MS fittings are a separate Metalex range. In pressure-piping procurement, a carbon-steel material grade such as ASTM A234 WPB (wrought butt-weld) or ASTM A105 (forged) may be specified; "mild steel" alone is not a substitute for the material standard, mechanical requirements or service design.
Butt-weld fitting range
ASME B16.9 covers many factory-made wrought butt-weld dimensions. MSS SP-75 specifically concerns high-strength carbon/low-alloy transmission fittings, only if that project calls for it.
| Product / attribute | Common choices to specify | Buyer check |
|---|---|---|
| Elbows: 45°, 90°, 180° returns | Long-radius and short-radius where the dimensional standard covers the form. | NPS, angle, LR/SR, schedule, bevel; ASME B16.9. |
| Tees and crosses | Equal and reducing branches; crosses subject to the applicable drawing and standard. | Run and outlet NPS, wall/schedule and branch orientation. |
| Reducers | Concentric or eccentric; choose eccentric orientation for line drainage/clearance. | Large/small-end NPS, wall at both ends and end preparation. |
| Caps and stub ends | End closures, lap-joint stub ends (short/long pattern as specified). | NPS, wall, stub-end type/length, matching flange face. |
| Bends and return bends | Long-radius pipeline bends; 180° returns under applicable dimensional rules. | Bend angle, center-line radius, tangent length, ovality and drawing. |
| Laterals and custom branches | Fabricated/wrought branch geometry where the project calls for it. | Branch angle, reinforcement/design code, drawing and inspection. |
Forged and threaded range
ASME B16.11 covers many forged socket-weld and threaded fittings. MSS practices add component-specific scopes; check the current edition and material applicability.
| Product / attribute | Common choices to specify | Buyer check |
|---|---|---|
| Socket-weld elbows, tees and crosses | 45°/90° elbows, equal/reducing tees, crosses. | Run/outlet NPS, class 3000/6000/9000 only when specified and applicable; ASME B16.11. |
| Threaded elbows, tees and crosses | 45°/90° and street elbows, equal/reducing tees and crosses. | NPS, thread form (NPT/BSP as required), class and ASME B16.11 applicability. |
| Couplings, half couplings and caps | Full/reducing couplings; half couplings and socket/threaded caps. | NPS, bore, end type, pressure class and installation clearance. |
| Unions | Socket-weld or threaded detachable connection. | NPS, pressure class 3000/6000 if applicable, seat/face; MSS SP-83. |
| Nipples, swage nipples and plugs | Hex/barrel nipples, concentric/eccentric swage nipples, bull/hex/square plugs. | End type, overall length, end sizes, thread and material; MSS SP-95 is scoped to carbon/alloy steel, not a blanket SS standard. |
| Bushings and reducer inserts | Hex/flush bushings and socket-weld reducing inserts. | Male/female end sizes, thread or socket, class; MSS SP-79 for reducer inserts. |
| Branch outlets | Weldolet (butt weld), Sockolet (socket weld), Threadolet (threaded), and other outlet configurations on drawing. | Header and branch NPS, run-wall, branch end, reinforcement and MSS SP-97 applicability. |
Size, class and material
Size and pressure class are order-specific, not a single fixed catalogue limit.
| Product / attribute | Common choices to specify | Buyer check |
|---|---|---|
| Butt-weld ends | NPS, wall thickness/schedule, bevel, radius and branch sizes. | Check ASME B16.9 vs drawing and pressure design. |
| Socket/threaded ends | NPS, thread form, class and material grade. | Confirm B16.11 and MSS practice for the item. |
| Documentation | Material certificate, heat traceability and inspection as required. | Agree scope before purchase; stock and certificate not assumed. |
What to include in your enquiry
Send the grade and material standard, product form, thickness or NPS, complete dimensions, schedule/class where relevant, finish/coating, quantity, intended application, inspection/certificate needs, destination and delivery timing. Confirm current stock and the quoted material certificate before ordering.
Technical references
Catalogue reference: Carbon-steel fittings
The catalogue names carbon-steel butt-weld grades WPB and WPHY42/46/52/60/65/70; butt-weld fitting sizes are 1/2–24 in seamless and 4–60 in welded, schedules 5–XXS. For forged fittings, carbon steel SA105 and low-temperature A350 LF2 are listed, with 1/2–4 in NB and classes 2000–9000 lb subject to form/standard.
Distinguish butt-weld ASME B16.9 fittings from forged/socket/threaded ASME B16.11 fittings on an enquiry.
Metalex catalogue (2022) describes a product range, not real-time stock or a test certificate. Confirm grade, dimensions and documentation for your enquiry.
Discuss a specification
We can check availability, documentation and size against your purchase requirement.
Contact Metalex