Categories
- Round bars
- Seamless tubes and hollow bars
- Seamless stainless tubes 1.4301 / 1.4306 / 1.4307 / 304 / 304L
- Seamless stainless tubes 1.4401 / 1.4404 / 316 / 316L
- Seamless stainless tubes 1.4539
- Seamless stainless tubes 1.4541 / 1.4878 / 321 / 321H / 08Cr18Ni10Ti
- Seamless stainless tubes 1.4571 / 316Ti
- Seamless stainless tubes 1.4912/TP347H
- Seamless stainless tubes and hollow bars duplex steel
- Seamless stainless tubes and hollow bars in superduplex grade
- Seamless stainless steel tubes in heat resistant grade
- Seamless stainless steel tubes of martensitic steel 1H13 / 1.4006 / AISI410
- Seamless stainless steel tubes in superaustenitic steel
- Seamless stainless ferritic steel tubes 1.4510 / OH17T / X3CrTi17, 0H17T, AISI 430Ti
- Seamless stainless steel tubes in steel Alloy 800H
- Other
- Fittings
- Sheets
Item length
Outside diameter (OD)
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9.53 mm
(22)
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DN6 / 12.00 mm
(22)
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DN15 / 21.30 mm
(66)
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DN20 / 25.00 mm
(22)
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DN20 / 26.90 mm
(44)
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DN25 / 33.70 mm
(66)
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DN32 / 38.00 mm
(21)
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DN32 / 42.40 mm
(44)
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DN40 / 48.26 mm
(13)
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DN40 / 48.30 mm
(44)
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DN50 / 60.30 mm
(44)
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DN50 / 60.33 mm
(57)
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DN65 / 71.00 mm
(22)
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DN65 / 73.00 mm
(22)
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DN65 / 73.03 mm
(22)
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DN65 / 76.10 mm
(22)
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DN80 / 88.90 mm
(57)
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DN125 / 125.00 mm
(22)
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DN150 / 168.30 mm
(22)
Wall thickness (WT)
Steel grade
Availability
Seamless stainless tubes and hollow bars duplex steel - stainless steel
Stainless steel seamless tube Ø 9,53 mm x 0,89 mm in grade duplex S31803 / S32205 100cm
- Length: 100 cm
- Outside diameter (OD): 9.53 mm
- Wall thickness (WT): 0.89 mm
- Steel grade: S31803 / S32205
Availability:
available
Dispatched within: 3 days
Stainless steel seamless tube DN15 Ø 21,3 mm x 2 mm in grade duplex duplex 1.4462 100cm
- Length: 100cm
- Outside diameter (OD): 21.3 mm
- Wall thickness (WT): 2 mm
- Steel grade: 1.4462
Availability:
available
Dispatched within: 3 days
Stainless steel seamless tube DN15 Ø 21,3 mm x 2,6 mm in grade duplex duplex 1.4462 100cm
- Length: 100cm
- Outside diameter (OD): 21.3 mm
- Wall thickness (WT): 2.6 mm
- Steel grade: 1.4462
Availability:
available
Dispatched within: 3 days
Stainless steel seamless tube DN15 Ø 21,3 mm x 2,9 mm in grade duplex duplex 1.4462 100cm
- Length: 100cm
- Outside diameter (OD): 21.3 mm
- Wall thickness (WT): 2.9 mm
- Steel grade: 1.4462
Availability:
available
Dispatched within: 3 days
Stainless steel seamless tube DN20 Ø 26,9 mm x 2 mm in grade duplex duplex 1.4462 100cm
- Length: 100cm
- Outside diameter (OD): 26.9 mm
- Wall thickness (WT): 2 mm
- Steel grade: 1.4462
Availability:
available
Dispatched within: 3 days
Stainless steel seamless tube DN40 Ø 48,3 mm x 2,9 mm in grade duplex duplex 1.4462 100cm
- Length: 100cm
- Outside diameter (OD): 48.3 mm
- Wall thickness (WT): 2.9 mm
- Steel grade: 1.4462
Availability:
available
Dispatched within: 3 days
Stainless steel seamless tube Ø 9,53 mm x 0,89 mm in grade duplex S31803 / S32205 10cm
- Length: 10 cm
- Outside diameter (OD): 9.53 mm
- Wall thickness (WT): 0.89 mm
- Steel grade: S31803 / S32205
Availability:
available
Dispatched within: 3 days
Stainless steel seamless tube Ø 9,53 mm x 0,89 mm in grade duplex S31803 / S32205 110cm
- Length: 110 cm
- Outside diameter (OD): 9.53 mm
- Wall thickness (WT): 0.89 mm
- Steel grade: S31803 / S32205
Availability:
available
Dispatched within: 3 days
Stainless steel seamless tube Ø 9,53 mm x 0,89 mm in grade duplex S31803 / S32205 120cm
- Length: 120 cm
- Outside diameter (OD): 9.53 mm
- Wall thickness (WT): 0.89 mm
- Steel grade: S31803 / S32205
Availability:
available
Dispatched within: 3 days
Stainless steel seamless tube Ø 9,53 mm x 0,89 mm in grade duplex S31803 / S32205 20cm
- Length: 20 cm
- Outside diameter (OD): 9.53 mm
- Wall thickness (WT): 0.89 mm
- Steel grade: S31803 / S32205
Availability:
available
Dispatched within: 3 days
Stainless steel seamless tube Ø 9,53 mm x 0,89 mm in grade duplex S31803 / S32205 30cm
- Length: 30 cm
- Outside diameter (OD): 9.53 mm
- Wall thickness (WT): 0.89 mm
- Steel grade: S31803 / S32205
Availability:
available
Dispatched within: 3 days
Stainless steel seamless tube Ø 9,53 mm x 0,89 mm in grade duplex S31803 / S32205 40cm
- Length: 40 cm
- Outside diameter (OD): 9.53 mm
- Wall thickness (WT): 0.89 mm
- Steel grade: S31803 / S32205
Availability:
available
Dispatched within: 3 days
Seamless stainless tubes and hollow bars duplex steel — overview
Seamless stainless tubes and hollow bars duplex steel are tubular products made from duplex stainless steel — a family of stainless alloys that combine austenitic and ferritic microstructures. That blend gives duplex grades an attractive mix of properties: higher strength than common austenitic stainless steels (for example 304 or 316), good resistance to pitting and crevice corrosion, and improved resistance to stress corrosion cracking. In plain terms: duplex tubing and hollow bars are chosen when you need robust, corrosion-resistant tubes or thick-walled tubular blanks that are stronger than standard stainless steel.
