Quick Answer / Summary: USB 3.0 Type-B is the wide, divided interior version of the classic square B plug – carrying ten pins (five legacy, five SuperSpeed) at 5 Gbps. It appears on USB 3.0 printers, scanners, audio interfaces, and hub upstream ports. Class rules apply as everywhere: 3.0-class cables state ‘USB 3.0’; 2.0 B cables fit the narrow section at 480 Mbps. Match the plug shape to the device socket, then verify the class claim for data-speed-critical devices.
The B plug family is the peripheral side of USB – and its 3.0 variant doubles the pin count inside a visibly wider frame. This page identifies the 3.0 Type-B at a glance, lists its device classes, and applies the family’s class rules to cable buying.
Identifying USB 3.0 Type-B
Classic USB-B: square-ish with beveled top corners, single chamber. USB 3.0 Type-B: visibly taller with a divided interior – the original B section plus a SuperSpeed section stacked above. Devices: USB 3.0 printers and scanners, audio interfaces (the B family’s natural home), USB hubs’ upstream ports, and industrial peripherals. The shape rules the purchase: the 3.0 plug does not fit 2.0 B sockets; 2.0 plugs fit 3.0 sockets at 2.0 speed.
Device Classes and Why B Persists
Printers/scanners: B remains the default peripheral plug even in modern models. Audio interfaces: B (and increasingly C) carries multichannel streams; 3.0-class wiring matters for high-channel-count units. Hub upstreams: B 3.0 feeds bus-powered hubs their data and power. The B family persists because device-side C adoption lags peripherals – and because the plug’s retention is excellent.
Class Rules for B Cables
A 3.0 B cable states ‘USB 3.0’ and carries the ten-wire class; 2.0 B cables (four-wire) fit and run at 480 Mbps. For printers, 2.0 speed is irrelevant – page data fits easily. For audio interfaces and scanners at depth, the class claim matters: verify with a device-side throughput test rather than a listing’s silence.
Buying Notes
Match the socket shape first (2.0 B vs 3.0 B vs Mini/Micro-B variants); state the class when speed matters; prefer molded strain relief on the B shell (its mass levers cheap units); length per the 3.x passive limit (~2-3 m) for data-critical duty. Keep one spare B cable per critical peripheral – the B family will outlast many of the devices it serves.
Type-B Family Reference
| Variant | Shape | Pins | Typical Devices |
|---|---|---|---|
| USB-B 2.0 | Square, beveled | 4 | Older printers, hubs |
| USB-B 3.0 | Tall, divided interior | 10 | USB 3.0 printers, audio interfaces |
| Mini-B | Small trapezoid | 5 | Legacy cameras, GPS |
| Micro-B 3.0 | Wide, divided | 10 | Portable drives |
Real-World Application Scenarios
An office replaces a frayed printer cable with the correct 3.0 B unit after a shape check; a studio verifies its interface’s class and stops a mystery dropout; a bench keeps one spare per B-device class and never improvises with 2.0 units again.
Recommended Internal Resources
Editorial Note: Cable context sits in USB Cables and Cords; audio-side products in Audio Cables and Jacks; printer-adjacent bridges in USB Data Transfer Cables.
Frequently Asked Questions (FAQ)
Q: What is USB 3.0 Type-B?
A: The wide, divided-interior version of the square B plug – ten pins at 5 Gbps – used on USB 3.0 printers, scanners, audio interfaces and hub upstreams.
Q: Can a USB 2.0 B cable work in a 3.0 B socket?
A: Yes, at 2.0 speed (480 Mbps). Fine for printers; insufficient for high-channel audio or fast scanners.
Q: Does my printer need a USB 3.0 B cable?
A: No – printer data fits 2.0 speed easily. Any correct-shape B cable works; 3.0 class matters for audio interfaces and fast scanners.
Q: Why is the B plug still used when C exists?
A: Peripheral-side adoption lags host-side, and B’s retention is excellent. The family persists on printers, interfaces and industrial devices.