Premier Manufacturer
Technical Differences
An unshielded RJ45 plug has a clear plastic housing and exposes the twisted-pair wires (as shown).
It simply guides each conductor to the gold contacts, without any metal surrounding the plug. As a result, its only protection against noise comes from the cable’s twisting; the plug provides no extra EMI shielding. Unshielded plugs are inexpensive and easy to use, making them ubiquitous in home and office networks. In contrast, a shielded RJ45 plug has a metal shell (usually tin, nickel, or zinc-plated brass) enclosing the plastic insert. The image below shows a metal-bodied plug: this conductive housing acts as a Faraday cage, shunting interference to ground.
Shielded plugs must be crimped to the cable’s drain wire so the shield remains continuous; they dramatically reduce EMI/RFI and crosstalk in noisy environments. In short, unshielded connectors are simple plastic parts built for affordability and ease of installation. In contrast, shielded connectors incorporate a metal shell and grounding contacts to preserve signal integrity in high-speed or high-interference settings.
A shielded RJ45 plug (shown) wraps the plug’s contacts in a metal jacket.
This housing is bonded to the cable’s foil, braid, and the equipment ground. Connecting the cable’s shield to the jack prevents stray electrical noise from reaching the data pairs. Typical shielded plugs are Cat6a/Cat7-rated, supporting 10Gbps (500MHz) with very low alien crosstalk. Unshielded RJ45 plugs, by contrast, have plastic bodies and are rated only by cable category (Cat5e, Cat6, etc.). Importantly, a shielded connector on a UTP cable yields no benefit, and a UTP plug on a shielded cable breaks the shield continuity. In practice, manufacturers design each connector to match specific cable constructions (e.g. stranded vs solid conductors, 23 AWG vs 24 AWG) and performance categories.
Use Cases Across Industries
- Industrial Automation: Heavy machinery and factory floors are rife with motors and welders that generate EMI. In such environments, shielded connectors are essential. Industrial RJ45 plugs (often IP65/67-rated) ensure that fieldbus and Ethernet cables maintain their shield and meet standards like Profinet or EtherNet/IP immunity. Vendors specifically market metal-bodied RJ45 connectors for rugged environments.
- Data Centres: Modern data centres deploy high-bandwidth cabling (10G/25G over Cat6a/Cat7). Although data halls are relatively controlled environments, many installations still use shielded Cat6a or Cat7 cables to maximise performance and reduce crosstalk in dense cable bundles. In practice, patch panels in data centres may use FTP/UTP pendants or mix STP and UTP patch cords depending on aisle configuration. However, for standard office-grade data centres, plain UTP usually suffices because of structured cabling best practices.
- Enterprise Networks (Office/Commercial): Typical office LANs favour UTP wiring because it’s cheaper and easier to install. UTP RJ45 plugs meet the needs of most corporate networks, as day-to-day office equipment rarely generates severe EMI. Some high-end installations (e.g. financial trading floors or audio/video studios) may specify shielded links, but this is the exception.
- Residential Setups: Home networks almost always use UTP (Cat5e/Cat6) with unshielded plugs. A home rarely needs shielded cable unless the homeowner has specialised audio/video gear or equipment racks near noisy appliances. A standard unshielded RJ45 plug is the norm for everyday streaming and gaming.
In summary, unshielded RJ45 plugs (and UTP cable) dominate clean electrical environments (homes, offices, most data centres). In contrast, shielded RJ45 plugs are reserved for harsh or noise-sensitive settings (industrial plants, broadcast, military, medical).
Pros and Cons of Each Type
| Feature | Shielded (STP) Plug | Unshielded (UTP) Plug |
|---|---|---|
| EMI Protection | Provides a full metal shield around contacts – greatly reduces EMI/RFI. Essential in noisy environments. | No metal shield. Susceptible to outside interference; relies only on cable twist. |
| Installation | More complex: you must fold cable shield back, crimp down the ground tab, and ensure shield continuity. Often stiffer connectors. | Simple crimp: just insert wires and crimp. No extra grounding or bonding needed. Generally more flexible cable. |
| Grounding | Requires grounding at patch panel/equipment to work correctly. Otherwise shield is ineffective. | No grounding – nothing to ground. |
| Cost | Higher cost due to metal parts and plating. Shielded plugs can be 2–3× the price of UTP versions. | Low-cost, widely available. Bulk packs of plastic plugs are inexpensive. |
| Bandwidth/Performance | Supports up to cable’s rated bandwidth and maintains signal quality in high-speed links. Shield prevents alien crosstalk, helping meet 10GbE specs. | Same Cat rating potential, but EMI or crosstalk can limit real-world performance under stress. UTP plug itself doesn’t add bandwidth protection. |
| Durability | Metal housing is robust (better kink and crush resistance). Often designed for rugged use. | All-plastic housing is less rugged. Fine for desktop or short runs only. |
Each plug choice has trade-offs: STP connectors offer noise immunity and mechanical strength, at the expense of extra installation steps and cost. UTP connectors minimise expense and simplify installation (since no shield bonding is needed) but forego any built-in EMI defence.
Compatibility with Cable Types
RJ45 plugs must match the cable type. Generally, use shielded plugs only with shielded cables and unshielded plugs with unshielded wires. The TrueCable technical guide sums it up: “If the cable is shielded, you will want to use shielded RJ45 connectors; if the cable is unshielded, use unshielded connectors.” Using a shielded plug on UTP wire gives no benefit (it often won’t fit properly), and using a UTP plug on FTP cable breaks the foil continuity.
