Male USB B: The Square 4-Pin Connector Explained
The male USB B connector is the squarish plug that fits the B ports on printers, scanners, external audio interfaces, and a lot of lab and industrial equipment – the device end of the standard A-to-B cable. It is one of the most reliable connectors in business equipment, and understanding its shape, its pins, and the difference between the USB 2.0 and 3.0 B versions makes identification and ordering simple. This guide is a reference for the male USB B: what it looks like, the pins it carries, the devices that use it, and how to choose the cable from its B end.
Quick Answer / Technical Summary
A male USB B connector is the squarish plug that inserts into a USB-B port on a device – the device end of the standard A-to-B printer cable. The USB 2.0 B male is a tilted square with four contacts (VCC, GND, D+, D-) at 480 Mbps; the USB 3.0 B male is a larger rectangle with an L-shaped tongue and nine contacts at 5 Gbps. It is found on printers, scanners, external audio interfaces, legacy external drives, and lab or industrial equipment. Choose the cable by matching the B male’s version to the device’s B port – the square 2.0 B for most printers, the larger 3.0 B for faster devices.
The USB-B Male at a Glance
The USB-B male is a squarish plug, tilted on its corners, that fits the matching square B port on the device. It is the device-side counterpart to the rectangular host A plug – together they form the A-to-B connection. Its shape is distinct enough to recognize without a manual.
When a cable or device is described as having a ‘USB-B male,’ this squarish device plug is meant.
Pins: 4 on 2.0, 9 on 3.0
The USB 2.0 B male carries four contacts – VCC, GND, D+, D- – at 480 Mbps, plus the ground shield tabs. The USB 3.0 B male is larger, a rectangle with an L-shaped tongue, carrying nine contacts at 5 Gbps. The 3.0 B plug will not seat in a 2.0 B port, so the version must match the device.
Counting the pins and noting the tongue separates the 2.0 B from the 3.0 B at a glance.
Devices With a B-Female Port
The B-female port – and thus the B male cable – is standard on printers (the dominant user), scanners, external audio interfaces, legacy external hard drives, and a large share of medical, lab, and industrial controllers. If the device side has a squarish port, a B male cable is the match.
The B port is a long-standing device-side standard, which is why the B male is still a common part on the shelf.
Choosing a Cable From a B-Male End
Start at the device’s B port, confirm its version (square 2.0 vs rectangle-plus-tongue 3.0), and choose the cable whose B male matches – usually an A-to-B with a rectangular A male on the host end. Keep the run within the passive length limit and match the build to the environment.
The B male end is the anchor – match it first and the rest of the cable follows.
Technical Specifications & Performance Benchmarks
| Version | Contacts | Speed | Plug Shape / Typical Device |
|---|---|---|---|
| USB 2.0 B | 4 (+ 2 shield tabs) | 480 Mbps | Tilted square – printer, scanner |
| USB 3.0 B | 9 | 5 Gbps | Rectangle + L-tongue – fast device |
| Fit rule | Match the port | n/a | 3.0 B will not fit a 2.0 port |
| Backward fit | 2.0 B in a 3.0 port | 480 Mbps | Works at the lower rate |
| Do not confuse | mini-B / micro-B | varies | Smaller, different device ports |
Industrial & Enterprise Application Scenarios
- Printer Cable Selection: A printer’s square four-contact B port confirms the USB 2.0 B male – the standard A-to-B cable’s device end.
- Audio Interface: A studio audio interface with a B port takes the matching B male cable to the recording computer for a direct link.
- Lab / Industrial Unit: An instrument with a B port connects over the B male cable, version-matched to the port shape.
- Receiving Check: Inbound B male cables sorted by version – square 2.0 vs rectangle-plus-tongue 3.0 – keep the device-side stock correct.
System Integration & Recommended Connectivity Infrastructure
To build a complete, single-cable workstation or equipment-cabinet connectivity stack, pair these USB cable and connector products with our certified data and power interconnect range:
- adapter series: The adapter series covers the host-side conversion when the B male cable’s A end must reach a USB-C or other non-A host port.
- usb extension cable: A usb extension cable on the host A side adds reach when the B male cable’s run falls short of the computer.
- type c-hub: On a USB-C-only computer, a type c-hub supplies the USB-A port that the B male cable’s A end plugs into.
- audio cable: For the audio devices that use a B male port, the audio cable range covers the analog side of the same recording or studio station.
Frequently Asked Questions (FAQ)
Q: What is a male USB B connector?
It is the squarish plug that fits a USB-B port on a device – the device end of the standard A-to-B printer cable. The USB 2.0 B male is a tilted square with four contacts; the USB 3.0 B male is a larger rectangle with an L-tongue and nine contacts.
Q: Which devices use a male USB B connection?
Printers (the main user), scanners, external audio interfaces, legacy external hard drives, and much medical, lab, and industrial equipment with a USB-B port.
Q: How do I tell a 2.0 B male from a 3.0 B male?
The 2.0 B male is a tilted square with four contacts; the 3.0 B male is a larger rectangle with an L-shaped tongue and nine contacts. The 3.0 plug will not seat in a 2.0 B port, so the version must match the device.
Q: Is a USB-B male the same as a mini-B or micro-B?
No – mini-B and micro-B are smaller, different plugs for compact devices. The standard USB-B male is the square printer plug, and the three are not interchangeable.