Midland Alloys Inc. is a trusted manufacturer and supplier of Stainless Steel 304/304L Buttweld Fittings for piping systems across industries. Our product range includes SS 304 buttweld elbows, tees, reducers, and caps, all known for high corrosion resistance, easy weldability, and long service life. We provide fittings of various types and customizable sizes that fulfill ASTM and ASME requirements. Whether you require SS 304L buttweld fittings or 304L stainless steel pipe fittings, we have ready stock at an affordable price. As an ISO certified company, we ensure strict quality checks and on-time delivery. Whether it’s SS 304 or 304L, our fittings are made to perform in demanding environments. Choose us for dependable fitting built to specification and delivered with care.

SS 304/304L Buttweld Fittings

What Are SS 304/304L Butt Weld Fittings?

SS 304 and 304L butt weld fittings are utilized in stainless steel piping systems that require strong, long-lasting welded joints.  These fittings are made of austenitic stainless steel, which is known for its high corrosion resistance, weldability, and strength. 304L is the low-carbon version of 304, which reduces the possibility of carbide formation during welding. Both grades, UNS S30400 and UNS S30403, remain non-magnetic when annealed and perform well in most standard settings. These 304 stainless steel pipe fittings hold up against oxidation and intergranular corrosion. Their formability and stable structure make them reliable for consistent welding, and shaping. Manufactured to ASTM A403 WP304/WP304L and ASME B16.9 standards, they fit a wide range of system requirements.

Stainless Steel 304/304L Buttweld Fittings

Advantages of Stainless 304/304l Buttweld Fittings

Stainless steel 304L and SS 304 buttweld fittings are renowned due to their continuous performance, and structural integrity. These fittings are used in a variety of industries including chemical processing and food and beverage, because of their outstanding corrosion resistance, mechanical strength, and ease of welding. The following section focuses on the key technical benefits that make 304L stainless steel pipe fittings a reliable solution for a variety of piping applications.
  • Low carbon content: The reduced carbon level in stainless steel pipe fittings 304L minimizes carbide precipitation during welding, enhancing weld joint reliability.
  • Because of their dependable structural integrity and consistent performance, stainless steel 304L and SS 304 buttweld fittings are highly valued.
  • Austenitic microstructure: Their austenitic structure ensures superior toughness and ductility, even in cryogenic temperatures.
  • Stable under heat: 304L stainless steel pipe fittings maintain mechanical strength and oxidation resistance even under elevated temperatures.
  • Non-magnetic (annealed): Stainless steel 304L buttweld fittings remain non-magnetic in their annealed condition, making them suitable for sensitive applications.
  • Oxidation resistant: Long-term durability in hot or oxidizing conditions is ensured by these fittings’ resistance to scale and oxidation.

SS 304 vs 304L Buttweld Fitting

SS 304 and 304L buttweld fittings look similar but differ in carbon content. 304L has lower carbon, which helps prevent carbide buildup during welding. That makes it a better pick for welded systems. Both offer strong corrosion resistance, but 304L holds up better over time in harsh settings. They share similar strength and toughness, but 304L is often used where welding is key. In contrast, 304 suits non-welded parts or where slightly higher strength is needed.

SS 304/304L Buttweld Fittings Specifications

This table outlines the key specifications of ASTM A403 WP304 and WP304L butt weld pipe fittings, including standards, dimensions, schedules, and types available for industrial applications.

Buttweld FIttings
Sizes in Stock

Seamless Butt Weld Fittings: 1/2" - 10" Welded Butt Weld Fittings: 1/2" - 48"

ASTM Standard
Standard

ASTM A403 / ASME SA403

Process
Manufacturing Process

Forge, Cast, Push, Press, etc.

Buttweld Fitting Form
Form

90 Deg. Elbow, 45 Degree Elbow, LR/SR Elbow, Reducers, Tee, Cross, Bends, U bend, 180 Deg Bend, End Cap, Lap-joint Stub End

Dimensions Buttweld Fittings
Dimensions

ASME/ANSI B16.9, ASME B16.28, MSS-SP-43, BS4504, BS4504, BS1560, BS10

Buttweld Fittings End
End

Plain End, Beveled End, Treaded

Schedule
Schedule

SCH10, SCH20, SCH30, STD SCH40, SCH60, XS, SCH 80, SCH 100, SCH 120, SCH 140, SCH 160, XXS available with NACE MR 01-75

Types
Type

Seamless / Welded / Fabricated

Types of Stainless Steel 304/304L Buttweld Fittings

304/304L Stainless Steel  Buttweld fittings are precision-engineered components that connect pipe sections in a variety of industrial piping systems. Known for their excellent corrosion resistance, high strength and durability, these fittings are widely used in chemical, petrochemical, food processing, and water treatment applications. They come in a variety of forms and shapes to support varying flow directions, sizes, and configurations inside complex piping layouts.

