How to Cut and Crimp PEX Tubing Like a Pro
About This Project
This guide provides comprehensive, step-by-step instructions for properly cutting PEX tubing, installing a copper crimp ring and a barbed fitting, and securing the connection using a PEX crimping tool to create a durable, leak-proof joint. The process concludes with a critical quality check using a go/no-go gauge.
Best for experienced DIYers and homeowners with some experience with basic plumbing knowledge and familiarity with power tools. Requires HDX Over the Glass Indoor Safety Glasses VS-265.
Tools & Materials
SharkBite 1/4 in. to 1 in. PEX Pipe and Tubing Cutter with Replaceable Blade 25880A
Apollo 1/2 in. and 3/4 in. PEX-B Crimp Tool 69PTKH0014C
General Tools 10 in. Locking Contour Gauge with Extended Pins 834X
PLUMBFLEX 1/2 in. x 1000 ft. Red PEX-B Tubing Oxygen Barrier Radiant Heating Pipe PFR-R121000NW
PLUMBFLEX 3/8 in. Brass PEX x PEX 90-Degree Elbow Barb Pipe Fitting (10-Pack) 3810PXLN
Apollo 1/2 in. Copper Crimp Ring (25-Pack) APXCR1225PK
SharkBite 1/4 in. to 1 in. PEX Pipe and Tubing Cutter with Replaceable Blade 25880A
SharkBite pro-grade PEX cutter is designed to safely cut PEX pipe straight and flat. Replaceable V-shaped blade easily cuts PEX pipe and maintains roundness of the pipe. Specially designed flats on the
Apollo 1/2 in. and 3/4 in. PEX-B Crimp Tool 69PTKH0014C
The ApolloPEX Combo PEX Copper Crimp Ring Tool is a 2-in-1 tool designed to secure 1/2 in. and 3/4 in. copper crimp rings (not included) into place within PEX piping systems. There are no loose components,
General Tools 10 in. Locking Contour Gauge with Extended Pins 834X
The 834 x ANGLE-IZER 10 in. Locking Contour Gauge with extra-long pins can duplicate any shape instantly. Just Press, Lock and Copy. This profile gauge creates an instant template for curved and odd shaped
PLUMBFLEX 1/2 in. x 1000 ft. Red PEX-B Tubing Oxygen Barrier Radiant Heating Pipe PFR-R121000NW
Oxygen barrier (EVOH) is a strong and flexible cross-linked polyethylene tubing with superior temperature and pressure ratings. Useful in commercial and residential hydronic radiant heating applications.
PLUMBFLEX 3/8 in. Brass PEX x PEX 90-Degree Elbow Barb Pipe Fitting (10-Pack) 3810PXLN
The PEX Barb Elbow (10-Pack) is an easy to install, low cost solution to connect PEX Pipe. PEX Barb fittings are compatible for potable water distribution and hydronic heating applications. These PEX fittings may be used with the stainless steel clamp system or the copper crimp ring system (both sold separately). These PEX Barb fitting range offers a wide variety of Fittings, Manifolds, Valves, clamp rings, crimp rings and tools in various sizes to help complete your next plumbing project.
Apollo 1/2 in. Copper Crimp Ring (25-Pack) APXCR1225PK
The Apollo PEX 1/2 in. Copper Crimp Ring (25-Pack) is simple to install and is designed for use with PEX pipe and barb fittings (not included). Made from copper for durability. Requires a crimping tool
Steps
Gather Tools and Materials
2 minsBefore beginning any work, gather all the necessary tools and materials in your workspace. This includes your roll of PEX tubing, the appropriate PEX crimp fittings (e.g., couplings, elbows, tees), and a supply of copper crimp rings matching the tubing diameter. Your essential tools will be a dedicated PEX tubing cutter, a PEX crimping tool calibrated for your ring size, its corresponding go/no-go gauge, and safety glasses for eye protection. Laying everything out ensures an efficient workflow and prevents interruptions.
Watch: Prepare the Pipes
Cut the Tubing
1 minMeasure the desired length of your PEX tubing and make a clear mark. Place the PEX tubing cutter on the mark, ensuring it is perpendicular to the pipe. Squeeze the handles of the cutter firmly to slice through the tubing. A proper PEX tubing cutter is designed to make a perfectly square and clean cut. Avoid using hacksaws, utility knives, or shears, as they can create burrs, deform the tubing, or result in an angled cut, all of which compromise the seal and can lead to future leaks.
Watch: Cut the PEX-A Tubing
Slide on Crimp Ring
30 minsTake one copper crimp ring that matches the diameter of your PEX tubing. Inspect the ring to ensure it is perfectly round and free of any dents or damage. Slide the crimp ring over the freshly cut end of the PEX tubing. The ring should slide on easily and move freely along the pipe.
