Stainless Steel 316 Pipe Fittings | ASTM A403 WP316 SS 316 Fittings Supplier

Solitaire Overseas supplies the full ASTM A403 WP316 and WP316L product range, including stainless steel buttweld fittings for welded piping networks and stainless steel forged fittings for high-pressure service. Fittings are available from NPS 1/2 inch to 48 inch in seamless and welded construction, across all standard schedules from SCH 10 through XXS.

The addition of 2 to 3 percent molybdenum in grade 316 gives it a higher PREN than grade 304, making it the correct material selection for service environments involving chloride ions, seawater, acidic process fluids, and aggressive cleaning cycles. For applications requiring post-weld corrosion resistance without annealing, 316L (low-carbon variant, 0.03 percent C max) is the specified choice.

Looking to buy Stainless Steel Flanges?

Check price of Stainless Steel 304, Stainless Steel 316 & Stainless Steel 904L Flanges

Weight Calculator

ASTM A403 WP316 Stainless Steel Pipe Fittings Manufacturer and Supplier in India

As an ISO-certified manufacturer of ASTM A403 WP316 stainless steel 316 fittings in India, we supply a complete range of buttweld fittings — elbows, tees, reducers, caps, and stub ends to engineering, EPC, and export customers across 60+ countries.

We manufacture in compliance with ASME B16.9 and B16.28, in both seamless and welded (ERW) forms. Our in-house ISO-certified quality control, 100% radiography testing, and support for custom sizes from NPS ½" to 24" make us a trusted source for complex engineering and export projects. Full EN 10204 3.1 and 3.2 material test certificates are available on request, along with third-party inspection by SGS, Bureau Veritas, or Lloyd's Register.

Standard stock items dispatched within 3–5 working days from our Mumbai warehouse. Custom sizes and certified material: 2–4 weeks. Export packaging and sea-freight documentation included.

For more information and pricing on 316 Stainless Steel Fittings, please contact us directly.

Stainless Steel 316 Fittings Specifications
316 Stainless Pipe Fittings Chemical Composition
Mechanical Properties of 316 Pipe Fittings
Equivalent Grades of Stainless Steel 316 Pipe Fittings
When to Specify 316L Over 316
Pressure Ratings for SS 316 Pipe Fittings
Size Chart of 316 Stainless Steel Fittings
316 Stainless Fittings Weight Chart (Sch 10S / 40S / 80S)
ASTM A403 WP316 Fittings HS Code
SS 316 Pipe Fittings Dimensions
SS 316 Pipe Fittings Dimensions — Elbows (Centre-to-End) per ASME B16.9
Types of Stainless Steel 316 Pipe Fittings
Fabrication Notes for SS 316 Fittings
Applications of Stainless Steel 316 Fittings
Frequently Asked Questions
Related Products

Stainless Steel 316 Fittings Specifications

We maintain a comprehensive stock of Stainless Steel 316 fittings. Below are the key specifications for our inventory.

Category	Specification Details
Specifications	ASTM A403 / ASME SA403
Material	WP316 / WP316L
Dimension Standards	ASME/ANSI B16.9 \| ASME B16.28 \| MSS-SP-43 \| BS1560 \| BS4504 \| BS10
Schedules Available	SCH 10, SCH 20, SCH 30, STD, SCH 40, SCH 60, XS, SCH 80, SCH 100, SCH 120, SCH 140, SCH 160, XXS — NACE MR0175 available
Types	Seamless \| Welded (ERW) \| Fabricated
Bending Radius	R = 1D, 2D, 3D, 5D, 6D, 8D, 10D
Size Range — Seamless	½" NPS to 10" NPS
Size Range — Welded	½" NPS to 48" NPS (DN 15 to DN 1200)
Surface Finish	2B (mill standard) \| No. 4 brushed \| BA (bright annealed) \| Electro-polished Ra ≤ 0.8 µm (food/pharma) \| Pickled & passivated
Quality Approvals	ISO 9001:2015 \| EN 10204 3.1/3.2 MTC \| NACE MR0175/ISO 15156 compliance available \| Third-party inspection: SGS, BV, TUV on request
Testing	100% Radiography \| Hydrostatic \| PMI (Positive Material Identification) \| Visual & dimensional per ASME B16.9

316 Stainless Pipe Fittings Chemical Composition

The critical differentiator is molybdenum (Mo) at 2.00–3.00% — absent in grade 304. This element raises the Pitting Resistance Equivalent Number (PREN) from approximately 18 (grade 304) to approximately 25 (grade 316), providing a measurable improvement in resistance to chloride-induced pitting corrosion.