  • Elbow (90°, 45°, Long/Short Radius)
    Elbow (90°, 45°, Long/Short Radius)

    Used to change the direction of flow in a pipeline at specified angles; available in short or long radius.

  • Tee (Equal & Reducing)
    Tee (Equal & Reducing)

    Divides flow into two branches; an equal tee has all ends the same size, a reducing tee has one smaller outlet.

  • Reducer (Concentric & Eccentric)
    Reducer (Concentric & Eccentric)

    Connects pipes of different diameters; concentric type is symmetrical, eccentric has an offset centerline.

  • Stub End (Short & Long Pattern)
    Stub End (Short & Long Pattern)

    Used with lap joint flanges to allow easy dismantling; available in short and long lengths.

  • End Cap
    End Cap

    Closes the end of a pipe to stop flow and protect the system.

  • Cross (Equal & Reducing)
    Cross (Equal & Reducing)

    Connects four pipes; equal type has all ports the same size, reducing type has different sized outlets.

  • Lateral Tee
    Lateral Tee

    Branches pipe at a 45° angle for smoother flow direction changes.

  • Return Bends (180°)
    Return Bends (180°)

    Return bends are U-shaped fittings that reverse the flow direction by 180°. They are commonly seen in heat exchangers and coil systems.

  • Collar
    Collar

    A collar is a short, cylindrical ring used to reinforce pipe ends, improve sealing, or aid in the alignment of adjoining pipes.

  • Nipple
    Nipple

    Nipples are short lengths of pipe used for close-fitting connections between other fittings or components, usually threaded or beveled.

  • Barred Tee
    Barred Tee

    Barred tees are fitted with internal bars to prevent pigging tools from entering the branch line, ensuring uninterrupted pipeline cleaning or inspection.

  • Expansion Joint
    Expansion Joint

    Expansion joints absorb movement, vibration, and thermal expansion in piping systems, protecting the structure from stress and fatigue.

  • Swage Nipple
    Swage Nipple

    Swage nipples are transition fittings that connect pipes of varying sizes, often used in high-pressure applications where gradual reduction is required.

  • Reducer Insert
    Reducer Insert

    Reducer inserts are inserted within another fitting or flange to reduce bore size, giving a cost-effective and compact solution.

Contact Midland Alloys Inc. for Your Stainless Steel 304/304L Buttweld Fittings Needs
Contact us today to discuss how Stainless Steel 304/304L Buttweld Fittings can benefit your application. Whether you need guidance in selecting the right Buttweld Fittings or have specific requirements, our team of experts is here to help you find the optimal solution.

Technical Details & Delivery Condition

The table below details the chemical composition of SS 304 and 304L butt weld fittings, highlighting the percentages of components such as chromium, nickel, carbon, and others that are required for corrosion resistance and performance.

GradeCMnSiPSCrMoNiN
SS 3040.08 max2 max0.75 max0.045 max0.030 max18 – 208 – 11
SS 304L0.035 max2.0 max1.0 max0.045 max0.03 max18 – 208 – 13

This table displays the mechanical properties of SS 304 and 304L butt weld fittings, including tensile strength, yield strength, elongation, and hardness, which help in determining their structural suitability.

GradeTensile Strength (MPa) minYield Strength 0.2% Proof (MPa) minElongation (% in 50mm) minHardness
Rockwell B (HR B) maxBrinell (HB) max
3045152054092201
304L4851704092201

Here you’ll find a comparison table of equivalent grades for SS 304 and 304L across various international standards such as UNS, EN, JIS, and DIN for easy cross-reference in global projects.

STANDARDUNSWNR.AFNORENJISBS
SS 304S304001.4301Z7CN18-09X5CrNi18-10SUS 304304S31
SS 304LS304031.4306Z3CN18-10X2CrNi18-9 / X2CrNi19-11SUS 304L304S11

The table below lists the permissible alignment tolerances for ASTM A403 WP304 and
WP304L pipe fittings, covering aspects like angular, offset, and linear tolerances as per standard manufacturing
norms.

Nominal Pipe Size (NPS)Off Plane Tolerances, ±
A
Off Angle Tolerances, ±
B
Alignment of Ends, ±
C
inmminmminmm
½ to 40.0620.0310.031
5 to 80.1240.0620.031
10 to 120.1950.0920.062
14 to 160.2560.0930.062
18 to 240.38100.1240.062
26 to 300.38100.195
32 to 420.50130.195
44 to 480.75190.195

The table below shows the size options for SS 304 and 304L butt weld fittings, including nominal pipe sizes (NPS), outer diameters, wall thicknesses, and schedule classifications.

