Stainless Steel Welded Micro Tubes Manufacturer and Supplier
Engineered for extreme precision and miniaturised flow paths, stainless steel welded micro tubes are thin, ultra-small-diameter precision tubes designed to deliver unmatched durability and dependable performance across medical, aerospace, and instrumentation applications. Produced via advanced longitudinal welding and continuous cold drawing, these small-diameter welded tubes provide a highly cost-effective alternative to seamless tubing while offering exceptional wall uniformity and bore stability. Available in general-purpose SS 304 (18 percent Cr, 8 percent Ni) and molybdenum-enhanced SS 316 for superior chloride and marine corrosion resistance, welded micro tubes fulfill distinct needs in high-pressure fluid delivery and structural designs where space is restricted. Amardeep Steel Centre LLP is a recognised global manufacturer and supplier of high-precision stainless steel welded micro tubes. We supply custom sizes, standard gauge stock, and tight tolerance micro welded tubing tailored to your exact engineering requirements.
What is a Stainless Steel Welded Micro Tube?
A welded micro tube made of stainless steel is a type of precision tube with a tiny diameter that is made to serve specific purposes such as controlling the flow of fluids, providing structural support and instrumentation. Micro tubing differs from piping in that it has very thin walls and extremely small diameters, from millimetres to a quarter of an inch.
The manufacturing process begins with high-purity continuous rolled steel strip. This strip is carefully formed into a continuous tubular shape and joined longitudinally using automated advanced welding techniques such as TIG welding or laser welding. Following the primary welding phase, the tube undergoes continuous cold drawing over internal mandrels and through precision dies. This redrawing process refines the grain structure, eliminates the weld seam profile, smooths the internal and external surfaces, and achieves exact final gauge dimensions.
Technical Data
Specifications of Small Diameter Welded Stainless Steel Tubes
| Specification Parameter | Technical Details |
|---|---|
Outer Diameter (OD) Range | 0.20 mm to 6.35 mm (0.008 inch to 0.250 inch) |
Wall Thickness (WT) Range | 0.05 mm to 1.00 mm (0.002 inch to 0.040 inch) |
Dimensional Tolerances | OD tolerance to +/- 0.013 mm (+/- 0.0005 inch); Wall tolerance to +/- 10% |
Manufacturing Process | Welded and Cold Redrawn (WLD), Bright Annealed |
Manufacturing Standards | ASTM A269, ASTM A249, ASTM A632, ASTM A554 |
Material Grades | SS 304, SS 304L, SS 304H, SS 316, SS 316L, SS 316Ti, Custom Austenitic Alloys |
Surface Finishes | Bright Annealed (BA), Passivated, Electropolished, Mechanical Polish (up to 20 Ra ID / 32 Ra OD) |
Delivery Conditions | Straight lengths (1 meter to 6 meters) or continuous coils (up to 1000 metres) |
Quality Certification | EN 10204 3.1 Mill Test Certificate (MTC) supplied with all consignments |
Chemical Composition of SS Welded Micro Tubes
| Grade | Chromium (Cr) | Nickel (Ni) | Molybdenum (Mo) | Carbon (C) Max | Manganese (Mn) Max | Silicon (Si) Max | Phosphorus (P) Max | Sulfur (S) Max | Iron (Fe) |
|---|---|---|---|---|---|---|---|---|---|
SS 304 | 18.00 - 20.00% | 8.00 - 11.00% | - | 0.08% | 2.00% | 0.75% | 0.045% | 0.030% | Balance |
SS 304L | 18.00 - 20.00% | 8.00 - 12.00% | - | 0.03% | 2.00% | 0.75% | 0.045% | 0.030% | Balance |
SS 316 | 16.00 - 18.00% | 10.00 - 14.00% | 2.00 - 3.00% | 0.08% | 2.00% | 0.75% | 0.045% | 0.030% | Balance |
SS 316L | 16.00 - 18.00% | 10.00 - 14.00% | 2.00 - 3.00% | 0.03% | 2.00% | 0.75% | 0.045% | 0.030% | Balance |
SS 316Ti | 16.00 - 18.00% | 10.00 - 14.00% | 2.00 - 3.00% | 0.08% | 2.00% | 0.75% | 0.045% | 0.030% | Balance (Ti 5x C min) |
Mechanical and Physical Properties of ASTM A269 Welded Micro Tubes
| Material Grade | Tensile Strength (Min) | Yield Strength 0.2% Offset (Min) | Elongation in 2 Inches (Min) | Hardness Rockwell B (Max) | Density (g/cm³) | Melting Point (°C) |
|---|---|---|---|---|---|---|
SS 304 | 515 MPa (75,000 PSI) | 205 MPa (30,000 PSI) | 35% | 92 HRB | 8.00 g/cm³ | 1400 °C |
SS 304L | 485 MPa (70,000 PSI) | 170 MPa (25,000 PSI) | 35% | 90 HRB | 8.00 g/cm³ | 1400 °C |
SS 316 | 515 MPa (75,000 PSI) | 205 MPa (30,000 PSI) | 35% | 95 HRB | 8.00 g/cm³ | 1399 °C |
SS 316L | 485 MPa (70,000 PSI) | 170 MPa (25,000 PSI) | 35% | 90 HRB | 8.00 g/cm³ | 1399 °C |
