{"id":1867,"date":"2026-05-25T05:35:02","date_gmt":"2026-05-25T05:35:02","guid":{"rendered":"http:\/\/www.capillarytubing.net\/?product=304-capillary-tube-od-38-00mm-id-30-00mm-wt-4-00mm"},"modified":"2026-05-25T05:35:02","modified_gmt":"2026-05-25T05:35:02","slug":"304-capillary-tube-od-38-00mm-id-30-00mm-wt-4-00mm","status":"publish","type":"product","link":"https:\/\/www.capillarytubing.net\/index.php\/product\/304-capillary-tube-od-38-00mm-id-30-00mm-wt-4-00mm\/","title":{"rendered":"Precision 304 Stainless Steel Capillary Tube | 38.00mm OD x 30.00mm ID | Thin Wall 4.00mm"},"content":{"rendered":"

\"304<\/p>\n

304 Stainless Steel Capillary Tube \u2013 38.00mm OD x 30.00mm ID x 4.00mm Wall<\/h1>\n
\n

Welcome to our detailed product page for the 304 Stainless Steel Capillary Tube \u2013 38.00mm OD x 30.00mm ID x 4.00mm Wall<\/strong>. This precision-engineered capillary tube is manufactured from premium 304 stainless steel (UNS S30400)<\/strong>, delivering exceptional dimensional accuracy, superior corrosion resistance, and reliable mechanical performance for your most demanding applications.<\/p>\n

At Capillary Tubing Network<\/strong>, we combine advanced cold-drawing technology with stringent quality control to produce micro-tubing that meets the tightest specifications. Whether you require components for medical devices, analytical instruments, or industrial fluid systems, this 304 seamless precision tube<\/strong> product offers the precision and consistency you need.<\/p>\n<\/div>\n

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I. Detailed Product Specifications<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Parameter<\/th>\nValue<\/th>\nTolerance \/ Standard<\/th>\n<\/tr>\n<\/thead>\n
Material Grade<\/strong><\/td>\n304 Stainless Steel (UNS S30400)<\/td>\nASTM A269 \/ A213<\/td>\n<\/tr>\n
Outer Diameter (OD)<\/strong><\/td>\n38.00 mm<\/td>\n\u00b10.01 mm (ISO 2768-f)<\/td>\n<\/tr>\n
Inner Diameter (ID)<\/strong><\/td>\n30.00 mm<\/td>\n\u00b10.01 mm<\/td>\n<\/tr>\n
Wall Thickness (WT)<\/strong><\/td>\n4.00 mm<\/td>\n\u00b10.01 mm<\/td>\n<\/tr>\n
Wall-to-OD Ratio<\/strong><\/td>\n10.5%<\/td>\nThin wall design<\/td>\n<\/tr>\n
Inner Cross-Section Area<\/strong><\/td>\n706.8578 mm\u00b2<\/td>\nFlow capacity: Excellent<\/td>\n<\/tr>\n
Available Length<\/strong><\/td>\nCustom cut (up to 2500 mm)<\/td>\n\u00b10.01 mm (laser precision)<\/td>\n<\/tr>\n
Surface Finish<\/strong><\/td>\nBright Annealed \/ Electropolished<\/td>\nRa \u2264 0.4 \u03bcm (optional Ra \u2264 0.2 \u03bcm)<\/td>\n<\/tr>\n
Straightness<\/strong><\/td>\n\u2264 0.5 mm \/ 1000 mm<\/td>\nASTM A269<\/td>\n<\/tr>\n
End Finish<\/strong><\/td>\nBurr-free, square cut<\/td>\n\u2264 0.05 mm end burr<\/td>\n<\/tr>\n
Packaging<\/strong><\/td>\nPlastic capped \/ Vacuum sealed<\/td>\nAnti-contamination<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

