Stainless Steel Seamless Micro Tubes Manufacturer in India
Modern high-precision businesses have been using seamless stainless steel micro tubes that provide unmatched durability, zero leakage, and precise flow control for applications that require special engineering. Made without longitudinal seams, these tiny-diameter tubes boast excellent structural integrity and incredible pressure endurance while being used in medical equipment, aviation manufacturing, and testing ready-made products. Offering both general-purpose Grade 304 and molybdenum-strengthened Grade 316, seamless micro-diameter tubes serve different purposes, from delivery needle packages to flow pathways. These tiny but powerful tubes help to create innovative technologies in every case that requires zero failure tolerance. Amardeep Steel manufactures high-quality stainless steel seamless micro tubes engineered for critical applications where precision, tight dimensional tolerances, and structural integrity are essential.
What Are Stainless Steel Seamless Micro Tubes?
Stainless steel seamless micro tubing refers to an innovative class of tubular substances -- ultrathin tubes made without a welded seam. Unlike similar manufacturing products referred to as Nominal Pipe Size (NPS), these tubes are measured in terms of fractional or metric measurements. The Stubs Iron Wire Gauge (Birmingham Gauge) system is applied in the process of classifying them. What makes the difference is that the bigger the gauge number, the smaller the tube diameter.
Coming back to the production process, the technology of producing these tubes is called multi-pass cold drawing and redrawing based on the technique of using internal floating mandrels. During this process, one can create an exceptionally smooth internal surface in terms of surface finishing and structural grain micro-homogeneity of the material in its entirety. As a result of this production process, there is neither a welded seam nor a heated area, so the risk of line defects appears to be significantly reduced.
Technical Data
Specifications for SS Seamless Micro Tubes
| Specification Parameter | Value Range and Options |
|---|---|
| Outer Diameter Range | 0.2 mm to 6.35 mm (0.008 inches to 0.250 inches) |
| Wall Thickness Range | 0.05 mm to 1.2 mm |
| Manufacturing Standards | ASTM A632, ASTM A269, ASTM A213, DIN 17458 |
| Material Grades | SS 304, 304L, 316, 316L, 317L, 321, 347, 904L, Duplex 2205 |
| Outer Diameter Tolerance | Plus or minus 0.02 mm to plus or minus 0.05 mm |
| Surface Finish | Bright Annealed (BA), Annealed and Pickled (AP), Electropolished (EP) |
| Inner Bore Roughness | Ra less than or equal to 0.4 microns (EP finish down to 0.2 microns) |
| Delivery Conditions | Soft Annealed, Half Hard, Full Hard |
Chemical Composition of Stainless Steel Seamless Micro Tubing
| Material Grade | Carbon (C) | Manganese (Mn) | Silicon (Si) | Phosphorus (P) | Sulfur (S) | Chromium (Cr) | Nickel (Ni) | Molybdenum (Mo) | OtherElements |
|---|---|---|---|---|---|---|---|---|---|
| SS 304 | 0.08 max | 2.00 max | 0.75 max | 0.045 max | 0.030 max | 18.00 - 20.00 | 8.00 - 10.50 | ||
| SS 304L | 0.030 max | 2.00 max | 0.75 max | 0.045 max | 0.030 max | 18.00 - 20.00 | 8.00 - 12.00 | ||
| SS 316 | 0.08 max | 2.00 max | 0.75 max | 0.045 max | 0.030 max | 16.00 - 18.00 | 10.00 - 14.00 | 2.00 - 3.00 | |
| SS 316L | 0.030 max | 2.00 max | 0.75 max | 0.045 max | 0.030 max | 16.00 - 18.00 | 10.00 - 14.00 | 2.00 - 3.00 | |
| SS 321 | 0.08 max | 2.00 max | 0.75 max | 0.045 max | 0.030 max | 17.00 - 19.00 | 9.00 - 12.00 | Ti: 5x(C+N) min | |
| SS 904L | 0.020 max | 2.00 max | 1.00 max | 0.045 max | 0.035 max | 19.00 - 23.00 | 23.00 - 28.00 | 4.00 - 5.00 | Cu: 1.00 - 2.00 |
Values in percent per ASTM A213 and ASTM A269.
