Product Description Electro polishing (EP), also known as electrochemical polishing, anodic polishing, or electrolytic polishing is an electrochemical treatment performed on the metal surface to remove the impurities and microscopic imperfections. The process leaves a shiny, smooth, ultra-clean surface finish. A semiconductor EP tube is an electro polished tube manufactured and processed specifically for semiconductor fabrication facilities (fabs). After electro polishing, the tube is precision rinsed with 18 MΩ·cm ultra-pure water and dried with ultra high purity hot nitrogen inside a cleanroom, in compliance with SEMI F19 (Specification for the Surface Condition of the Wetted Surfaces of Stainless Steel Components). This semiconductor-grade treatment minimizes surface particles, metallic contamination and moisture adsorption, which is critical because even trace contamination on the inner wall of a gas or chemical delivery line can cause wafer defects and yield loss in advanced semiconductor processes. Why Semiconductor-Grade Processing Matters

Semiconductor manufacturing demands the highest level of surface purity. The semiconductor-grade treatment of our EP tubes provides:
✓  SEMI F19 compliant inner surface for ultra high purity (UHP) gas and chemical delivery
✓  Extremely low particle generation and outgassing from the electro polished bore
✓  Minimal metallic ion contamination (Cr-enriched passive layer after EP)
✓  18 MΩ·cm ultra-pure water rinsing removes ionic residues left by the EP process
✓  Reduced moisture adsorption for faster system purge-down and stable process gas purity
✓  Protects wafer yield by preventing contamination-related defects

Application

Semiconductor EP tubes are used wherever ultra-high purity fluid delivery directly affects wafer quality and device yield:
Semiconductor Industry High Purity Pipeline
Ultra High Purity (UHP) Gas Supply Lines
Specialty & Electronic Gas Delivery Systems
UPW (Ultra-Pure Water) Distribution in Fabs
Photovoltaic (Solar Cell) Manufacturing
LED & Flat Panel Display Production
Laboratory Gas Pipeline
Precision Instruments

Product Detail

Parameter	Value
Product Name	Semiconductor Electro Polishing Tube (Semiconductor EP Tube)
Material	TP316L (Ni ≥ 12%）
Outside Diameter	1/4" ~ 1" (6.35mm ~ 25.4mm)
Wall Thickness	0.035" ~ 0.083" (0.89mm ~ 2.11mm)
EP Lines	10
Daily Output	2,000 m
Inner Roughness	Ra ≤ 0.2µm
Outer Roughness	Ra ≤ 0.6µm

Material Grade

Grade	UNS	ASTM	EN
304L	S30403	304L	1.4307
316L	S31603	316L	1.4404
2205	S31803	S31803	1.4462
Hastelloy C-22	N06022	N06022	2.4602

* TP316L (Ni ≥ 12%) is the primary material for EP tubes.

Production Standard

Standard	Description
ASTM A269	Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubing for General Service
ASTM A270	Seamless and Welded Austenitic Stainless Steel Sanitary Tubing
ASTM B912	Standard Specification for Passivation of Stainless Steels Using Electropolishing

Process

Surface Preparation (Acid Cleaning) → Electro Polishing → Surface Passivation → Pure Water Treatment → Hot Nitrogen Drying → Clean Room Packaging
EP tube is derived from BA (bright annealing) pipe through electrochemical polishing, following ASTM B912 standard. For semiconductor service, the tubes are additionally rinsed with 18 MΩ·cm ultra-pure water and dried with ultra high purity hot nitrogen in a cleanroom, meeting SEMI F19 surface requirements.

Dimension Tolerance

Outside Diameter (OD)	Tolerance OD (mm)	Tolerance WT (%)
1/4" ~ 1"	±0.1	±10

Nominal Length: 6 meters / each, or customized.
If higher outside diameter tolerance is required, welcome to contact us.

Roughness

EP Roughness:
✓  Inner: Ra ≤ 0.2 µm
✓  Outer: Ra ≤ 0.6 µm
Lower roughness (e.g. Ra ≤ 0.13 µm inner) is available upon request.

Specification / Size Sheet

Standard length is 6 meters. Custom lengths are available upon request.

Outside Diameter (OD)		Wall Thickness (WT)		Unit Weight
Inch	mm	Inch	mm	kg/m
1/4	6.35	0.035	0.89	0.12
		0.049	1.24	0.16
3/8	9.53	0.035	0.89	0.19
		0.049	1.24	0.26
		0.065	1.65	0.33
1/2	12.7	0.035	0.89	0.26
		0.049	1.24	0.36
		0.065	1.65	0.46
3/4	19.05	0.049	1.24	0.55
		0.065	1.65	0.72
		0.083	2.11	0.90
		0.095	2.41	1.01
		0.105	2.67	1.10
1	25.4	0.065	1.65	0.98
		0.083	2.11	1.23

Final Inspection

Surface Quality
OD & WT, Length, Straightness, inner & outer surface roughness and endoscopy.
Chemical Composition
Spectrum analysis.
Mechanical Test
Tensile, Yield, Elongation (%), Hardness (HRB)
NDT (Non-Destructive Testing)
ET (Eddy Current testing).
PMI (Positive Material Identification)
Direct-reading spectrometer.
Marking and Color Coding
Marking and color coding available if required.
Optional Tests (Upon Customer Request)
According to customer requirements, the following additional tests can be performed on the sample(s):
✓  Chromium-iron ratio (Cr/Fe) and chromium oxide / iron oxide ratio
✓  Surface adsorption contamination
✓  Oxide layer thickness
✓  Surface defects
✓  Surface contamination
✓  Surface roughness
✓  Pitting temperature (CPT) test

Packing

EP tubing is ultrasonically cleaned then purged and dried with ultra high purity hot nitrogen before packing in the cleanroom. Each tube is end capped and bagged in double polyethylene bags to ensure the product's cleanliness. Finally the tubes are placed in wooden boxes for maximum protection during shipment.
1. Ultrasonic Cleaning — Tubes are ultrasonically cleaned to remove any residual particles.
2. Nitrogen Purge & Dry — Purged and dried with ultra high purity hot nitrogen.
3. Cleanroom Packaging — End capped, double-bagged in polyethylene, placed in wooden boxes.