Connectors are also rated by category. Always pick a plug rated for the same or higher category as the cable. For example, Cat6a cables (500 MHz, 10 Gbps) require Cat6a-rated connectors to meet spec. Many Cat6A/7 plugs are designed with larger pass-through holes and internal spacers to handle thicker conductors. Notably, modern shielded cables like Cat7 or S/FTP Cat6a carry multiple layers of foil/braid; their RJ45 terminations must be shielded and designed for those constructions. In practice, installers should verify that the plug’s spec (Cat5e, 6, 6a, etc., shielded vs unshielded, solid/stranded cable) exactly matches the cable. Following this ensures the end-to-end link can achieve the cable’s rated bandwidth.
Regional Purchasing Trends
Market analyses indicate North America is the largest market for Ethernet patch cabling. One industry report forecasts that the NA region will dominate RJ45 patch cable consumption through 2030, driven by rapid data-centre build-out and office upgrades. In practice, the North American market overwhelmingly favours UTP solutions for mainstream use, given their lower cost and ease of deployment. Europe represents a similarly large share of cabling demand. Many European installers emphasise shielding for high-end projects – for instance, EN/ISO standards guide shielded cabling for data centres and industrial facilities. While up-to-date region-by-region statistics are scarce, anecdotal evidence suggests that most consumer and office purchases in both regions are unshielded. In contrast, many European enterprise projects might specify FTP/STP cable and plugs for EMC compliance. In short, UTP patches dominate volume in both markets, but Europe’s commercial segments often have more robust shielded cabling mandates.
Best Practices for Plug Selection
- Match Plug to Environment: Use shielded RJ45 plugs whenever the network run is subject to interference (electrical equipment, long open runs, industrial spaces). Metal plugs with grounded shields are best in EMI-prone settings (e.g., radio towers, manufacturing). For routine office or home LANs, unshielded plugs are usually fine and simplify installation.
- Maintain Shield Continuity: If you choose shielded cable, ensure every connector and panel is shielded. TrueCable notes that shielded plugs without patch panels or jacks defeat the purpose. In other words, don’t mix shielded and unshielded components on the same link.
- Proper Grounding: Always bond the cable shield to earth ground at one end (typically the patch panel side). The cable drain wire must be securely crimped under the plug’s ground tab. Failing to ground a shielded connector can make interference worse.
- Respect Category Ratings: Use a connector rated for at least the cable’s category. For a Cat6a line, use a Cat6a plug; for Cat5e, a Cat5e plug. This ensures the plug’s internal geometry won’t bottleneck the signal bandwidth.
- Wire Strain Relief: Use the plug’s boots or strain-relief collars to protect the termination if available. Many outdoor/industrial plugs are IP-rated (IP65/67) and include seals—these should be used per the instructions to maintain ingress protection.
- Installation Technique: Strip cable jackets carefully to avoid nicking conductors or shields. For shielded plugs, peel back the foil braids evenly and crimp the ground collar first (Truecable advises crimping the ground collar before the contacts). Confirm the wire order with a tester.
- Future-Proofing: If you expect an upgrade to 10GbE or higher, lean toward Cat6a (often shielded) components now. Even if EMI isn’t an issue today, an extra shield won’t hurt in the long run. Conversely, avoid shielded plugs unless you have shielded cable – they add cost and bulk unnecessarily otherwise.
Major Manufacturers and Romtronic
Many established connectivity brands offer STP and UTP RJ45 plugs for various applications. TE Connectivity (Amphenol) provides a wide range of RJ45 connectors: for example, TE’s Cat6a shielded plug can terminate 10 Gbps cable without tools and handles 500 MHz performance. Amphenol LTW supplies industrial-grade RJ45 modules that meet IP67 waterproof standards and support Cat6a (10Gbps) performance. Weidmüller and Phoenix Contact also have industrial Ethernet plugs and jacks designed for factory automation; Weidmüller notes their pre-assembled RJ45 connectors “ensure reliable data transmission” in harsh networks.
Companies like Panduit, Molex, Siemon, and Belkin offer tool-less and crimp-style RJ45 plugs (shielded and unshielded) for Cat5e/6/6A patch cables in the commercial office space. A number of speciality brands (Platinum Tools, L-com, etc.) sell popular “EZ-RJ45” or pass-through plugs that simplify field terminations.
At Romtronic, we focus on OEM and ODM cable assembly services rather than manufacturing branded plugs. Our core strength lies in producing customised Ethernet cables and wire harnesses, which we supply to customers in over 80 countries. While we use industry-standard RJ45 connectors sourced from trusted vendors, what sets us apart is our ability to deliver fully assembled, ready-to-use solutions tailored to the unique needs of telecom, industrial, and medical applications. We offer custom lengths, specialised materials—such as flame-retardant or UV-resistant cables—and in-house wiring expertise. Unlike plug and connector manufacturers like TE or Amphenol, Romtronic is a contract manufacturer providing complete, made-to-order cabling solutions.
Sam Wu is the Marketing Manager at Romtronic, holding a degree in Mechatronics. With 12 years of experience in sales within the electronic wiring harness industry, he manages marketing efforts across Europe. An expert in cable assembly, wiring harnesses, and advanced connectivity solutions, Sam simplifies complex technologies, offering clear, actionable advice to help you confidently navigate your electrical projects.