SS 316Ti | 515 MPa (75,000 PSI) | 205 MPa (30,000 PSI) | 35% | 95 HRB | 8.00 g/cm³ | 1400 °C |
Working Pressure Ratings Table for Stainless Steel Welded Micro Tubes
| Outer Diameter (OD) | Wall Thickness (WT) | Calculated Working Pressure (PSI) | Calculated Working Pressure (Bar) | Theoretical Burst Pressure (PSI) |
|---|---|---|---|---|
0.50 mm (0.020″) | 0.10 mm (0.004″) | 6,000 PSI | 413 Bar | 24,000 PSI |
0.50 mm (0.020″) | 0.15 mm (0.006″) | 9,000 PSI | 620 Bar | 36,000 PSI |
1.00 mm (0.039″) | 0.15 mm (0.006″) | 4,500 PSI | 310 Bar | 18,000 PSI |
1.00 mm (0.039″) | 0.20 mm (0.008″) | 6,000 PSI | 413 Bar | 24,000 PSI |
1.58 mm (1/16″ or 0.062″) | 0.25 mm (0.010″) | 5,600 PSI | 386 Bar | 22,400 PSI |
1.58 mm (1/16″ or 0.062″) | 0.50 mm (0.020″) | 12,000 PSI | 827 Bar | 48,000 PSI |
3.18 mm (1/8″ or 0.125″) | 0.50 mm (0.020″) | 5,400 PSI | 372 Bar | 21,600 PSI |
3.18 mm (1/8″ or 0.125″) | 0.89 mm (0.035″) | 10,900 PSI | 751 Bar | 43,600 PSI |
6.35 mm (1/4″ or 0.250″) | 0.89 mm (0.035″) | 5,100 PSI | 351 Bar | 20,400 PSI |
6.35 mm (1/4″ or 0.250″) | 1.00 mm (0.040″) | 6,000 PSI | 413 Bar | 24,000 PSI |
Manufacturing Standards & Dimensional Tolerances of Small Diameter Welded SS Tubes
| Parameter | Standard Precision | Ultra-High Precision (Custom) | Applicable International Standards |
|---|---|---|---|
Outer Diameter (OD) | ± 0.05 mm (± 0.002″) | ± 0.013 mm (± 0.0005″) | ASTM A269, ASTM A249, ASTM A632 |
Wall Thickness (WT) | ± 10% of nominal wall | ± 5% of nominal wall | ASTM A269, ASTM A632 |
Cut Length Tolerance | ± 1.0 mm (Standard cut) | ± 0.2 mm (Precision burr-free cut) | ISO 2768-m |
Surface Roughness (ID) | Ra 0.8 µm (32 µin) | Ra 0.4 µm (16 µin) Electropolished | ASTM A270 Sanitary Grade |
Straightness | 1.0 mm per meter | 0.5 mm per meter | EN 10217-7 |
Industrial Applications of Welded SS Micro Tubes
Given their mechanical strength, exact size, and dependable resistance to corrosion, our stainless steel micro tubes play an important role in various sectors of the economy.
- Medical and Laboratory Equipment: Used in the making of the fluid delivery needle, sample probe, chromatography column, and diagnostic instruments.
- Aerospace and Defense: Applied in hydraulic control lines, fuel injection nozzles, and environmental sensors' bodies.
- Automotive Systems: Used to manufacture the exhaust sensor tube, fuel pipe systems, and precision fluid injectors.
- Industrial Process Control: Applied in heat exchangers, micro boilers, pressure transmitter lines, and capillary measurement devices. Learn more about high-performance industrial setups through our technical article on stainless steel pipe fittings for high-temperature industrial applications.
Frequently Asked Questions
What is a welded SS micro tube?
A welded SS micro tube is a precision small-diameter tube manufactured by longitudinally welding a stainless steel strip, such as SS 304 or SS 316, followed by cold drawing over internal mandrels to achieve ultra-tight dimensional tolerances and smooth bore finishes.
What is the difference between seamless and welded micro tubing?
Welded micro tubing offers superior wall thickness uniformity, better concentricity, and a more cost-effective manufacturing process compared to seamless micro tubing, while meeting identical pressure and tolerance standards after cold redrawing.
What standards govern ASTM A269 welded micro tubes?
ASTM A269 covers nominal wall thickness stainless steel tubing for general service, requiring specific hydrostatic or nondestructive electric testing, chemical composition compliance, and strict outer diameter tolerances.
What precision tolerances can Amardeep Steel achieve on welded micro tubing?
We achieve outer diameter tolerances as tight as +/- 0.013 mm or +/- 0.0005 inch and wall thickness tolerances within +/- 5% on custom ultra-high precision orders.
What standard delivery conditions and lengths are available?
We supply small diameter welded stainless steel tubes in straight lengths of 1 meter to 6 meters, continuous coils up to 1000 metres, or custom burr-free precision-cut pieces according to your exact drawing requirements.
Request a Quote for Stainless Steel Welded Micro Tubes
Our sales and technical teams are ready to supply high-quality stainless steel welded micro tubes tailored to your custom specifications. Contact our team today for competitive pricing and worldwide delivery schedules.
