Lateral — MSS SP-43 / manufacturer standard
Lateral — a fitting with a 45° branch. Laterals bring in a branch at 45°, reducing turbulence and pressure drop compared to a tee. Common in drainage, slurry and process lines.
- MSS SP-43 / manufacturer standard
- 22 grades
- EN 10204 3.1 / 3.2
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is a lateral?
A lateral is a fitting with a 45° branch. Laterals bring in a branch at 45°, reducing turbulence and pressure drop compared to a tee. Common in drainage, slurry and process lines.
Standards for laterals
Lateral: What to Know Before Ordering
- 45° branch
- Equal and reducing
- Often fabricated
Lateral Materials & Grades
| Grade | Material standard | Best for |
|---|---|---|
| Inconel 825 lateral | ASTM B366 WPNICMC | Sulphuric and phosphoric acid service, chloride stress-corrosion cracking and sour gas |
| SS 904L lateral | ASTM A403 WP904L | Dilute sulphuric acid, phosphoric acid and chloride-bearing cooling water |
| SS 304 lateral | ASTM A403 WP304 | General corrosion resistance, food, water and architectural work |
| SS 304L lateral | ASTM A403 WP304L | Welded tanks, piping and vessels in general corrosive service |
| SS 310 / 310S lateral | ASTM A403 WP310S | Furnaces, burners and heat treatment at high temperature |
| SS 316 / 316L lateral | ASTM A403 WP316L | Chloride-bearing process fluids, marine air and pharmaceutical service |
| SS 321 lateral | ASTM A403 WP321 | High-temperature service between 425 and 815 °C |
| SS 347 lateral | ASTM A403 WP347 | Welded high-temperature piping in refineries and power plants |
| Duplex 2205 lateral | ASTM A815 WPS31803 / WPS32205 | Strength with chloride resistance at a stainless-steel budget |
| Super Duplex 2507 lateral | ASTM A815 WPS32750 | Seawater and high-chloride service where strength also matters |
| Inconel 600 lateral | ASTM B366 WPNCI | High-temperature oxidation, caustic and nuclear service |
| Inconel 625 lateral | ASTM B366 WPNCMC | Seawater, high strength and high temperature in one alloy |
| Inconel 718 lateral | a specification not yet established | Very high strength at temperatures up to about 650 °C |
| Incoloy 800 / 800H / 800HT lateral | ASTM B366 WPNIC | Furnaces, petrochemical heaters and high-temperature piping |
| Hastelloy C276 lateral | ASTM B366 WPHC276 | The most aggressive mixed acids, wet chlorine and hypochlorite |
| Hastelloy C22 lateral | ASTM B366 WPHC22 | Mixed oxidising and reducing acids, and weld overlays |
| Monel 400 lateral | ASTM B366 WPNC | Seawater, hydrofluoric acid and marine service |
| Super Duplex S32760 lateral | ASTM A815 WPS32760 | Seawater firewater, injection and offshore piping |
| ASTM A106 Gr B lateral | ASTM A234 WPB | High-temperature process and steam piping in refineries and power plants |
| ASTM A333 Gr 6 lateral | ASTM A420 WPL6 | Cold-climate and refrigerated piping down to −45 °C |
| ASTM A335 P11 lateral | ASTM A234 WP11 | Steam and hot-oil piping up to about 550 °C |
| ASTM A335 P22 lateral | ASTM A234 WP22 | High-pressure steam and hydrogen service up to about 580 °C |
Other pipe fittings
Lateral — questions buyers ask
What is a lateral?
A lateral is a fitting with a 45° branch. Laterals bring in a branch at 45°, reducing turbulence and pressure drop compared to a tee. Common in drainage, slurry and process lines.
When is a lateral better than a tee?
Where lower turbulence matters — slurries, solids and gravity drainage.
Which grades are laterals available in?
Inconel 825, SS 904L, SS 304, SS 304L, SS 310 / 310S, SS 316 / 316L, SS 321, SS 347, Duplex 2205, Super Duplex 2507, Inconel 600, Inconel 625, Inconel 718, Incoloy 800 / 800H / 800HT, Hastelloy C276, Hastelloy C22, Monel 400, Super Duplex S32760, ASTM A106 Gr B, ASTM A333 Gr 6, ASTM A335 P11, ASTM A335 P22.
Which standard covers lateral dimensions?
MSS SP-43 / manufacturer standard. The material standard depends on the grade.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026