C	Si	Mn	P	S	Cr	Ni	Mo	Fe
0.08 max	1.0 max	2.0 max	0.045 max	0.030 max	16.00–18.00	11.00–14.00	2.00–3.00	67.845 min

Mechanical Properties of 316 Pipe Fittings

Melting Point	Density	Yield Strength (0.2% offset)	Elongation	Tensile Strength
1400°C / 2552°F	8.0 g/cm³	30,000 PSI / 205 MPa	35%	75,000 PSI / 515 MPa

Equivalent Grades of Stainless Steel 316 Pipe Fittings

AISI/ASTM	UNS	Werkstoff Nr.	JIS	EN	BS	AFNOR
316 (A276, A403, A479)	S31600	1.4401 / 1.4436	SUS 316	X5CrNiMo17-12-2 / X3CrNiMo17-13-3	316S31 / 316S33	Z7CND17-11-02

When to Specify 316L Over 316

For all welded installations, specify 316L (WP316L per ASTM A403). The low-carbon formulation (max 0.03% C vs 0.08% for standard 316) eliminates the risk of sensitisation — chromium carbide precipitation at weld heat-affected zones that can create intergranular corrosion paths in aggressive environments.

Standard 316 is acceptable for non-welded, mechanical connections. For all piping that will be field-welded or shop-welded without post-weld annealing, WP316L is the correct specification. Both grades carry the same molybdenum content and corrosion resistance — the difference is only in carbon content and therefore weld performance.

Property	316 (WP316)	316L (WP316L)
Max Carbon (C)	0.08%	0.03%
Molybdenum (Mo)	2.00–3.00%	2.00–3.00%
Chloride resistance	Excellent	Excellent
Weld sensitisation risk	Moderate — anneal recommended	Very low — no post-weld anneal required
Food/pharma use	Suitable	Preferred (low C prevents CIP attack)
ASTM fitting spec	A403 WP316	A403 WP316L

Pressure Ratings for SS 316 Pipe Fittings

Pressure ratings are determined by fitting type, connection class, and wall schedule. The following are indicative cold working pressure ratings at ambient temperature:

Connection Type	Standard	Class/Schedule	Approx. Max Pressure
Threaded / Socket Weld	ASME B16.11	Class 3000	~3,000 PSI (207 bar)
Threaded / Socket Weld	ASME B16.11	Class 6000	~6,000 PSI (414 bar)
Threaded / Socket Weld	ASME B16.11	Class 9000	~9,000 PSI (621 bar)
Butt Weld	ASME B16.9	Schedule 40 @ 1" NPS	~740 PSI (51 bar)
Butt Weld	ASME B16.9	Schedule 80 @ 1" NPS	~1,130 PSI (78 bar)
Butt Weld	ASME B16.9	Schedule 160 @ 1" NPS	~2,050 PSI (141 bar)
Flanged	ASME B16.5	Class 150	~275 PSI (19 bar) ambient
Flanged	ASME B16.5	Class 600	~1,480 PSI (102 bar) ambient

Note: All pressure ratings decrease with increasing temperature. Derate per ASME B31.3 for your service temperature. Class ratings are for cold working pressure (CWP) / water, oil, gas (WOG) service.

Size Chart of 316 Stainless Steel Fittings

Cap dimensions per ASME B16.9 (mm). All rows sorted by NPS ascending.

NPS (inches)	OD (mm)	Cap Length (mm)
1/2	21.3	25
3/4	26.7	25
1	33.4	38
1.1/4	42.2	38
1.1/2	48.3	38
2	60.3	38
2.1/2	73.0	38
3	88.9	51
3.1/2	101.6	64
4	114.3	64
5	141.3	76
6	168.3	89
8	219.1	102
10	273.0	127
12	323.8	152
14	355.6	165
16	406.4	178
18	457.0	203
20	508.0	229
22	559.0	254
24	610.0	267
26	660.0	267
28	711.0	267
30	762.0	267
32	813.0	267
34	864.0	237
36	914.0	267
38	965.0	305
40	1016.0	305

All dimensions per ASME B16.9 / MSS SP-43. Other schedules and fitting types on request.

316 Stainless Fittings Weight Chart — Sch 10S / 40S / 80S (kg)

90° Long Radius Elbow — Weight (kg)

NPS (inches)	DN (mm)	Sch 10S	Sch 40S	Sch 80S
1/2	15	0.04	0.05	0.07
3/4	20	0.07	0.08	0.11
1	25	0.14	0.15	0.21
1.1/2	40	0.29	0.40	0.56
2	50	0.59	0.70	0.99
3	80	1.50	1.77	2.50
4	100	2.81	3.46	5.00
6	150	8.16	8.07	12.00
8	200	16.56	15.65	24.00
10	250	25.86	26.46	40.00
12	300	39.69	39.46	60.00

Source: ASME B16.9. All weights are approximate and for planning purposes only — confirm with mill certifications.

