How it connects
Plug pushes straight into the jack; a flexible latch tab on one side snaps behind a shoulder to retain it and is pressed to release. Eight blade contacts on the plug face touch spring wires in the jack. Cable is terminated to the plug by crimping.
Male and female halves
This is the male half (plug). The female half is the modular jack (socket/receptacle).
Usually connects to
- RJ45/8P8C female jack on network equipment, a keystone wall outlet or patch panel
- RJ45 female coupler
Common sizes
- One 8P8C interface: about 11.7 mm wide, with 8 contacts on roughly 1.02 mm pitch.
- Cable versions cover approximately 22–26 AWG; one Cat5e example accepts 24–28 AWG. Match insulation diameter, cable diameter and solid/stranded construction to the plug.
- Cat5e/Cat6/Cat6A, round/flat cable, shielded/unshielded and pass-through/standard versions share the mating format.
Where it is used
Ethernet LAN patch cabling and computer networkingStructured building cablingPoE devices, including IP cameras and VoIP phonesTelephony/ISDNSerial consoles
Variations
- Clear-plastic unshielded UTP
- Metal-shell shielded STP/FTP for shielded cable
- Pass-through/EZ
- Cat5e
- Cat6/Cat6A, often with load bar
- Strain-relief/snagless boot
- Field-terminable
How to recognise it
Clear or shielded rectangular plastic plug about 11.7 mm wide on the end of a cable, with eight gold blade contacts in slots on the front face and a single flexible latch tab on the opposite side; often a colored strain-relief boot.
Often confused with
| Confused with | How to tell them apart |
|---|---|
| RJ11/RJ12 (6P2C/6P4C/6P6C) plug | 6-position plug is narrower (~9.6 mm) with 2-6 contacts; RJ45 is wider with 8 contacts. |
| 8P8C keyed / RJ48 or RJ45S (keyed modular) | Keyed variants have an extra tab on the plug side; standard RJ45 Ethernet plugs are unkeyed apart from the latch. |
| Cat6/Cat6A modular plug | Same mating face; Cat6 plugs usually have a wire load bar/staggered wire layout. Category is a performance rating, not a different interface. |
| RJ11 / 6P2C / 6P4C plug | Narrower (about 9.7 mm), 6 positions with 2-4 contacts. |
| RJ48 / 10P10C or keyed 8P8C | RJ48 uses the same 8P8C body; 10P10C is wider with 10 contacts; keyed variants have an extra tab. |
Also called
RJ45 plugRJ-45 connector8P8C modular plugCat5e Ethernet plugIEC 60603-7 plugUTP modular plugnetwork connector
Good to know
'CAT5e' is a cable/performance category and does not change the mating interface; all 8P8C plugs mate with 8P8C jacks. Strictly, 'RJ45' was a telephone registered-jack spec, but in common use it means the 8P8C Ethernet connector. Images agree with this.
Related connections
Design with real parts
Crafti checks which parts connect, right in your browser.