Watch: Position the Crimper
Insert Fitting into Tubing
30 minsSelect the correct PEX crimp fitting for your connection. Hold the PEX tubing firmly and push the barbed end of the fitting straight into the opening. Apply firm, steady pressure to insert the fitting until the PEX tubing makes contact with the shoulder or base of the fitting. You must ensure the tubing is pushed all the way on; any gap between the tubing's end and the fitting's shoulder will result in a failed connection.
Watch: Connect the Pipe to the Fitting
Crimp the Ring
1 minSlide the copper crimp ring down the tubing until it is positioned over the barbed section of the fitting. The correct placement is critical: the edge of the ring should be between 1/8-inch and 1/4-inch from the end of the PEX tubing. Do not let the ring touch the fitting's shoulder. Open the jaws of the PEX crimping tool and place them squarely over the ring, ensuring the tool is perpendicular to the pipe. Squeeze the handles of the crimper completely until the tool's mechanism fully closes and bottoms out. You will feel a distinct stop. Release the handles to remove the tool.
Watch: Connect and Crimp PEX Tubing
Verify Crimp with Go/No-Go Gauge
1 minThis is the final and most important quality control step. Take your go/no-go gauge. First, attempt to slide the 'Go' slot over the compressed ring. It should fit snugly. Next, attempt to slide the 'No-Go' slot over the ring. It should NOT fit. If the 'Go' slot does not fit, the ring is under-crimped. If the 'No-Go' slot fits, the ring is over-crimped. In either case of failure, the connection is bad and must be redone. Use a special ring-cutting tool or carefully cut the ring off with a rotary tool, remove the fitting, and start over from Step 2 with a new piece of tubing, a new ring, and a new fitting.
Watch: Check CrimpCommon Problems
Damaged O-rings cause leaks if PEX isn't inserted straight.
Solution: Ensure the pipe is pushed in straight to avoid damaging the internal O-ring.
Fittings without stiffeners can cause PEX tubing to collapse during crimping, leading to leaks.
Solution: If a fitting does not have a pre-installed stiffener, one must be inserted into the PEX tubing before making the connection.
An improper or angled cut can compromise the seal and lead to leaks.
Solution: To avoid this issue: Be mindful of this warning and take appropriate precautions.
PEX tubing not fully seated in the fitting, leading to leaks.
Solution: A distinct click or a hard stop indicates the pipe is fully seated in the fitting.
Do not use any lubricants or sealants on push-to-connect fittings; they are designed to seal on their own.
Solution: To avoid this issue: Be mindful of this warning and take appropriate precautions.
Leaky connections due to insufficient pipe insertion.
Solution: Ensure the fitting is pushed all the way into the pipe so the pipe end is flush with the fitting's shoulder.
Difficulty knowing when PEX tubing is fully inserted into the fitting.
Solution: There will be resistance when you reach the proper depth.
Frequently Asked Questions
Why is using a go/no-go gauge so critical after crimping PEX, and what does it tell me?
The go/no-go gauge is essential for ensuring your crimp connection meets industry standards and is leak-proof. The 'go' side should fit over the crimp ring, and the 'no-go' side should not. This confirms your crimp is properly sized and secure, preventing costly leaks down the line.
What are the most common mistakes beginners make when crimping PEX tubing, and how can I avoid them?
Common mistakes include not cutting the tubing squarely, placing the crimp ring too far from the end of the tubing, or failing to use the go/no-go gauge. To avoid these, ensure clean, square cuts, position the crimp ring about 1/8 inch from the end of the tubing and over the barb, and always verify your crimp with the gauge.
The materials list both PEX-A and PEX-B tubing. Does the type of PEX tubing (A or B) affect how I use copper crimp rings?
While copper crimp rings primarily use barbed fittings that are compatible with PEX-B and PEX-C, they can also be used with PEX-A tubing. The crimping method itself remains the same for all PEX types when using barbed fittings and copper crimp rings, but PEX-A is also commonly used with expansion fittings.
How accurate is the 'beginner' difficulty rating for this project, and what's a realistic time estimate for a first-timer to get a good crimp?
The 'beginner' rating is accurate as the steps are straightforward once understood, but practice is key. For a first-timer, expect each connection to take 10-15 minutes initially as you get familiar with tool handling and positioning. With a few successful crimps, your speed and confidence will quickly increase.
This project uses copper crimp rings. Are there other types of PEX connection methods, and why might I choose crimp rings for my project?
Yes, other PEX connection methods include stainless steel cinch clamps, PEX expansion fittings (primarily for PEX-A), and push-to-connect fittings. Copper crimp rings are a popular choice because they are cost-effective, create a very strong, permanent seal when done correctly, and require minimal specialized tools beyond the crimper and gauge.
My go/no-go gauge either won't slide *on* the crimp ring, or it slides *past* the crimp ring. What does this indicate, and how do I fix it?
If the 'go' side won't slide onto the crimp, the connection is likely over-crimped, requiring you to cut it out and re-do it. If the 'no-go' side slides over, it's under-crimped and potentially loose. You may try to re-crimp with the tool or, to be safe, cut out the connection and start fresh.
