Why Your Cat6A Crimps Keep Failing (And How to Fix Them)

The Quick Answer

If you're moving from Cat6 to Cat6A, everything about your termination process needs to change. The cable is thicker, the conductors are bigger, the separator is bulkier, and the connectors are a completely different size. Treating Cat6A like "slightly bigger Cat6" is where most installers go wrong.

Let's walk through each of the three failure points, why they happen, and exactly what to do instead.

Why Cat6A Is Different from Cat6

Cat6 and Cat6A cables look similar on the outside, but Cat6A is built to a much tighter specification. It supports 10-Gigabit Ethernet at the full 100-meter distance and operates at frequencies up to 500 MHz, double what Cat6 is rated for. To hit those numbers, Cat6A cable is physically larger in almost every way.

The key numbers for termination are the outer jacket diameter and the separator size. Cat6A's jacket is roughly 25-30% thicker than Cat6. The internal separator is bigger, stiffer, and harder to trim. These differences mean Cat6 connectors literally do not fit Cat6A cable, and Cat6 crimp dies cannot properly close a Cat6A connector.

Mistake #1: Using Cat6 Connectors on Cat6A Cable

This is the most common Cat6A crimping mistake. Installers who have been terminating Cat6 successfully assume they can use the same connectors on Cat6A. The conductors are technically the same gauge (23 AWG in most cases), so it seems like it should work. It doesn't.

Why it fails

• The jacket won't fit. Cat6A's outer diameter is 7.5-8mm. Cat6 connectors are designed for 6mm cable. The jacket physically cannot enter the strain relief area of the connector.
• The separator blocks the wires. Cat6A's larger separator takes up more internal space. Even after trimming, the remaining bulk prevents the conductors from aligning properly inside a Cat6 connector's wire channels.
• The conductors can't seat fully. Because of the space taken up by the separator and the tighter tolerances inside a Cat6 connector, the individual wires may not reach the contact blades deep enough for a reliable connection.

The fix

Use connectors specifically rated for Cat6A cable. The ezEX48 Cat6A is purpose-built for Cat6A's larger diameter and separator. For shielded Cat6A installations, the Cat6A/7 Shielded Connector handles both the larger cable size and provides full EMI protection for 10-Gigabit environments.

Mistake #2: Wrong Strip Length

Strip length is one of those things that works fine on Cat5e and Cat6 without much thought. You strip about an inch, fan the wires, and crimp. Cat6A is less forgiving because the separator changes the equation.

Why it fails

• Too short (under 1 inch): After trimming the separator, there isn't enough exposed conductor length to reach all the way to the contact blades inside the connector. You'll get open pins or intermittent contacts on your wire map test.
• Too long (over 1.5 inches): The jacket doesn't reach the strain relief clamp inside the connector. The crimp will hold the wires in place, but there's no mechanical grip on the jacket itself. A light tug on the cable can pull the termination apart.
• Inconsistent strip length: Even if your average is right, variation from one termination to the next creates unpredictable results. Some will pass, some won't, and you'll spend time troubleshooting instead of terminating.

The fix

Strip approximately 1.25 inches (about 32mm) of jacket. Use a cable stripper with an adjustable depth stop so you don't nick the conductors underneath. After stripping, trim the separator flush with the jacket edge. Untwist and arrange the pairs, then trim the conductors to the correct insertion length for your specific connector model.

With pass-through connectors like the ezEX48, you have the advantage of seeing the wires emerge from the front of the connector before crimping. If any wire is short, you'll see it before you commit to the crimp.

Mistake #3: Wrong Crimp Tool

This mistake is expensive. Crimp tools look similar, and if you've been crimping EZ-RJ45 Cat6 connectors all day, it's easy to grab the same tool when you switch to Cat6A ezEX connectors. The result is a destroyed connector and wasted time.

