I was wondering if I can use a CAT5e keystone jack with CAT6 cable. I am refering to the parts that terminate a cable where it comes out of the wall.

I want to run a 30 ft length of CAT6 but all I have is CAT5e jacks and I don't want to buy any news ones if I don't have to.

I had read somewhere that CAT5e is 100mhz and CAT6 is 200mhz (though I could have sworn CAT6 was 350mhz).

Anyhow any assistance would be appreciated.

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    Yes you can, but you will not have CAT6, but CAT5e wirings. The weakest (slowest) component determines the category – Nikola Dimitrijevic Oct 22 '13 at 14:50

From Wikipedia:

Category 6 cable, commonly referred to as Cat 6, is a standardized cable for Gigabit Ethernet and other network physical layers that is backward compatible with the Category 5/5e and Category 3 cable standards.

You can always use a lower standard cable or jack, but you will be limited by the speeds of the slowest link in the chain.

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  • Ok see that is what I was wondering, whether or not the 5e jacks would impact the speed of the cable since the jack built pretty much the same I would imagine. – ianc1215 Oct 22 '13 at 15:18
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    No, it is not. CAT 6 connectors are different and the they have pins in zig-zag order – Nikola Dimitrijevic Oct 22 '13 at 15:22
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    The only difference between Cat5e and Cat6 is the way the cable is made (Cat6 is more twisted and with better shielding). RJ45 terminators made for Cat5 may not fit Cat6 cable due to the thicker size of copper strand, but the pinouts are the same for both cables. See the diagrams here vs here for a comparison. This site has a good explanation of the differences within the cables. – techturtle Oct 22 '13 at 16:21
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    @Shiro If you have a connection that is Cat6 Jack--Cat6 Cable--Cat5e Jack you will be limited to the speed of the slowest piece, namely the Cat5 jack. To ensure full Cat6 speeds, each piece in the connection has to be to the same standard as all the others. Theoretically, anyway... I'm not sure how much of a difference a single jack can make. But if speed is essential, make sure they all match. – techturtle May 4 '18 at 5:41
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    @techturtle I don't know if I agree that the cat5e Jack will noticeable impact speeds. Electrically, the reason why cat5 is slower than cat6 is that it is less insulated from noise (thickness of cables and shielding). How is a cat5 jack constructed differently than a cat6 jack that a cat5 jack is "slower". I would guess that, electrically, the couple of mm of metal the signal goes through in the jack itself doesn't impact the signal much one way or the other. – Philip Jul 14 '18 at 4:04

I would use cat 6 connectors which cost more than the 5e, assuring me of better speed. Also the wall modular female jacks should be of cat6, just to be sure. Better spend a few extra as you already have invested in cat6 cable. maybe you could sell off the 5e to friends or use them to build wire connectors for single computers/slow devices. goodluck!

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    You aren't going to lose any speed using cat5 connectors on cat6 cable. – imperium2335 Feb 16 '18 at 12:54
  • @imperium2335, yes you most certainly will. This can be verified with just about any fluke networks verisiv or dtx cable analyzer. – Tim_Stewart Mar 26 at 20:32

Yes. The RJ45 plug is standard and may only have a different coating on the pins to make it a Cat6 compatible vs. Cat5. You probably won't receive the same speed as if you were using a Cat6 compatible jack.

Doing it this way also denies the ability to call it a Cat6 network though so if you don't care about verbiage technicalities, you are good to go.

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  • Well this is for my house just to bypass the old CAT5/e in the wall that has not worked well for me. – ianc1215 Oct 22 '13 at 15:19
  • You'll be fine using it. – Travis Oct 22 '13 at 18:36

No. Although I used CAT5e jacks to a CAT6 cable, I couldn't have a connection even if my RJ45 cable tester shown that the pins were connected the right way. The issue was solved when I bought CAT6 jacks. Apparently, no comment about speeds.

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Typically, it's up to the RJ45. From what I've seen, CAT6 RJ45 usually uses an insert to aid in placing the wiring. It's easier to fail sticking a CAT6 cable into a CAT5e RJ45, mostly due to the thicker gauge and the crimping not being strong enough to pierce the insulation.

It's possible, but depends on the quality of the RJ45.

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