the modern alternative for flexible gas piping. Flare connections are standard for the final connection to appliances. Never use PEX, copper with solder joints, or PVC for gas lines.

Frequently Asked Questions

Should I Use PEX or Copper for New Water Lines?

PEX for most residential water supply work. It costs less, installs faster, resists freezing better, and does not corrode. Copper is the better choice for exposed locations where appearance matters (like a utility room with visible plumbing) and for hot water lines in some jurisdictions that still require it by local code. PEX cannot be used outdoors where it will be exposed to sunlight (UV degrades the material) or for the first 18 inches from a water heater (too close to the heat source - use copper or brass stubs). Check your local code for any PEX restrictions.

Can I Do My Own Gas Line Work?

In many jurisdictions, homeowners can do gas piping work on their own property with a permit and inspection. The work requires gas-rated pipe and fittings, proper thread sealant (never standard white plumber's tape on gas connections - use yellow gas-rated tape or pipe dope), pressure testing of the completed system, and a leak test on every single connection. If you are not confident in your ability to create leak-free connections, hire a licensed plumber. Gas leaks are life-threatening and can cause explosions. Always check local codes before starting.

What PEX Connection Method Is Best?

Crimp connections are cheaper (lower tool and fitting cost) and work well for most residential applications. A crimp tool and fittings for a bathroom remodel might cost $100 to $150 total. Expansion connections are the premium option - they have better flow characteristics because the fitting does not restrict the tubing bore, and the joint gets stronger over time as the PEX continues to contract. For a whole-house replumb, the choice often comes down to which tool you can rent or afford to buy. Both methods are code-compliant and reliable when installed correctly with verified connections.

Related Reading

• Plumbing Emergency Toolkit
• Soldering Guide
• Wrench Guide