Welded tubes are formed from strip or plate, welded longitudinally and then annealed and sized. They are an economical choice where duty is moderate, such as structural, architectural, sanitary and general tubing. Ruby Infra Projects supplies welded stainless steel tubes from 8 mm to 12.7 mm (1/2 inch) outside diameter, in wall thicknesses from 0.5 mm to 1 mm.
Send your grade, size, length and quantity and the team will confirm availability, lead time and a quotation. Material test certificates from Government or NABL-accredited laboratories are provided on every batch, under an ISO 9001:2015 certified quality system.
Sizes are shown in millimetres, with approximate inch equivalents.
| Range | Approx. inches | |
|---|---|---|
| Outside diameter (OD) | 8 mm to 12.7 mm | 0.315 to 0.500 in |
| Wall thickness (WT) | 0.5 mm to 1 mm | 0.020 to 0.039 in |
Other sizes and custom specifications can be discussed; send your drawing or specification with the enquiry.
Grade guidance is general. Confirm the grade with your design engineer or inspector.
| Grade | What it is | Typical use |
|---|---|---|
| 304 | Roughly 18-20% chromium and 8-11% nickel; good general corrosion resistance | General tubing, food, interior and architectural use |
| 304L | Low-carbon 304, carbon limited to about 0.03-0.035%, so welds resist intergranular corrosion | Welded or heat-exposed service |
| 316 / 316L | Adds about 2-3% molybdenum for much better resistance to chlorides and pitting | Marine, coastal, chemical and process environments |
Other grades can be supplied on request.
Both are widely used. The right choice depends on pressure, temperature, inspection requirements and budget.
| Welded | Seamless | |
|---|---|---|
| How it is made | Strip or plate roll-formed and welded longitudinally (commonly TIG or laser), then annealed and sized | Solid billet pierced and drawn or rolled to size, no weld seam |
| Typical duty | Moderate duty where cost matters: structural, architectural, sanitary and general piping | Higher pressure and critical boiler or heat-exchanger duty |
A properly made and annealed welded tube performs comparably to seamless in most corrosive environments. Low-carbon grades (304L, 316L) and correct post-weld cleaning keep the weld zone corrosion-resistant.
State the specification your project or inspector requires.
| Standard | What it covers |
|---|---|
| ASTM A249 | Welded austenitic steel boiler, superheater, heat-exchanger and condenser tubes |
| ASTM A269 | Seamless and welded austenitic stainless steel tubing for general service |
Read more in our blog explainer on ASTM A213, A249, A269 and A312.
Ruby Infra Projects supplies welded stainless steel tubes from 8 mm to 12.7 mm outside diameter in wall thicknesses from 0.5 mm to 1 mm. Send your grade, size, length and quantity for availability, lead time and a quotation.
Welded tubes are formed from strip or plate and welded longitudinally, then usually annealed and sized. They are economical where duty is moderate, such as structural, architectural, sanitary and general piping.
A properly made and annealed welded tube performs comparably to seamless in most corrosive environments. Low-carbon grades (304L, 316L) and correct post-weld cleaning (pickling and passivation) keep the weld zone corrosion-resistant.
The L stands for low carbon, with carbon limited to about 0.03-0.035%. Low carbon reduces chromium carbide formation at welds (sensitisation), which protects against intergranular corrosion in welded or heat-exposed service.
Yes. Material test certificates from Government or NABL-accredited laboratories are provided on every batch. State the certificate format you need when you request a quote.
Yes. Ruby Infra Projects supplies customers outside India as well as within India and holds an Import Export Code (IEC). Send the grade, size range, quantity, destination country or port and shipping terms for a quotation.