| 1933 |
Senior Economisers Limited was incorporated when a few employees of Green's Economisers Limited, including Senior's first Chairman, David Lycett Green, set up in opposition. |
| 1947 |
Senior Economisers Limited became a public company and listed on the London Stock Exchange. |
| 1958 |
Acquired Senior Hargreaves Limited (formerly called Henry Hargreaves & Sons). |
| 1966 |
Senior Economisers Limited changed its name to Senior Economisers (Holdings) Limited. |
| 1970 |
Senior Economisers (Holdings) Ltd was renamed Senior Engineering Group Limited. |
| 1982 |
Senior Engineering Group Limited re-registered as Senior Engineering Group plc. |
| 1983 |
Senior acquired Green's Economiser Group plc. |
| 1991 |
Senior Calorstat SAS (formerly called Calorstat Industries SA) joined the Group. |
| 1992 |
Senior Automotive Bartlett with its operations near Chicago, Illinois, became part of Senior with the acquisition of Flexonics, Inc and its subsidiary Senior Operations (Canada) Limited (formerly called Flexonics Limited). Senior Automotive Crumlin, South Wales, established. |
| 1994 |
Acquired Senior Berghofer GmbH (formerly named Christian Berghofer & Co KG) and Senior Aerospace Metal Bellows (formerly the Metal Bellows business of Parker Hannifin Corp.). |
| 1995 |
Acquisition of the Stainless Steel Products business (now known as Senior Aerospace SSP, based at Burbank, California) and Ermeto-Hydexco SA in France (now known as Senior Automotive Blois and Senior Aerospace Ermeto). |
| 1997 |
Sold the original economiser business upon the commencement of the Industrial disposal programme. Acquired the business of Senior Aerospace Ketema, based in San Diego, California. A South African automotive business is established in Cape Town. |
| 1998 |
Acquired Senior Aerospace Bosman B.V. (formerly called Bosman Powersource Support BV). Gained control of Senior India Private Limited (formerly called Inalsa Flexonics Limited). Acquisition of share capital of Senior Aerospace Jet Products (formerly called Jet Products Corporation). Brazilian automotive business is established. |
| 1999 |
The holding company changed its name from Senior Engineering Group plc to Senior plc. Acquired the entire issued share capital of Senior Flexonics Pathway (formerly called Pathway Bellows Inc.). Acquired Senior Aerospace BWT, Senior Aerospace Bird Bellows, and Senior Aerospace Composites, as part of the purchase of the Aerospace Ducting Division of Cork Industries Limited. |
| 2000 |
A new automotive factory at Olomouc, Czech Republic is built. Strategy implemented to focus the Group primarily on the Aerospace and Automotive sectors. Commenced the disposal of various industrial businesses. |
| 2004 |
Completed the Industrial disposal programme which concluded the re-focusing of the Group as an international manufacturing Group supplying to the original equipment producers in the worldwide aerospace and automotive markets. |
| 2006 |
Acquired Sterling Machine Co., Inc. and Aerospace Manufacturing Technologies, Inc. |
| 2007 |
Acquired Absolute Manufacturing, Inc. |
| 2008 |
Acquired Capo Industries, Inc. |
| 2010 |
Acquired WahlcoMetroflex, Inc. |
| 2011 |
Acquired Damar Machine Company, Weston EU and Weston SEA |
| 2012 |
Sold Senior Hargreaves Limited to M+W Group. Acquired GAMFG Precision, LLC. |
| 2013 |
Acquired Atlas Composites Limited and Thermal Engineering Limited. |
| 2014 |
Acquired UPECA Technologies Sdn. Bhd. |
| 2015 |
Acquired Lymington Precision Engineering (LPE) Limited and Steico Industries Inc. |
| 2019 |
Sold Senior Flexonics Blois SAS, Senior Flexonics Brazil Ltda, and Senior Aerospace Absolute Manufacturing. |
| 2021 |
Completed the divestiture of Senior Aerospace Connecticut. |
| 2022 |
Acquired substantially all of the assets of Spencer Aerospace Manufacturing, LLC. |