| 3Com | 3M | |
| B&B Motor & Control Corp. | Baco | Baird & Tatlock |
| Baldor | Balluff | Balston |
| Balzer, see Balzers | Balzers | Balzers Union |
| Banner Engineering | Barcopac | Barden |
| Barker & Williamson | Barksdale Inc. | Baumer |
| Baumer Electric | Bbc | Beckhoff |
| Beckman Instruments | Belden | Belfab |
| Belling Lee | Belling-Lee | Bellingham & Stanley Ltd. |
| Bendix Dynapath | Berger Lahr | Berkleonics |
| Beta Squared | Bi Technologies | Bimba |
| Binder | Bio-Rad | Bird |
| Bird Electronic | Biscor | Bishop Wisecarver |
| Blomme | Blondelle | Blue Chip |
| Blue White | BOC | Bodine |
| Bodine Electric Company | Boiswood | Bosch |
| Bourns | Bourns Trimpot | BPS |
| Branson | Brecoflex | Brecooflex |
| Briskheat | Britclips | British Telecom (see BT) |
| Brook Control Gear | Brook Crompton | Brooks Instruments |
| Brooks Mfg. Corps | Brown Bouveri | Bruce |
| BSL | BT | BTI |
| Burgess | Burkert | Burket |
| Burndy | Burr Brown | Burrell Pneumatic |
| Buss | Bussman | Bussmann |
| QMS | Qualidyne | Qualiflow |
| Quality Precision | Quartzfab | |
| Ual | UCC | Ul |
| Ulrick Matter | Ultratech | Ulvac |
| Unaxis | Unbranded | Und Lab Inc |
| Unimation | Unimax | Unit Instruments |
| United Electric | Unitrode | Unitta |
| Unknown | Unkown | US Dynamics |
| US Gauge | Ushio | Uuniphase/Cyonics |
| X-Acto | Xycarb Ceramics | Xycom |
| Yamada | Yellow Spring | Yokahama Denki |
| Zellweger Analytics | Ziatech | Zilog |
| Zimmermann | Zitel Corp. | Zurrer |
| aaaaaa |