—<\/p>\n

II. Chemical Composition (Weight %)<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Element<\/th>\nPercentage (%)<\/th>\nDescription<\/th>\n<\/tr>\n<\/thead>\n
Carbon (C)<\/strong><\/td>\n\u2264 0.08<\/td>\nStandard carbon content<\/td>\n<\/tr>\n
Chromium (Cr)<\/strong><\/td>\n18.0 – 20.0<\/td>\nPrimary corrosion resistance<\/td>\n<\/tr>\n
Nickel (Ni)<\/strong><\/td>\n8.0 – 10.5<\/td>\nAustenitic structure stabilizer<\/td>\n<\/tr>\n
Manganese (Mn)<\/strong><\/td>\n\u2264 2.00<\/td>\nDeoxidizer and strength enhancer<\/td>\n<\/tr>\n
Silicon (Si)<\/strong><\/td>\n\u2264 1.00<\/td>\nImproves scaling resistance<\/td>\n<\/tr>\n
Phosphorus (P)<\/strong><\/td>\n\u2264 0.045<\/td>\nControlled for ductility<\/td>\n<\/tr>\n
Sulfur (S)<\/strong><\/td>\n\u2264 0.030<\/td>\nControlled for machinability<\/td>\n<\/tr>\n
Nitrogen (N)<\/strong><\/td>\n\u2264 0.10<\/td>\nStrengthens austenitic structure<\/td>\n<\/tr>\n
Iron (Fe)<\/strong><\/td>\nBalance<\/td>\nBase material<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

—<\/p>\n

III. Mechanical Properties<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n\n
Property<\/th>\nValue<\/th>\nUnit<\/th>\nTest Standard<\/th>\nNotes<\/th>\n<\/tr>\n<\/thead>\n
Tensile Strength<\/strong><\/td>\n515 \u2013 690<\/td>\nMPa<\/td>\nASTM E8<\/td>\nMeasured at room temperature<\/td>\n<\/tr>\n
Yield Strength (0.2% Offset)<\/strong><\/td>\n\u2265 205<\/td>\nMPa<\/td>\nASTM E8<\/td>\nCold drawn condition<\/td>\n<\/tr>\n
Elongation at Break<\/strong><\/td>\n\u2265 35 \u2013 45<\/td>\n%<\/td>\nASTM E8<\/td>\n50 mm gauge length<\/td>\n<\/tr>\n
Hardness<\/strong><\/td>\n\u2264 92<\/td>\nHRB<\/td>\nASTM E18<\/td>\nRockwell B scale<\/td>\n<\/tr>\n
Modulus of Elasticity<\/strong><\/td>\n193 \u2013 200<\/td>\nGPa<\/td>\nASTM E111<\/td>\nTypical for austenitic SS<\/td>\n<\/tr>\n
Poisson’s Ratio<\/strong><\/td>\n0.27 \u2013 0.30<\/td>\n–<\/td>\nASTM E132<\/td>\n–<\/td>\n<\/tr>\n
Density<\/strong><\/td>\n7.90 \u2013 8.00<\/td>\ng\/cm\u00b3<\/td>\nASTM A269<\/td>\nAt 20\u00b0C<\/td>\n<\/tr>\n
Thermal Expansion<\/strong><\/td>\n17.3<\/td>\n\u03bcm\/m\u00b7\u00b0C<\/td>\nASTM E831<\/td>\n20\u00b0C \u2013 100\u00b0C<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

—<\/p>\n

IV. Dimensional Tolerance & Quality Assurance<\/h2>\n\n\n\n\n\n\n\n\n
OD Range<\/th>\nInspection Frequency<\/th>\nInspection Method<\/th>\n<\/tr>\n<\/thead>\n
0.25 mm \u2013 0.50 mm<\/strong><\/td>\n100%<\/td>\nLaser micrometer<\/td>\n<\/tr>\n
0.50 mm \u2013 1.00 mm<\/strong><\/td>\n100%<\/td>\nLaser micrometer<\/td>\n<\/tr>\n
1.00 mm \u2013 3.00 mm<\/strong><\/td>\n100%<\/td>\nDigital caliper + micrometer<\/td>\n<\/tr>\n
3.00 mm \u2013 6.00 mm<\/strong><\/td>\nBatch \u00b110%<\/td>\nDigital caliper<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

All tubes undergo 100% dimensional verification<\/strong> with traceable calibration. Each batch includes chemical and mechanical certification upon request.<\/p>\n

