dwg AVX-1804 · Products
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Stainless tube, round bar and flat bar are semi-finished long products for machining, welding, bending and fabrication. The specification combines grade, product standard and delivery condition. This includes seamless or welded tube and hot- or cold-finished, pickled, annealed or ground material. These requirements must suit the application, with the material certificate traceable to the piece after cutting.
Also known as: stainless steel tube · stainless steel round bar · stainless flat bar · seamless and welded tube · 316L tube supplier · bar stock for machining
The wrong delivery condition or a certificate that does not match the heat number can delay machining and inspection. Welded tube supplied where seamless was specified is another example. Confirm the material requirements before ordering so the delivered stock can be used and released for the job.
We supply stainless and higher-alloy tube, round bar and flat bar as material in the required lengths. State the grade or application, product form, dimensions and tolerances, and certificate level. We work from a drawing or the application data. Sheet and plate have separate thickness, finish and cutting requirements and are covered on the alloy plate page.
Cut-to-length supply can reduce sawing and offcuts at your workshop. Each piece is marked to keep the grade, heat number and certificate traceable after cutting. Availability and lead time are confirmed at quotation for both stainless and higher alloys.
| Property | Value |
|---|---|
| Long product: tube, round bar and flat bar | |
| 6–168.3 mm (common commercial span); larger as welded tube | |
| typically 1.0–12.5 mm, set by diameter and schedule; seamless or welded | |
| round 6–250 mm Ø; flat bar 20 × 3 mm to 150 × 30 mm (common commercial sizes) | |
| commercial mill lengths, typically 3–6 m; sawn to length on request | |
| tube pickled or bright annealed; bar hot rolled, cold drawn, peeled or ground | |
| 1.4301/304, 1.4404/316L, 1.4541/321, 1.4571/316Ti, 1.4462 Duplex; nickel alloys per order | |
| tube ASTM A312 / A213 / A269, EN 10216-5 / 10217-7; bar ASTM A276 / A479, EN 10088-3 | |
| EN 10204 3.1 on request; 3.2 (mill plus your own or a designated inspector) by arrangement |
Values shown are standard industry ranges for stainless and alloy tube and bar — not a commitment and not a stock statement. The exact specification — form, grade, dimension, tolerance class, delivery condition and certificate level — is confirmed per application after technical review, and availability and lead time are confirmed at quotation.
304 covers dry and mildly corrosive work. Chlorides, acids and welded assemblies move it to 316L; strength plus chlorides moves it to Duplex; high temperature or an aggressive medium moves it to a nickel alloy. If the grade is fixed by your customer's specification, quote it. If it is not, send the medium, its concentration and the design temperature and let the grade follow from those.
State outside diameter, wall thickness, bar diameter, flat-bar width and thickness, or cut length as applicable. Identify critical tolerances and whether dimensions are finished sizes or include machining allowance. These requirements should be agreed before supply.
Welded tube made to a recognised standard can suit many duties. ASTM A312 covers both welded and seamless constructions, but their suitability must be checked against design and customer requirements. Weld quality factors and examination requirements depend on the design. Higher pressure and some sour or cyclic duties may require seamless tube. State the required construction and standard, such as ASTM A312, A213, EN 10216-5 or EN 10217-7.
The starting surface decides what the finishing work costs. Pickled or bright-annealed tube and hot-rolled, cold-drawn, peeled or ground bar are not interchangeable once a hygienic or polished finish is required. State the surface with the certificate level; EN 10204 3.1 is the usual level and is issued with the material, not added to it afterwards.
Standard in 304/304L and 316/316L, the grades that cover most fabrication. 321 and 316Ti for the sensitisation window, Duplex 1.4462 where chlorides and higher strength meet, and nickel alloys such as Inconel, Incoloy, Monel and Hastelloy where the medium demands them. The higher alloys are sourced per order rather than held as a general range; availability, the forms obtainable and lead time for those are confirmed at quotation.
Seamless tube is formed from a solid billet and has no longitudinal weld. Welded tube is formed from strip and welded along the seam, often cold-drawn afterwards. Both are made and tested to their own standards; ASTM A312 covers both constructions; and for a large share of duties the welded grade is accepted at a lower price. It is not a blanket equivalence: pressure design applies a lower weld joint quality factor to the seam unless it is additionally examined, and seamless is specified outright for higher pressure, certain sour or cyclic service, and wherever a customer specification requires it.
304 for dry and mildly corrosive work. 316L where chlorides are present, and the low-carbon grade wherever the part is welded and cannot be solution annealed afterwards. Duplex 1.4462 where chloride resistance has to come with roughly double the minimum yield strength listed for 316L in the EN 10088 tables, which often lets you drop a wall thickness. Send the medium, the concentration and the temperature; the grade is a consequence of those, not a preference.
Yes. Give the cut length, the quantity per length and the tolerance you need on it; a saw cut and a machined face are different things and priced differently. Marking is transferred to each cut piece, so a bar that leaves as one length and arrives as six is still six traceable pieces.
EN 10204 3.1 on request: issued by the mill's own inspection representative, independent of the production department, with test results on the material delivered and traceable to the heat. A 3.2 certificate; the same document additionally countersigned by an inspector acting for you or designated by regulation; by arrangement. Ask for the level at RFQ: a certificate is issued with the material, and adding it after the material has shipped is rarely possible.
The product standard sets them; ASTM A312 and EN 10216-5 for tube, EN 10088-3 and ASTM A276 for bar. If your part needs tighter than the standard, say which dimension and by how much. That either moves you to a different delivery condition, such as cold-drawn, peeled or ground bar, or it is handled with machining allowance.
It depends on what happens after us. Pickled tube is the matt grey standard after annealing; bright annealed is smoother and the usual choice where the bore stays in contact with the product, as in hygienic and instrument lines. Bar runs hot rolled, cold drawn, peeled or ground, in roughly that order of surface quality and tolerance. If the part is to be polished, passivated or run in hygienic service, say so; the starting surface decides most of that cost.
We do not publish a stock list, because a published list is out of date the day after it is written. Common forms in 304 and 316L are widely available commercial material, and the position for your exact form, grade and dimension is confirmed at quotation. Higher alloys are sourced per order. If a shutdown date depends on it, mark the RFQ urgent and we plan around the window.
Form, grade or the duty that decides it, the dimensions with the tolerance that matters, cut length and quantity, the product standard if your specification names one, the surface condition and the certificate level. A drawing or a marked-up spec extract answers most of that at once, and it removes a round of questions before you get a price.
RFQ
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