Mechanical Properties of Stainless Steel Seamless Micro Tubes
| Material Grade | Tensile Strength (MPa) min | Yield Strength 0.2% Proof (MPa) min | Elongation in 2 inches (%) min | Hardness (HRB) max |
|---|---|---|---|---|
| SS 304 | 515 | 205 | 35 | 90 |
| SS 304L | 485 | 170 | 35 | 90 |
| SS 316 | 515 | 205 | 35 | 90 |
| SS 316L | 485 | 170 | 35 | 90 |
| SS 321 | 515 | 205 | 35 | 90 |
| SS 904L | 490 | 220 | 35 | 90 |
Testing and Quality Assurance
- Chemical Composition Analysis: Every heat of stainless steel seamless micro tube is tested to verify its chemical composition.
- Mechanical Testing: Includes tensile strength testing, yield strength testing and hardness testing.
- Hydrostatic Testing: Hydrostatic testing is done to check for integrity and pressure resistance.
- Eddy Current Testing: This test is performed to identify surface and near-surface defects.
- Ultrasonic Testing: This is a method used for discovering internal and subsurface defects.
- Dimensional Inspection: Tubes undergo full dimensional inspection to ensure compliance with specified OD, ID, wall thickness, and length requirements.
- Visual Inspection: Each tube is visually inspected for surface defects, workmanship, and overall quality.
- EN 10204 3.1 Mill Test Certificate (MTC): Each shipment is supplied with an MTC detailing heat numbers, chemical composition, and mechanical test results.
Main Uses Of Seamless Stainless Steel Micro Tubes
- Medical Instruments and Surgical Equipment: Surgical needles, tubes for endoscopy, cannula tubing, and biopsy instruments rely on the use of small micro pipes and compatibility with living beings.
- Analytical HPLC: For liquid chromatography columns, tight tolerances for the tube’s inside diameter and polished inner surface are needed in order to keep flows in all parts of the chromatography column equal.
- Instruments and Sensors: Micro tubes are also utilised as pressure-transmitting pipes and temperature-sensing devices for system components.
- Wind & Automotive: Fuel lines that work at high pressure and hydraulic micro tubes are subjected to thermal effects.
Related Products
- high temperature stainless steel tubing
- 316L stainless steel pipes and tubes
- 304L stainless steel tubing
Frequently Asked Questions
What is the minimum outer diameter available for seamless micro tubes?
We supply stainless steel seamless micro tubes down to an outer diameter of 0.2 mm. Custom micro bore dimensions can also be produced based on project specifications.
Why choose seamless micro tubes instead of welded micro tubing?
Seamless micro tubes lack longitudinal weld seams, providing higher burst pressure limits, superior resistance to mechanical fatigue, and zero risk of seam corrosion during high pressure or critical fluid transport.
Which grade is best suited for medical or pharmaceutical micro tubing?
Stainless steel 316L is widely preferred for medical devices, implants, and pharmaceutical fluid handling due to its low carbon content, excellent biocompatibility, and resistance to chloride corrosion.
Can micro tubes be supplied in coils or straight lengths?
Yes, depending on the outer diameter and wall thickness, micro tubing can be supplied in continuous coils for long-distance instrumentation lines or cut to specific straight lengths with burr-free ends.
What surface finishes are available for the inner bore of micro tubing?
Our micro tubes are available with Bright Annealed (BA) or Electropolished (EP) internal surface finishes, achieving internal bore roughness levels as low as Ra 0.2 to 0.4 microns for smooth fluid movement.
Every order ships from our Mumbai facility complete with EN 10204 3.1 Mill Test Certificates detailing heat numbers, chemical composition analysis, and mechanical test results. For standard dimensional requirements, request a Quote .