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V. Surface Finish Options<\/h2>\n\n\n\n\n\n\n\n\n
Finish Type<\/th>\nRa Value<\/th>\nApplication<\/th>\nProcess<\/th>\n<\/tr>\n<\/thead>\n
Bright Annealed<\/strong><\/td>\nRa \u2264 0.4 \u03bcm<\/td>\nGeneral purpose, medical<\/td>\nAnnealing in controlled atmosphere<\/td>\n<\/tr>\n
Electropolished<\/strong><\/td>\nRa \u2264 0.2 \u03bcm<\/td>\nPharmaceutical, semiconductor<\/td>\nElectrochemical polishing<\/td>\n<\/tr>\n
Mechanical Polish<\/strong><\/td>\nRa \u2264 0.3 \u03bcm<\/td>\nIndustrial, automotive<\/td>\nMechanical buffing<\/td>\n<\/tr>\n
Passivated<\/strong><\/td>\nAs-drawn<\/td>\nCorrosion critical<\/td>\nNitric acid passivation per ASTM A967<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

—<\/p>\n

VI. Key Features & Advantages<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n\n
Feature<\/th>\nSpecification<\/th>\nBenefit to Customer<\/th>\n<\/tr>\n<\/thead>\n
Ultra-Fine OD<\/strong><\/td>\n38.00 mm outer diameter<\/td>\nFits into compact assemblies and micro-devices<\/td>\n<\/tr>\n
Thin Wall Design<\/strong><\/td>\n4.00 mm wall thickness<\/td>\nReduces weight while maintaining structural integrity<\/td>\n<\/tr>\n
High Precision ID<\/strong><\/td>\n30.00 mm \u00b10.01 mm inner bore<\/td>\nConsistent fluid flow with minimal pressure variation<\/td>\n<\/tr>\n
Corrosion Resistance<\/strong><\/td>\nExcellent in oxidizing environments<\/td>\nLonger service life in harsh media<\/td>\n<\/tr>\n
Biocompatibility<\/strong><\/td>\nISO 10993 compliant<\/td>\nSuitable for implant-grade and surgical instruments<\/td>\n<\/tr>\n
Burr-Free Cutting<\/strong><\/td>\nLaser \/ precision cut \u2264 0.05 mm burr<\/td>\nNo secondary deburring required<\/td>\n<\/tr>\n
Lot Traceability<\/strong><\/td>\nFull material traceability<\/td>\nComplete QA documentation available<\/td>\n<\/tr>\n
Custom Lengths<\/strong><\/td>\nCut to exact specification<\/td>\nReduces waste and assembly time<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

—<\/p>\n

VII. Typical Applications & Industry Use Cases<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n\n
Industry<\/th>\nApplication<\/th>\nWhy This Product Excels<\/th>\n<\/tr>\n<\/thead>\n
Medical Devices<\/strong><\/td>\nHypodermic tubing, stent delivery, catheter shafts<\/td>\nPrecision ID ensures accurate fluid delivery; biocompatible surface minimizes tissue reaction<\/td>\n<\/tr>\n
Analytical Instruments<\/strong><\/td>\nHPLC columns, gas chromatography, microfluidics<\/td>\nSmooth ID reduces sample carryover; tight ID tolerance ensures reproducible results<\/td>\n<\/tr>\n
Pharmaceutical Manufacturing<\/strong><\/td>\nDispensing tips, sampling needles, transfer lines<\/td>\nNon-reactive 316L surface maintains sample purity; electropolished option available for CIP\/SIP<\/td>\n<\/tr>\n
Semiconductor<\/strong><\/td>\nGas delivery lines, sensor probes, etching nozzles<\/td>\nUltra-clean surface; electropolished finish minimizes particle entrapment<\/td>\n<\/tr>\n
Aerospace & Defense<\/strong><\/td>\nHydraulic sensing lines, fuel injection, coolant paths<\/td>\nHigh strength-to-weight ratio; excellent fatigue resistance under vibration<\/td>\n<\/tr>\n
Automotive<\/strong><\/td>\nFuel injector nozzles, EGR systems, brake sensing lines<\/td>\nConsistent ID ensures predictable flow rates; corrosion resistant to fuels and coolants<\/td>\n<\/tr>\n
Chemical Processing<\/strong><\/td>\nCatalyst injection, sampling ports, heat exchanger tubes<\/td>\n304 SS resists a wide range of chemicals at elevated temperatures<\/td>\n<\/tr>\n
Research & Development<\/strong><\/td>\nLab-on-a-chip, micro-reactors, experimental setups<\/td>\nCustom dimensions available; small batch quantities supported<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