Why it fails

• Die geometry mismatch. EZ-RJ45 connectors and ezEX connectors have different external dimensions. The crimp die in an EZ-RJ45 tool is shaped for the EZ-RJ45 connector body. When you put an ezEX connector into that die, it applies force in the wrong places.
• Crushed connector housing. The most common result is a visibly deformed connector. The housing cracks or warps, the contact blades misalign, and the termination is useless.
• Trim blade position. Pass-through crimp tools have a blade that trims the excess conductor wire flush with the connector face. The blade position differs between EZ-RJ45 and ezEX tools. The wrong tool either doesn't trim at all or cuts in the wrong spot.

The fix

Match the tool to the connector. For ezEX48 Cat6A connectors, use either the EzEX Crimp Tool or the PTS PRO Universal Crimp Tool. The EzEX Crimp Tool is purpose-built for the entire EZ-RJ45 and ezEX connector family. The PTS PRO handles EZ-RJ45, ezEX, and standard connectors with a universal die set.

Correct Connector and Tool Pairings for Cat6A

Here's the complete pairing chart so you know exactly which connector goes with which tool for Cat6A work.

The Clamshell EZ-RJ45 Crimp Tool and EZ-RJ45 HD Crimp Tool are not compatible with ezEX connectors. Using them on ezEX connectors will damage the connector.

How to Tell if a Cat6A Crimp Has Failed

A bad Cat6A termination doesn't always look bad from the outside. The connector might appear fine, but the connection inside is marginal or broken. Here's what to look for on a cable tester.

• Open pins on wire map. One or more pins show no continuity. This usually means a conductor didn't seat deep enough to reach the contact blade. Most common with wrong strip length or wrong connector.
• Intermittent pins. The wire map shows a connection, but it flickers or changes when you wiggle the connector. This points to a partial contact where the blade barely touches the conductor.
• High resistance on individual pairs. If your tester measures loop resistance, a marginal connection will show significantly higher resistance on the affected pair compared to the others.
• NEXT failures. Near-End Crosstalk is the primary performance metric for Cat6A. A bad crimp that shifts wire positions inside the connector changes the spacing between pairs at the termination point, causing crosstalk to spike. If your certifier shows NEXT failures within a few dB of the limit, suspect the termination.
• Link negotiates at 1 Gbps instead of 10 Gbps. If both ends of the link support 10GbE but the switch shows a 1 Gbps connection, the cable or termination isn't meeting Cat6A specs. A bad crimp is the first thing to check.

For basic pass/fail wire map testing, the VDV MapMaster 3.0 will catch open and shorted pins. For full Cat6A performance certification including NEXT and return loss, the Net Chaser Ethernet Speed Certifier validates actual throughput up to 10 Gbps.

The "Do It Right" Cat6A Termination Checklist

Follow this sequence every time you terminate Cat6A cable, and you'll eliminate the three common failure points.

1. Confirm your connector is Cat6A-rated. Check the packaging. If it says Cat6 without the "A," it's the wrong connector. Use the ezEX48 Cat6A or Cat6A/7 Shielded.
2. Confirm your crimp tool is compatible. The EzEX Crimp Tool or PTS PRO Universal are the correct tools for ezEX and Cat6A connectors.
3. Strip 1.25 inches of jacket. Use a cable stripper with adjustable depth. Don't nick the conductors.
4. Trim the separator flush with the jacket. Cut the spline or tape wrap cleanly so it doesn't interfere with wire arrangement.
5. Untwist and arrange pairs in T568B (or T568A) order. Keep untwist length to a minimum for best NEXT performance.
6. Insert wires fully into the connector. With pass-through connectors, verify all 8 conductors emerge from the front in the correct order before crimping.
7. Seat the jacket into the strain relief area. The jacket should extend past the strain relief clamp inside the connector.
8. Crimp with the correct tool. Complete the full ratchet cycle. Do not release early.
9. Test every termination. Run a wire map test at minimum. For Cat6A jobs, run a full performance certification.

Recommended Products for Cat6A Termination

These are the connectors, tools, and testers that are purpose-built for Cat6A work. Using the right combination eliminates the three failure points covered in this article.

Related Articles

• Cat6 vs Cat6A: What's the Difference?
• How to Crimp an RJ45 Connector
• EZ-RJ45 vs ezEX Connectors: Which Do You Need?