Glossary
The short forms used in metal enquiries, mill certificates and purchase specifications — explained in one place.
Materials & standards
| Abbreviation | Meaning |
|---|---|
| SS | Stainless steel |
| MS | Mild steel |
| CS | Carbon steel |
| DSS | Duplex stainless steel |
| SDSS | Super duplex stainless steel |
| PH | Precipitation hardening |
| UNS | Unified Numbering System (alloy designation) |
| W.Nr. | Werkstoffnummer — German / EN material number |
| EN | European Norm (standard) |
| ASTM | ASTM International (American Society for Testing and Materials) |
| ASME | American Society of Mechanical Engineers |
| DIN | Deutsches Institut für Normung (German standard) |
| JIS | Japanese Industrial Standard |
| BS | British Standard |
| IS | Indian Standard (BIS) |
Pipes & tubes
| Abbreviation | Meaning |
|---|---|
| NB | Nominal bore (pipe size) |
| OD | Outside diameter |
| ID | Inside diameter |
| WT | Wall thickness |
| SCH | Schedule (wall-thickness series) |
| SRL | Single random length (approx. 5–7 m) |
| DRL | Double random length (approx. 11–13 m) |
| ERW | Electric resistance welded |
| EFW | Electric fusion welded |
| SAW | Submerged arc welded |
Flanges & fittings
| Abbreviation | Meaning |
|---|---|
| SORF | Slip-on raised face flange |
| WNRF | Weld-neck raised face flange |
| BLRF | Blind raised face flange |
| SWRF | Socket-weld raised face flange |
| RTJ | Ring-type joint |
| LR | Long radius (elbow) |
| SR | Short radius (elbow) |
| NPT | National Pipe Thread (tapered) |
| BSP | British Standard Pipe thread |
| BSPT | British Standard Pipe Taper thread |
Finishes
| Abbreviation | Meaning |
|---|---|
| 2B | Cold rolled, annealed, pickled and skin-passed (smooth matt) |
| BA | Bright annealed (reflective) |
| No.4 | Brushed / satin finish |
| No.8 | Mirror-polished finish |
| HL | Hairline finish |
Documents
| Abbreviation | Meaning |
|---|---|
| MTC | Mill Test Certificate |
| TPI | Third-party inspection |
| RFQ | Request for quotation |