Stub End Manufacturer, Supplier & Exporter
A stub end, or lap joint end, is a short length of pipe with a flared lip at one end and a bevel at the other. It is butt-welded to the pipe and used with a loose lap joint flange to make a bolted joint. Raaj Fittings manufactures and exports stub ends to ASME B16.9 (long pattern) and MSS SP-43 (short pattern) in stainless steel, duplex, nickel alloys and carbon steel.
In a lap joint, only the stub end is in contact with the process fluid; the backing flange sits behind the lip and never gets wet. That means an expensive corrosion-resistant stub end can be paired with a low-cost carbon steel flange — a major saving on stainless steel, duplex and nickel alloy piping — and the flange can turn freely for easy bolt-hole alignment.
Every stub end is supplied with EN 10204 3.1 mill test certificates, with 3.2 certification on request.
We export stub ends to EPC contractors, refineries and stockists across the Middle East and GCC, Europe and the Americas — to ASME B16.9 for US and Gulf projects, or EN 10253 / DIN dimensions for European specifications, with PED-compliant supply on request.
Stub End Specifications
½" NPS to 24" NPS and larger to order
Long pattern to ASME B16.9; short pattern to MSS SP-43
Type A (lap face to suit a lap joint flange), Type B (for use with a standard slip on flange), Type C (lap formed or fabricated from pipe)
SCH 5S, 10S, 40S, 80S, 10 to 160, STD, XS
ASME B16.9, MSS SP-43, EN 1092-1 Type 32 / 33 collars on request
Seamless and welded
EN 10204 3.1 mill test certificate as standard; EN 10204 3.2 on request
Materials & Grades
We supply stub ends in the following materials and grades. All grades are supplied with EN 10204 3.1 / 3.2 Mill Test Certificates.
Stainless Steel Stub Ends
Stainless steel buttweld fittings deliver excellent corrosion resistance and are essential in chemical, pharmaceutical, food processing, and marine environments. All grades supplied to ASTM A403 specification.
(ASTM A403 WP304 / WP304L) General corrosion resistance; food, dairy, and chemical service
(ASTM A403 WP316 / WP316L) Enhanced chloride and acid resistance; pharmaceutical, marine, and chemical processing
(ASTM A403 WP316H) Elevated-temperature creep strength for high-temperature process service
(ASTM A403 WP317 / WP317L) Higher molybdenum content; superior corrosion resistance in concentrated acid service
(ASTM A403 WP321) Titanium-stabilised; resists sensitisation at sustained elevated temperatures
(ASTM A403 WP347) Columbium-stabilised; ideal for heat exchangers and high-temperature piping
High-alloy austenitic; superior resistance to hot concentrated sulfuric and phosphoric acids
Duplex & Super Duplex Stainless Steel Stub Ends
Duplex and super duplex grades offer approximately twice the yield strength of standard austenitic stainless steel, combined with excellent resistance to stress corrosion cracking and pitting — ideal for offshore, subsea, and chemical processing environments.
(UNS S31803 / S32205) Offshore topsides, chemical plant, desalination, and seawater piping
(UNS S32750) Seawater systems, subsea equipment, FPSOs, and high-chloride offshore environments
(UNS S32760) High-temperature, high-chloride offshore and subsea service applications
Nickel Alloy Stub Ends
For the most aggressive corrosive environments — concentrated acids, caustic solutions, sour gas service, and extreme temperatures — we offer buttweld fittings in a full range of nickel alloys.
(UNS N06600) High-temperature oxidation and carburisation resistance
(UNS N06625) Outstanding broad-spectrum corrosion resistance; offshore, chemical, and subsea service
(UNS N08825) Resistance to phosphoric and sulfuric acids; FGD systems and chemical plant
(UNS N10276) Universal corrosion resistance across the widest range of aggressive process media
(UNS N06022) Superior resistance to oxidising and reducing acids and pitting attack
(UNS N04400) Suitable for seawater, hydrofluoric acid, and marine and alkali service
(UNS N08020) Engineered for sulfuric acid and aggressive chemical process service
Exceptional corrosion resistance in seawater and oxidising media at low density
(C70600 / C71500) Preferred for marine seawater piping and naval condenser systems
Carbon Steel Stub Ends
Carbon steel is the most widely specified material for general-purpose, hydrocarbon, and elevated-temperature service. The primary grade is ASTM A234 WPB for standard service. For high-yield pipeline fittings, we supply ASTM A860 WPHY grades to MSS SP-75.
