Butt weld fittings stop being practical below about NPS 2: the pipe wall gets thin, the bevels get fiddly, and the welds distort. Forged fittings take over. The pipe either enters a machined socket and is fillet welded (socket weld), or screws into a forged thread (threaded). Both systems carry pressure classes instead of schedules — the class, not a schedule, is what an order states; the class for a specific product is confirmed at enquiry.
The supplier's official classification names the full type range: forged elbows, tees and crosses, couplings, caps, unions, plugs, branch outlets, reducer inserts, swage nipples, hex and flush bushings, hex and barrel nipples, and bosses. Executions are confirmed per product at enquiry; the catalogue example on this page is the 3 inch, Class 3000, NPT plug in A105.
| Item | Range / Options |
|---|---|
| Standards | Confirmed per product at enquiry — catalogue example: 3 inch Class 3000 NPT plug in A105 |
| Types | Catalogue executions: a 3/4 inch Class 3000 socket weld elbow and a 3 inch Class 3000 NPT plug, both A105. The full type range of the supplier's official classification is named in the introduction above as classification knowledge; an execution of any other type is confirmed per product at enquiry |
| Size range | Confirmed per product at enquiry |
| Pressure classes | Catalogue execution: Class 3000 (3 inch NPT plug, A105); other classes confirmed per product at enquiry |
| Ends | Socket weld (SW) and threaded NPT ends in the catalogue executions; other end combinations confirmed per product at enquiry |
| Materials | Carbon steel ASTM A105 in the catalogue executions referenced on this site; further grades confirmed per product at enquiry |
Two Joining Systems, One Forging Logic
The two systems share the forging: a solid machined body with wall thickness far beyond the connecting pipe, which is what lets a small fitting carry Class 6000 or 9000 ratings. They differ at the joint. Socket weld fittings give a welded, leak-tight joint with a smooth bore — the standard for steam, condensate and instrument lines. Threaded fittings assemble with a wrench, can be dismantled, and suit utility and galvanised systems where welding is out. Our butt weld vs socket weld guide explains where each welded system belongs relative to butt welding.
Branch Outlets and Swages
Two forged specialties deserve naming. Branch outlet fittings branch a small line off a large header through a reinforced, contoured outlet — a far stronger construction than a welded-on pipe stub. Swage nipples step small-bore lines between sizes, concentric or eccentric. Both appear in the supplier's official classification of forged fitting types; neither is one of the catalogue executions referenced on this site, so an outlet or swage requirement is assessed for the specific product before order.
How Forged Fittings Are Ordered
Type, NPS, class, end type and grade define a forged fitting completely: for example elbow 90°, NPS 3/4, Class 3000, socket weld, A105 — a catalogue execution from our own range. Add the thread form for threaded items (NPT standard) and any outlet run size for branch fittings.
Frequently Asked Questions
What do the class numbers on forged fittings mean?
They are pressure classes from ASME B16.11. The standard's rating basis correlates the threaded classes with pipe walls — Class 2000 with Schedule 80 / XS, Class 3000 with Schedule 160, Class 6000 with XXS — and the socket weld classes run one step higher: Class 3000 with Schedule 80 / XS, Class 6000 with Schedule 160, Class 9000 with XXS. That correlation is the basis the ratings are calculated from, not a rule that only those walls may be used. The class, not a schedule, is what you state on the order.
Socket weld or threaded — which should I choose?
Socket weld for permanent, leak-critical or vibrating lines; threaded where the joint must be dismantlable, the line is galvanised, or hot work is restricted. Many plants use both: socket weld in process areas, threaded in utilities.
Do you supply forged fittings in stainless steel?
No stainless forged fitting execution is among the catalogue executions referenced on this site — name the grade on the enquiry and it will be assessed for the specific product before order.
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Send Your Specification
Tell us the size, schedule or pressure class, material grade and quantity for the forged fittings you need. MOQ and lead time are confirmed in the quotation for your exact specification.