How to terminate a Cat 5 cable with a RJ-45 Crimp Connector

(T-568B wiring standard)


  1. Category 5 or 5E cable comes in twisted or solid wire. Make sure that your RJ-45 connectors are designed for twisted or solid wire as required. Using the wrong type of connector may not work or it might fail in the future. THIS IS VERY IMPORTANT.

  2. Keep the pairs together, this is IMPORTANT as untwisting the wires can result in crosstalk and degraded service. Naturally you have to untwist the pairs to make the connection but do not untwist more than 1/2 inch from the end.

  3. The wires are arranged in pairs. A category 5 or 5E cable has 4 sets of 2 wires or 8 wires total. Typically this is called a 4 pair twisted cable.

  4. If you are new to this, first cut off a few inches of cat 5 cable and then strip back the outer sheath for an inch or so but don't disturb the individual pairs of wires. By inspection, you should be able to see that the wires are in 4 groups (or pairs) of 2 wires each. Bend the wires until you have 4 distinct pairs of wires. Now inspect the colors of each set of wires. You should be able to determine which wire is the "solid" color and which is the "stripe" based upon the colors. Sometimes the stripe is hard to see and so look closely.

  5. If you are color-blind, like me, you may have to have someone tell you what the colors are. I'm red-green color blind (the most common) and I can figure out the colors after knowing they can only be orange, green, blue, or brown. Also what you can do is write the colors on masking tape and wrap the tape around each color. Then pitch the piece of tagged cable in your tool box. Then you can use your tagged cable to help identify the colors.

  6. There is NO need to strip each indiviual wire when working with crimp connectors, the connector will pierce the coating when crimped.
  7. Best time to do this is in normal day light.

Patch Cable Assembly Instructions

1. Skin off the cable jacket approximately 1" or slightly more.
2. Un-twist each pair, and straighten each wire between the fingers.
3. Place the wires in the order of one of the two diagrams shown above. Bring all of the wires together, until they touch.
4. At this point, recheck the wiring sequence with the diagram.
5. Optional: Make a mark on the wires at 1/2" from the end of the cable jacket.
6. Hold the grouped (and sorted) wires together tightly, between the thumb, and the forefinger.
7. Cut all of the wires at a perfect 90 degree angle from the cable at 1/2" from the end of the cable jacket. This is a very critical step. If the wires are not cut straight, they may not all make contact. We suggest using a pair of scissors for this purpose.
7B. Conductors should be at a straight 90 degree angle, and be 1/2" long, prior to insertion into the connector.
8. Insert the wires into the connector (pins facing up and the tab on the bottom side).
9. Push moderately hard to assure that all of the wires have reached the end of the connector. Be sure that the cable jacket goes into the back of the connector by about 3/16".
9. Place the connector into a crimp tool, and squeeze hard so that the handle reaches it's full swing.
  10. Repeat the process on the other end. For a straight through cable, use the same wiring.
  11. Use a cable tester to test for proper continuity.
  • If the cable tester indicates a wiring problem, try re-crimping the connector. If you can't get continuity on all the pins, you will have to replace one or both of the connectors. There is no way to tell which one is bad if you can't see any problems.
  • If you re-terminate a connector, use a ball point pen or some what to mark which end you put a new connector on. It is easy to lose track and have to cut the old connector off and put another on because you can't figure out which one you previously replaced.