Nominal
Pipe
Size
Outside
Diameter
90° Elbows45° Elbows180° Returns
(inches)
 
Long Radius
Short Radius
Long Radius
Long Radius
 
(mm)
(inches)
Center to Face
(inches)
Center to Face
(inches)
Center to Face
(inches)
Radius
(inches)
Center to Center
(inches)
Back to face
(inches)
1/2
21.3
0.840
1 1/2
5/8
 
2
1 7/8
3/4
26.7
1.050
1 1/8
7/16
 
2 1/4
1 11/16
1
33.4
1.315
1 1/2
1
7/8
 
3
2 3/16
1 1/4
42.2
1.660
1 7/8
1 1/4
1
 
3 3/4
2 3/4
1 1/2
48.3
1.900
2 1/4
1 1/2
1 1/8
3
4 1/2
3 1/4
2
60.3
2.375
3
2
1 3/8
4
6
4 3/16
2 1/2
73.0
2.875
3 3/4
2 1/2
1 3/4
5
7 1/2
5 3/16
3
88.9
3.500
4 1/2
3
2
6
9
6 1/4
3 1/2
101.6
4.000
5 1/4
3 1/2
2 1/4
7
10 1/2
7 1/4
4
114.3
4.500
6
4
2 1/2
8
12
8 1/4
5
141.3
5.563
7 1/2
5
3 1/8
10
15
10 5/16
6
168.3
6.625
9
6
3 3/4
12
18
12 5/16
8
219.1
8.625
12
8
5
12
24
16 5/16
10
273.1
10.750
15
10
6 1/4
15
30
20 3/8
12
323.9
12.750
18
12
7 1/2
18
36
24 3/8

Stainless Steel Buttweld Fittings We Offer

Manufacturing Process of 304 Buttweld Fitting

The first step in the production of 304 stainless steel buttweld fittings is choosing premium raw materials that adhere to ASTM A403. The stainless steel is then cut to the required size using precision cutting tools. Forming procedures such as hot or cold forming are then used to shape elbows, tees, reducers or other fittings. The fittings are heat-treated after forming in order to reduce stress, and improve mechanical strength. Pickling or shot blasting are methods used for surface finishing in order to eliminate scale and guarantee a clean, corrosion-resistant surface. Each fitting then goes through strict dimensional checks, visual inspection and non-destructive testing to verify quality and compliance. Final products are marked, documented and prepared for shipment

Raw Material

Pipe

arrow
Cutting

Cutting

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Sizing

Forming

arrow
Heat Treatment

Sizing

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Pickling

Heat Treatment

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Pickling

Pickling

arrow
Beveling

Beveling

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Polishing

Polishing

arrow
Sand Blasting

Sand Blasting

arrow
Inspection

Elbow

arrow
Inspection

Inspection

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Analytic

Analytic

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Marking

Marking

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Packing & Shipping

Packing & Shipping

Industrial Applications for 304, 304L SS Buttweld Fittings

Many different industries rely on 304 and 304L stainless steel buttweld fittings because of their strength, resistance to corrosion and capacity to withstand high temperatures and pressures. Chemical processing plants use them to safely transport acids, solvents, and other harsh fluids through pipelines.  The food and beverage sector relies on them in processing lines where hygiene and ease of cleaning are critical. In pharmaceutical manufacturing, they help maintain sterile, contamination-free flow systems for critical products. The oil and gas industry uses these fittings in pipelines and refineries, where they are exposed to extreme heat and pressure every day. At water treatment plants, they support both clean water and wastewater systems, providing long service life even in harsh environments. They are used in power plants to manage steam, high-pressure fluids, and other extreme situations.  From clean rooms to heavy-duty pipes, these fittings keep systems connected, secure, and leak-free.

Why Choose Midland Alloys Inc.?

Midland Alloys Inc. is an ISO 9001 certified manufacturer known for its commitment to quality in delivering ASTM A403 WP 304L Stainless Steel Buttweld Fittings. With a strong global export network, we guarantee prompt delivery in all major industrial areas.  We offer stainless steel 304L butt weld fittings in a variety of custom lengths, finishes and coil shapes to fulfill various project demands. Our team provides 24/7 customer assistance and ensures complete 304L Butt Weld Fittings Test Certificate and material traceability for every order.

FAQs –SS 304/304L Buttweld Fittings

No, due to their corrosion resistance, 304/304L buttweld fittings require little care; however, regular examination, and cleaning in severe situations is suggested.

They are welded to pipes using butt welding techniques typically involving TIG or MIG welding for strong, leak-proof joints.

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