ASTM A403 WP316 Fittings HS Code

For streamlined international logistics and customs clearance, reference the following Harmonized System codes for ASTM A403 WP316 stainless steel fittings:

Fitting Type	HS Code	Description
Butt-weld fittings (elbows, tees, reducers)	7307.23.00	Tube or pipe fittings of stainless steel — butt welding fittings
Threaded, socket-weld, other fittings	7307.99.00	Tube or pipe fittings of stainless steel — other

Verify against current Indian Customs Tariff and destination country tariff schedule at time of shipping. Chapter 73.07 covers all iron/steel pipe fittings.

SS 316 Pipe Fittings Dimensions — Caps, Tees, Crosses & Stub Ends

Dimensions per ASME B16.9. OD in both metric (mm) and imperial (inches).

NPS (in)	OD (mm)	OD (in)	Cap Length (in)	Tee C-E (in)	Cross C-E (in)	Stub End Lap Ø (in)	Stub Long (in)	Stub Short (in)
1/2	21.3	0.840	1	1	–	1 3/8	3	2
3/4	26.7	1.050	1	1 1/8	–	1 11/16	3	2
1	33.4	1.315	1 1/2	1 1/2	1 1/2	2	4	2
1 1/4	42.2	1.660	1 1/2	1 7/8	1 7/8	2 1/2	4	2
1 1/2	48.3	1.900	1 1/2	2 1/4	2 1/4	2 7/8	4	2
2	60.3	2.375	1 1/2	2 1/2	2 1/2	3 5/8	6	2 1/2
2 1/2	73.0	2.875	1 1/2	3	3	4 1/8	6	2 1/2
3	88.9	3.500	2	3 3/8	3 3/8	5	6	2 1/2
4	114.3	4.500	2 1/2	4 1/8	4 1/8	6 3/16	6	3
6	168.3	6.625	3 1/2	5 5/8	5 5/8	8 1/2	8	3 1/2
8	219.1	8.625	4	7	7	10 5/8	8	4
10	273.1	10.750	5	8 1/2	8 1/2	12 3/4	10	5
12	323.9	12.750	6	10	10	15	10	6

SS 316 Pipe Fittings Dimensions — Elbows (Centre-to-End) per ASME B16.9

Dimensions per ASME B16.9. OD in both metric (mm) and imperial (inches).

NPS (in)	OD (mm)	90° LR Elbow C-E (in)	90° SR Elbow C-E (in)	45° LR Elbow C-E (in)	180° LR Return C-C (in)
1/2	21.3	1 1/2	1	15/16	3
3/4	26.7	1 1/2	1	1 1/8	3
1	33.4	1 1/2	1	1 1/2	3
1 1/2	48.3	2 1/4	1 1/2	1 7/8	4 1/2
2	60.3	3	2	2 1/2	6
3	88.9	4 1/2	3	3 3/4	9
4	114.3	6	4	5	12
6	168.3	9	6	7 1/2	18
8	219.1	12	8	10	24
10	273.1	15	10	12 1/2	30
12	323.9	18	12	15	36

Types of Stainless Steel 316 Pipe Fittings

Our inventory covers a full spectrum of 316 stainless steel pipe fittings and 316 stainless steel tube fittings to accommodate any piping configuration.

SUS 316 Cross

INOX 316 Nipple

SS 316 Short Radius Pipe Elbows

WNR 1.4401 Long Radius Return Bends

UNS S31600 Reducing Elbow

AISI 316 Stub Ends

316 Stainless Steel Coupling

316 Stainless Steel Unequal Tee

ASTM A403 WP316 Pipe Caps

Stainless Steel 316 Short Radius Return Bends

ASTM A403 Gr Wp316 Concentric Reducer

ASTM A403 Grade WP316 Collar Pipe Fittings

Fabrication Notes for SS 316 Fittings

Grade 316 is weldable by all standard fusion methods, with or without filler metals. For welded service, specify WP316L (low-carbon) to eliminate sensitisation risk at the weld heat-affected zone — post-weld annealing is not required for 316L.

If standard 316 fittings have been welded, restore full corrosion resistance by solution annealing at 1,050–1,150°C (1,922–2,102°F) followed by rapid water quench. Avoid service in the sensitisation temperature range of 425–860°C (797–1,580°F) without subsequent annealing.

Machining note: 316 work-hardens rapidly. Use heavy positive feeds at low speeds with chip breakers, generous cutting fluid, and sharp tooling to avoid galling.

