| Name | Company Number | Date Appointed | Rating |
|---|
| Name | Company Number | Date Appointed | Date Resigned | Rating |
|---|---|---|---|---|
| Boss Oil Tools Ltd | SC173385 | 21/10/1998 | 24/11/2000 | Dissolved |
| DARRON OIL TOOLS LIMITED | 04934332 | 20/10/2003 | 11/02/2016 | Not Trading |
| DARRON TOOL AND ENGINEERING (SHEFFIELD) LIMITED | 00967870 | 24/10/2003 | 11/02/2016 | Gold |
| REDBACK DRILLING TOOLS LIMITED | SC154774 | 01/01/1999 | 30/03/2001 | Bronze |
| SCHOELLER-BLECKMANN (UK) LIMITED | 02819214 | 23/04/2015 | 11/02/2016 | Not Trading |
| SCHOELLER-BLECKMANN DARRON (ABERDEEN) LIMITED | SC411832 | 23/11/2011 | 05/11/2015 | Gold |
| SCHOELLER-BLECKMANN DARRON LIMITED | SC145802 | 21/11/1995 | 05/11/2015 | One Red Flag |
| SCHOELLER-BLECKMANN OILFIELD EQUIPMENT (UK) LIMITED | 03240818 | 02/05/2002 | 11/02/2016 | Silver |
| TECHMAN ENGINEERING LTD. | 02458616 | 01/10/2008 | 23/02/2009 | Amber |
| TECHMAN ENGINEERING LTD. | 02458616 | 01/10/2008 | 11/02/2016 | Amber |
| TECHMAN PRECISION ENGINEERING LIMITED | 06698408 | 12/11/2008 | 11/02/2016 | Dissolved |
| TECHMAN PRECISION ENGINEERING LIMITED | 06698408 | 12/11/2008 | 11/02/2016 | Dissolved |