What are seamless tubes and hollow bars?
Seamless tubes are produced without a longitudinal weld seam. That uninterrupted wall gives better mechanical integrity and often better fatigue performance, which is important for pressure, hydraulic and structural applications. Hollow bars are solid-section bars manufactured with a central bore (also called hollow bar or tubular bar) and are typically used where a thick wall and high mechanical strength are required together with the ability to machine internal features.
Typical duplex grades and designations
Duplex stainless steels are commonly referred to by both common names and technical designations. Examples you will see in the UK and internationally include:
- Duplex 2205 — commonly referenced as 2205 (EN: 1.4462; US/UNS: S32205 / sometimes S31803). This is the most widely used duplex grade for general industrial service.
- Super duplex 2507 — commonly referenced as 2507 (US/UNS: S32750). Super duplex grades offer still higher pitting and crevice corrosion resistance for aggressive marine, chemical and offshore environments.
We use both everyday names (duplex stainless steel, duplex tubing, super duplex) and technical codes (EN, UNS/ASTM) so engineers and buyers can match material specifications precisely.
Where and how duplex seamless tubes and hollow bars are used
Duplex seamless tubes and hollow bars are used across many sectors because of their combined corrosion resistance and strength. Typical applications include:
- Oil & gas and offshore: risers, process lines, subsea components and structural parts exposed to seawater or chloride-rich environments.
- Chemical and petrochemical plants: heat exchangers, pressure vessels, process piping and tanks handling chlorides or caustic solutions.
- Water treatment and desalination: sea-water lines, RO equipment where pitting resistance is essential.
- Marine and shipbuilding: shafts, hydraulic lines, fittings and structural tubes exposed to seawater.
- Food, pharmaceutical and beverage: hygienic piping and process components where corrosion resistance and cleanliness are required (subject to specific hygiene certifications).
- Automotive, engineering and small workshop projects: high-strength shafts, hydraulic components, mandrels and bespoke fabricated parts — from garage-level machining to precision engineering.
- Construction and architecture: structural tubes and balustrades where strength and corrosion resistance are both required.
Benefits and practical considerations
Benefits:
- Higher yield and tensile strength compared with common austenitic grades — useful when lighter or thinner sections are required for the same load.
- Excellent resistance to localised corrosion (pitting and crevice) and improved resistance to stress corrosion cracking.
- Seamless construction offers superior integrity for pressure and fatigue-sensitive applications.
Practical notes: duplex steels are weldable and formable, but they require attention to welding procedure and heat input to preserve the balanced microstructure. Machining duplex materials can be harder than machining 304/316 because of higher strength — suitable tooling and feeds speeds are recommended. For critical applications, always follow the material standards and welding guidelines supplied with the product.
Who buys these products?
Buyers range from fabricators, mechanical and process engineers, and procurement teams in oil & gas, marine, chemical and water industries to smaller engineering shops and hobbyists needing high-strength, corrosion-resistant tubular stock. Our product range is intended to serve both large industrial projects and one-off specialist machining jobs.
What we sell and what we don’t
Our shop specialises exclusively in stainless, heat-resistant and acid-resistant steels — including duplex and super duplex seamless tubes and hollow bars. We do not supply aluminium or plain carbon steels. If you need assistance matching a duplex grade to your specification (EN, UNS/ASTM or project requirement), we can help you choose the most appropriate grade and product form.
Need help selecting the right duplex tubing or hollow bar?
If you're not sure which product or grade fits your application, contact our technical sales team with details such as operating environment (temperature, media, chloride level), mechanical loads, dimensions and any relevant standards. We can advise on grade selection, typical sizes and recommended fabrication practices to help ensure reliable performance in service.