Standard carbon steel; primary grade for general-purpose process piping buttweld fittings
Impact-tested carbon steel for low-temperature service down to -46°C (-50°F); LNG and cryogenic piping
High-yield pipeline fittings to MSS SP-75; used in high-pressure oil, gas, and liquid transmission pipelines
How a Stub End Joint Works
The lap joint flange is slid onto the pipe first, then the stub end is butt-welded to the pipe. When the joint is bolted up, the flange pulls the lip of the stub end against the gasket and the opposite stub end. The gasket seals on the lap faces, so the flange material does not need to resist the process fluid.
- Material savings — only the stub end is in the corrosive alloy; the flange can be carbon steel.
- Easy alignment — the loose flange rotates to line up bolt holes.
- Frequent dismantling — well suited to lines opened regularly for cleaning or inspection.
Long Pattern vs Short Pattern
Long-pattern stub ends (ASME B16.9) have a longer barrel, giving room to weld away from the lap and suiting process piping with ASME B16.5 lap joint flanges. Short-pattern stub ends (MSS SP-43) are shorter and lighter, and are mainly used on light-wall stainless steel piping (SCH 5S and 10S).
Type A, B and C
Type A stub ends have a machined lap face and a radiused outer corner that matches the bore of a standard lap joint flange. Type B stub ends are made for use with a standard slip on flange as the backing flange. Type C stub ends have the lap formed from or fabricated onto pipe and are used where the other types are not available. Choose the type that matches your backing flange.
Applications & Industries
- Stainless steel, duplex and nickel alloy process piping with carbon steel backing flanges
- Chemical, pharmaceutical and food plants where lines are opened for cleaning
- Water treatment and desalination plants
- Pulp and paper and fertiliser plants
- Light-wall stainless steel utility piping (short pattern)
Explore the full range of buttweld fittings and matching flanges.
Testing, Inspection, Marking & Packing
Stub ends are made under our quality assurance process:
- Incoming material verification with PMI testing
- Chemical and mechanical testing to the applicable ASTM specification
- Heat treatment as required, with pickling and passivation for stainless steels
- Dimensional inspection of lap diameter, lap thickness, corner radius, length, wall thickness and bevel
- Gasket-face finish check on the lap
- Marking with grade, size, schedule, pattern and heat number
Supplied with EN 10204 3.1 mill test certificates; EN 10204 3.2 certificates and third-party inspection are available on request.
Fittings are packed for export with plastic end caps protecting the bevels, rust-preventive or VCI wrapping on carbon and alloy steel, and seaworthy wooden cases; marking, tagging and packing to your specification are available on request.
Why Choose Raaj Fittings for Stub Ends?
Raaj Sagar Steels has supplied piping components since 2003 and today manufactures buttweld fittings at two plants in India for buyers in the Middle East, Europe and the Americas.
- Manufactured in-house — Stub ends are made in our own plants, so material, dimensions and delivery stay under our control.
- Ready stock, short lead times — common sizes and grades are held in stock for prompt dispatch; other sizes, grades and specials are manufactured to order.
- Certified quality — ISO 9001:2015, ISO 14001:2015 and ISO 45001:2018 certified; PED 2014/68/EU and IBR supply available, and NACE MR0175 / ISO 15156 material on request.
- 100% material verification — PMI testing on incoming material and EN 10204 3.1 mill test certificates with every order; 3.2 certificates on request.
- Third-party inspection ready — we regularly work with SGS, Bureau Veritas, TÜV and DNV.
- Export documentation — MTCs, certificates of origin, packing lists and inspection reports to suit projects in the GCC, Europe and the Americas.
- Export packing — seaworthy packing with end and face protection, and packing to your specification on request.
- Fast response — our team replies to enquiries within one business day.
Stub Ends — FAQs
A stub end is a short pipe fitting with a flared lip on one end. It is welded to the pipe and used with a loose lap joint flange to make a bolted joint.
Only the stub end touches the fluid, so a low-cost carbon steel flange can be used with stainless or alloy piping. The loose flange also makes alignment and dismantling easy.
Long-pattern stub ends to ASME B16.9 have a longer barrel and are used in process piping. Short-pattern stub ends to MSS SP-43 are shorter and used mainly on light-wall stainless steel.
Type A has a radiused lap to suit a standard lap joint flange, Type B is for use with a slip on flange as the backing flange, and Type C has a lap formed from or fabricated onto pipe.
The gasket sits between the lap faces of the two stub ends. The backing flanges only provide the bolt load.
Yes. We supply stub ends for projects under the European Pressure Equipment Directive (PED 2014/68/EU), and with IBR certification for Indian boiler applications. NACE MR0175 / ISO 15156 compliant material is also available on request for sour service in the Middle East and the Americas.
