ABS - American Bureau of Shipping

Krefeld - Forging Facility and Process Approval[EN]
Witten - Foundry Facility and Process Approval[EN]
Witten - Rolled Bars - Machinery, Facility and Process Approval[EN]
Witten - Forging Facility and Process Approval[EN]
Siegen - Foundry Facility and Process Approval[EN]
Siegen - Rolled Bars - Machinery, Facility and Process Approval[EN]

BV - Bureau Veritas

Witten - Steelmaking, rolling and forgings[EN]
Krefeld- forgings[EN]
Siegen - Steelmaking and rolling[EN]

Class NK - Nippon Kaiji Kyokai

Witten - Casting & Forging[EN]

CCS China Classification Society

Witten - Semi-finished products (ingot billets / billets)[EN]
Witten - Bars (rolled)[EN]
Witten / Krefeld - Bars (forged)[EN]
Witten / Krefeld - Semi-finished products (forged)[EN]

DNV

Witten - Steel forgings (inkl. HY-80, HY-100)[EN]
Witten - Steelmaking & rolled steel products (inkl. HY-80, HY-100) [EN]
Krefeld - Steel forgings[EN]
Siegen - Steelmaking & rolled Steel products[EN]
Hagen - Rolled steel products[EN]
Witten - OS-E302 Offshore Mooring Chain [EN]
Krefeld - OS-E302 Offshore Mooring Chain [EN]

LR - Lloyd's Register

Siegen - Steelmaking and bars [EN] 
Witten - Steelmaking, Semi-Finished Products and Bars [Interim]  [EN]  
Witten - Forgings [Interim] [EN]
Krefeld - Forgings [Interim] [EN]

KRS - Korean Register of Shipping

Witten - steelmaking, rolling, forgings[EN]
Krefeld - forgings[EN]
Siegen - steelmaking, rolling[EN]

RINA - Registro Italiano Navale

Witten, Krefeld - Steelmaking, rolling and forging[EN]