Applications of Stainless Steel 316 Fittings

The molybdenum content in grade 316 makes these fittings the standard specification wherever chlorides, acids, or aggressive chemicals are present. Below are the primary industries and the specific reason 316 is required over grade 304:

Specialty Chemicals: Process streams containing hydrochloric, phosphoric, and sulphuric acids at concentrations and temperatures that cause rapid pitting in grade 304. Grade 316 provides the additional corrosion barrier required for reliable service life.
Oil & Gas / Offshore: Seawater injection lines, chemical dosing systems, and topside piping on offshore platforms are exposed to chloride-rich environments. Grade 316 stainless pipe fittings are mandated by NORSOK M-630 and similar offshore standards.
Marine & Seawater Equipment: 316 stainless fittings resist seawater and brine solutions at ambient temperature where 304 would suffer pitting corrosion within months. Standard specification for desalination, shipbuilding, and coastal infrastructure.
Pharmaceuticals: 316L (low-carbon variant) is required for direct-product-contact piping in pharmaceutical manufacturing per FDA and GMP guidelines. The electro-polished surface finish (Ra ≤ 0.8 µm) prevents microbial retention.
Food & Beverage: 316L sanitary fittings (tri-clamp, SMS, DIN 11851) are specified for dairy, beverage, and food processing lines. Resistance to CIP (clean-in-place) chemicals such as caustic soda and nitric acid makes 316L the hygienic grade of choice.
Power Generation: Condenser tubing systems, cooling water circuits, and flue gas desulphurisation (FGD) units operate in high-chloride environments where 304 would suffer crevice corrosion. 316 extends maintenance cycles significantly.
Pulp & Paper: Chlorine-based bleaching agents and high-temperature wash liquors attack standard stainless. Grade 316 fittings in pulp digesters and bleach plant piping outlast 304 by a factor of 3–5x in service life.
Heat Exchangers: 316 stainless fittings are used on the waterside of heat exchangers handling cooling tower water, seawater, or brackish water — environments where chloride concentration is high enough to initiate pitting on grade 304 surfaces.
Gas Processing: Natural gas dehydration units and amine treating systems use 316 stainless fittings to handle wet gas, condensate, and glycol/amine solutions that contain dissolved chlorides and H₂S.

Frequently Asked Questions About Stainless Steel 316 Fittings

What is the difference between 304 and 316 stainless steel fittings?

The primary difference is molybdenum present at 2–3% in grade 316 and absent in 304. Molybdenum dramatically improves resistance to pitting and crevice corrosion from chloride ions, making 316 stainless steel pipe fittings the correct specification for marine, chemical processing, offshore, and coastal environments where grade 304 would corrode prematurely.

What pressure rating do SS 316 pipe fittings have?

Pressure ratings depend on fitting type and class. Socket-weld and threaded fittings per ASME B16.11 are rated Class 3000 (~3,000 PSI), Class 6000 (~6,000 PSI), or Class 9000. Butt-weld fittings per ASME B16.9 are rated by wall schedule (Schedule 40, 80, 160) — see the Pressure Ratings table above for specifics. All ratings decrease with increasing temperature; derate per ASME B31.3 for your service conditions.

How long does 316 stainless steel last?

With minimal maintenance, grade 316 stainless steel fittings are engineered for 20–50 years or more of service life, depending on environment and media. The molybdenum content provides extended service in chloride-bearing applications such as marine, chemical, and offshore environments where grade 304 would require replacement in a fraction of that time.

What are stainless steel fittings used for?

Stainless steel 316 pipe fittings are used to connect, control, change the direction of, and terminate piping systems in industries including oil & gas, chemical processing, pharmaceuticals, food & beverage, marine, power generation, and water treatment — wherever corrosion resistance, hygiene, and pressure-bearing reliability are required.

What types of end connections are available for SS 316 fittings?

SS 316 fittings are available in five end connection types: Butt Weld (ASME B16.9), Socket Weld, Threaded/Screwed (ASME B16.11), Flanged (ASME B16.5), and Compression/Instrumentation. Selection depends on pressure class, pipe schedule, and whether the joint needs to be dismantleable for maintenance.

What is the maximum service temperature for Grade 316 stainless steel fittings?

Grade 316 stainless steel fittings maintain structural integrity at continuous operating temperatures up to 870°C (1,598°F) in oxidising atmospheres, and up to 925°C (1,697°F) in intermittent service. For aqueous service with chlorides, the critical pitting temperature (CPT) is the more relevant limit — typically above 15°C for seawater with grade 316.

Which manufacturing processes are used to produce 316 stainless steel weld fittings?

316 stainless steel weld fittings are typically manufactured using processes such as seamless pipe forming, hot or cold forging, fabrication from stainless steel plates, and precision welding techniques. After forming, the fittings undergo CNC machining, heat treatment (solution annealing), and surface finishing processes like pickling and passivation to ensure high strength, dimensional accuracy, and superior corrosion resistance for industrial applications.

Get the latest pricing for Stainless Steel 316 Fittings! Email vishal@solitaire-overseas.com now for an immediate quote and our updated 2025 price guide.