—<\/p>\n

VIII. CNC Machining & Fabrication Capabilities<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n
Fabrication Service<\/th>\nCapability<\/th>\nTolerance<\/th>\n<\/tr>\n<\/thead>\n
Precision Cutting<\/strong><\/td>\nLaser cutting, abrasive cutting<\/td>\n\u00b10.01 mm<\/td>\n<\/tr>\n
End Forming<\/strong><\/td>\nSwaging, flaring, reducing, expanding<\/td>\n\u00b10.02 mm<\/td>\n<\/tr>\n
Bending<\/strong><\/td>\nCNC mandrel bending up to 180\u00b0<\/td>\n\u00b10.5\u00b0<\/td>\n<\/tr>\n
Drilling \/ Perforation<\/strong><\/td>\nLaser micro-drilling (0.05 mm min.)<\/td>\n\u00b10.005 mm<\/td>\n<\/tr>\n
Welding<\/strong><\/td>\nOrbital TIG, laser welding<\/td>\nFull penetration, no internal flash<\/td>\n<\/tr>\n
Marking<\/strong><\/td>\nLaser engraving, chemical etching<\/td>\nPermanent, legible<\/td>\n<\/tr>\n
Cleaning<\/strong><\/td>\nUltrasonic cleaning, passivation<\/td>\nPer ASTM A967 \/ ISO 13485<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

—<\/p>\n

IX. Available Packaging & Shipping Options<\/h2>\n\n\n\n\n\n\n\n\n
Packaging Type<\/th>\nDescription<\/th>\nBest For<\/th>\n<\/tr>\n<\/thead>\n
Bulk Pack<\/strong><\/td>\nPolybag + carton box<\/td>\nLarge quantity orders<\/td>\n<\/tr>\n
Individual Sleeve<\/strong><\/td>\nHeat-sealed PE sleeve per tube<\/td>\nMedical \/ cleanroom applications<\/td>\n<\/tr>\n
Vacuum Sealed<\/strong><\/td>\nVacuum pack with desiccant<\/td>\nLong-term storage, sensitive components<\/td>\n<\/tr>\n
Custom Kitting<\/strong><\/td>\nPre-sorted by length per kit<\/td>\nAssembly line ready<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Shipping:<\/strong> Worldwide via DHL, FedEx, UPS, or sea freight. Typical lead time: 7\u201315 working days for standard orders.<\/p>\n

—<\/p>\n

X. Comparison: 304 vs Other Common Grades<\/h2>\n\n\n\n\n\n\n\n\n\n\n
Property<\/th>\n304 SS (This Product)<\/th>\n304L SS<\/th>\n316 SS<\/th>\n321 SS<\/th>\n<\/tr>\n<\/thead>\n
Corrosion Resistance<\/strong><\/td>\n\u2605\u2605\u2605\u2605\u2605<\/td>\n\u2605\u2605\u2605\u2605<\/td>\n\u2605\u2605\u2605\u2605\u2605<\/td>\n\u2605\u2605\u2605\u2605<\/td>\n<\/tr>\n
Weldability<\/strong><\/td>\n\u2605\u2605\u2605\u2605\u2605<\/td>\n\u2605\u2605\u2605\u2605\u2605<\/td>\n\u2605\u2605\u2605\u2605<\/td>\n\u2605\u2605\u2605\u2605<\/td>\n<\/tr>\n
Machinability<\/strong><\/td>\n\u2605\u2605\u2605\u2605<\/td>\n\u2605\u2605\u2605\u2605<\/td>\n\u2605\u2605\u2605<\/td>\n\u2605\u2605\u2605<\/td>\n<\/tr>\n
Cost Efficiency<\/strong><\/td>\n\u2605\u2605\u2605\u2605\u2605<\/td>\n\u2605\u2605\u2605\u2605\u2605<\/td>\n\u2605\u2605\u2605<\/td>\n\u2605\u2605\u2605<\/td>\n<\/tr>\n
High Temp Performance<\/strong><\/td>\n\u2605\u2605\u2605<\/td>\n\u2605\u2605\u2605<\/td>\n\u2605\u2605\u2605\u2605<\/td>\n\u2605\u2605\u2605\u2605\u2605<\/td>\n<\/tr>\n
ID Surface Finish<\/strong><\/td>\nRa \u2264 0.4 \u03bcm<\/td>\nRa \u2264 0.6 \u03bcm<\/td>\nRa \u2264 0.4 \u03bcm<\/td>\nRa \u2264 0.6 \u03bcm<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

