Stainless Steel 304 Capillary Tubes Manufacturer & Supplier
Amardeep Steel Centre specialises in manufacturing and supplying Stainless Steel 304 capillary tubes for precision applications requiring accurate dimensions, consistent wall thickness and reliable corrosion resistance. SS 304 capillary tubes are available in seamless and welded construction and can be supplied to applicable ASTM A213 and ASTM A269 requirements. With good formability, machinability and resistance to many common atmospheric and process environments, grade 304 is widely used for instrumentation, laboratory equipment, medical devices, refrigeration and other precision applications. Products can be supplied with material traceability and EN 10204 3.1 Mill Test Certificates and are exported to customers in more than 40 countries.
Technical Data
Stainless Steel 304 Capillary Tubes Specification
| Specification | Detail |
|---|---|
|
Standard |
ASTM A213, ASTM A269 |
|
Grade |
SS 304, UNS S30400, Werkstoff 1.4301, JIS SUS 304 |
|
Outer diameter |
0.3 mm to 10 mm, larger sizes on request |
|
Wall thickness |
0.08 mm to 1.5 mm |
|
Construction |
Seamless or welded |
|
Length |
Cut length or continuous coil |
|
End finish |
Plain end or bevelled end |
|
Surface finish |
Bright annealed, pickled, polished or electropolished |
|
Certification |
EN 10204 3.1 Mill Test Certificate standard, 3.2 on request |
Chemical Composition of SS 304 Capillary Tube
| Grade | UNS | C max | Mn max | Si max | P max | S max | Cr | Ni |
|---|---|---|---|---|---|---|---|---|
|
304 |
S30400 |
0.08 |
2.00 |
0.75 |
0.045 |
0.030 |
18.0 to 20.0 |
8.0 to 10.5 |
|
304L |
S30403 |
0.03 |
2.00 |
0.75 |
0.045 |
0.030 |
18.0 to 20.0 |
8.0 to 12.0 |
Mechanical Properties of Stainless Steel 304 Capillary Tubes
| Property | Value |
|---|---|
|
Tensile strength, minimum |
515 MPa (75000 psi) |
|
Yield strength, 0.2 percent proof, minimum |
205 MPa (30000 psi) |
|
Elongation in 50 mm, minimum |
35 percent |
|
Hardness, maximum |
92 HRB |
|
Solution annealing temperature |
Approximately 1040 C, followed by rapid cooling |
|
Maximum continuous service temperature |
Approximately 870 C in oxidising atmospheres |
Equivalent Grades for SS 304 Capillary Tube
| Standard | UNS | Werkstoff | EN name | JIS |
|---|---|---|---|---|
|
SS 304 |
S30400 |
1.4301 |
X5CrNi18 10 |
SUS 304 |
Stainless Steel 304 Capillary Tube Dimension Chart
| Outer diameter (mm) | Wall thickness (mm) | Inner diameter (mm) |
|---|---|---|
|
0.30 |
0.08 |
0.14 |
|
0.50 |
0.10 |
0.30 |
|
0.80 |
0.15 |
0.50 |
|
1.00 |
0.20 |
0.60 |
|
1.60 |
0.25 |
1.10 |
|
2.00 |
0.30 |
1.40 |
|
3.00 |
0.50 |
2.00 |
|
4.00 |
0.50 |
3.00 |
|
6.00 |
1.00 |
4.00 |
|
8.00 |
1.00 |
6.00 |
|
10.00 |
1.50 |
7.00 |
Dimensional Tolerances for SS 304 Capillary Tube
| Size range | Outer diameter tolerance | Wall thickness tolerance | Length tolerance |
|---|---|---|---|
|
Up to 2 mm OD |
Plus or minus 0.02 mm |
Plus or minus 10 percent |
Plus 3 mm, minus 0 mm |
|
2 mm to 6 mm OD |
Plus or minus 0.05 mm |
Plus or minus 10 percent |
Plus 3 mm, minus 0 mm |
|
6 mm to 10 mm OD |
Plus or minus 0.08 mm |
Plus or minus 10 percent |
Plus 3 mm, minus 0 mm |
SS 304 Capillary Tube Working Pressure Guide
| Outer diameter (mm) | Wall thickness (mm) | Indicative working pressure (bar) |
|---|---|---|
|
1.60 |
0.20 |
Approximately 180 |
|
1.60 |
0.30 |
Approximately 320 |
|
3.00 |
0.50 |
Approximately 370 |
|
6.00 |
1.00 |
Approximately 400 |
|
10.00 |
1.50 |
Approximately 420 |
Applications and Industries for SS 304 Capillary Tubes
- Medical and Healthcare: Hypodermic needles, diagnostic sampling probes, and surgical fluid delivery channels.
- Instrumentation and Controls: Pressure gauge connections, thermal sensors, and microfluidic circuits.
- HVAC and Refrigeration: Refrigerant metering devices and expansion valve capillary lines.
- Laboratory and Analytics: Chromatography columns, gas distribution lines, and micro sampling loops.
Get a Quote for Stainless Steel 304 Capillary Tubes
Amardeep Steel Centre supplies stainless steel 304 capillary tubes with complete documentation, including EN 10204 3.1. Request a quote with your outer diameter, wall thickness and quantity, and our team will confirm price and availability the same working day.
Frequently Asked Questions About Stainless Steel 304 Capillary Tubes
What is a stainless steel 304 capillary tube?
It is a fine bore precision tube, generally under about 10 mm outer diameter, made from grade 304 stainless steel and held to a tight dimensional tolerance on outer diameter, inner diameter and wall thickness. It is used for accurate, low volume flow in sensing, measurement and dosing duty rather than general fluid transport.
What is the difference between SS 304 capillary tubes and normal SS 304 tubes?
A capillary tube is generally under about 10 mm outer diameter with a thin wall and very tight dimensional tolerance, built for precision measurement. A normal tube or pipe is larger, carries a heavier wall for the same duty and is intended for general fluid or gas transport rather than accurate low volume flow.
Is SS 304 capillary tube always seamless?
No. Both seamless and welded construction are manufactured and used across the industry. Seamless tube is drawn from solid billet with no weld line and carries a higher pressure rating. Welded tube is more economical and suits general instrumentation and signal duty.
What sizes are available in stainless steel 304 capillary tube?
We stock outer diameters from around 0.3 mm up to 10 mm, with wall thicknesses from about 0.08 mm to 1.5 mm, in cut lengths or continuous coil, across both seamless and welded construction.
What is the maximum working pressure for SS 304 capillary tubing?
Working pressure depends on the specific outer diameter and wall thickness combination rather than being one fixed figure. Wall thickness affects pressure capability far more than outer diameter does, so a heavier wall in the same size will carry noticeably more pressure. Confirm the exact rating for your combination before specifying a pressure critical system.
Which industries use stainless steel 304 capillary tubes?
Instrumentation and pressure sensing, HPLC and laboratory analytical equipment, medical devices, refrigeration and HVAC expansion, general process instrumentation and automotive sensing all commonly use SS 304 capillary tube wherever chloride exposure is not a concern.
Related Products
304 family: SS 304 Seamless Capillary Tubes, SS 304L Pipes & Tubes, SS 304 Micro Tubing, SS 304 Coil Tubing Manufacturer