—<\/p>\n

XI. Quality Control & Certifications<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n
Inspection Stage<\/th>\nParameter<\/th>\nMethod<\/th>\nFrequency<\/th>\nStandard<\/th>\n<\/tr>\n<\/thead>\n
Incoming<\/strong><\/td>\nMaterial certification<\/td>\nMill test report review<\/td>\n100% per lot<\/td>\nEN 10204 3.1<\/td>\n<\/tr>\n
In-Process<\/strong><\/td>\nOD \/ ID \/ WT<\/td>\nLaser micrometer<\/td>\nContinuous<\/td>\nISO 2768<\/td>\n<\/tr>\n
Final<\/strong><\/td>\nFull dimensional check<\/td>\nVision + contact measurement<\/td>\n100%<\/td>\nISO 13485<\/td>\n<\/tr>\n
Surface<\/strong><\/td>\nDefects, burrs, contamination<\/td>\n10\u00d7 optical inspection<\/td>\n100%<\/td>\nASTM A269<\/td>\n<\/tr>\n
Mechanical<\/strong><\/td>\nTensile, hardness<\/td>\nUniversal tester<\/td>\nPer lot<\/td>\nASTM E8 \/ E18<\/td>\n<\/tr>\n
Chemical<\/strong><\/td>\nComposition verification<\/td>\nOES \/ ICP<\/td>\nPer lot<\/td>\nASTM A751<\/td>\n<\/tr>\n
Pressure<\/strong><\/td>\nLeak test<\/td>\nAir \/ hydrostatic<\/td>\nPer request<\/td>\nASME B31.3<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

We provide Certificates of Compliance (CoC)<\/strong> with every order and Material Test Reports (MTR)<\/strong> upon request.<\/p>\n

—<\/p>\n

XII. Why Choose Capillary Tubing Network?<\/h2>\n\n\n\n\n\n\n\n\n\n\n
Advantage<\/th>\nWhat It Means For You<\/th>\n<\/tr>\n<\/thead>\n
15+ Years Experience<\/strong><\/td>\nDeep expertise in micro-tubing manufacturing and precision cutting<\/td>\n<\/tr>\n
ISO-Compliant Facility<\/strong><\/td>\nCertified processes ensure consistent quality from batch to batch<\/td>\n<\/tr>\n
Short Lead Times<\/strong><\/td>\nStandard orders ship within 7\u201315 working days<\/td>\n<\/tr>\n
Custom Manufacturing<\/strong><\/td>\nOEM\/ODM: we produce to your exact drawing and specification<\/td>\n<\/tr>\n
Technical Support<\/strong><\/td>\nEngineers available to help select the optimal grade and dimension<\/td>\n<\/tr>\n
Global Shipping<\/strong><\/td>\nReliable logistics partners serving North America, Europe, and Asia<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

—<\/p>\n

Request a Quote<\/h2>\n
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Ready to order this 304 Stainless Steel Capillary Tube \u2013 38.00mm OD x 30.00mm ID x 4.00mm Wall<\/strong>? Contact us today for pricing, lead time, and custom specification options. Our team will respond within 24 hours<\/strong>.<\/p>\n