- International Standard
- Material Grades
- Outer Diameter
- Wall Thickness
- Surface
- Tube Type
- MTC
- Certificate
- ASTM A270, EN10357, DIN11850, AS1528.1, ISO2037
- AISI 304/304L/316/316L
- 1/4″ - 12"
- 0.035″ - 0.12″
- Grit 180, 240, 320
- Welded , Seamless
- EN10204 3.1
- ISO 9001:2015 , PED 2014/68/EU , AD 2000-WO
- 6.35mm - 304.8mm
- 0.89mm - 3.05mm
- ≤20Ra (0.5 μm) ID , ≤30Ra (0.8 μm) OD
Food-grade stainless steel tubing is used where the process fluid and the cleaning method require a suitable, cleanable product-contact line. This page focuses on food and beverage production: specify the product medium, cleaning chemicals, temperature, grade, outside diameter, wall thickness, internal finish, and connection method before selecting a tube.
Grades such as 304/304L and 316/316L are selected against the actual corrosion and fabrication conditions; a material grade alone does not establish food-contact suitability or certify an installed system. For a standard-specific purchase, review ASTM A270 sanitary tubing, EN 10357 tubing, or DIN 11850 tubing.
For milk-specific transfer and processing requirements, see stainless steel dairy tubing. For system-level cleanability and connection considerations across hygienic processes, see hygienic process tubing.
For brewery lines such as wort transfer, fermentation and beer transfer, the selected tube and connections must suit the process fluid, temperature, cleaning regime and required finish. Confirm the dimensional standard and fitting interface before ordering; our sanitary tube standard compatibility guide provides a purchasing checklist.
For product-contact surfaces in food and beverage projects, compare Ra targets, mechanical polishing and electropolishing in our sanitary tube surface finish guide.
Food-contact selection: For brewery, dairy or acidic-food service, give the supplier the product composition, chloride exposure, cleaning chemicals, cleaning temperature and frequency. These conditions help assess whether 304/304L or 316/316L is suitable and what finish and weld-joint treatment to specify. A smooth tube surface alone does not establish regulatory approval for the complete assembled line.
ASTM A270 Size Reference for Food Processing Lines
The dimensions below help compare ASTM A270 tube sizes for food and beverage transfer lines. Select the actual grade, outside diameter, wall thickness, surface finish, and inspection documents against the process specification. For the standard and purchasing details, use the ASTM A270 sanitary tube page.
| DN | Tube OD | Wall Thickness | OD Tolerance | WT Tolerance | Length Tolerance | Weight |
|---|---|---|---|---|---|---|
| inch(mm) | inch(mm) | inch(mm) | inch(mm) | (kg/m) | ||
| 8 | 1/4" (6.35) | 0.035" (0.89) | +/-0.005" (0.13) | +/-10.0% | +1/8" (3.18) -0 | 0.124 |
| 15 | 1/2" (12.7) | 0.065" (1.65) / 0.049"(1.25) | +/-0.005" (0.13) | +/-10.0% | +1/8" (3.18) -0 | 0.454 |
| 20 | 3/4" (19.1) | 0.065" (1.65) / 0.049"(1.25) | +/-0.005" (0.13) | +/-10.0% | +1/8" (3.18) -0 | 0.717 |
| 25 | 1" (25.4) | 0.065" (1.65) / 0.049"(1.25) | +/-0.005" (0.13) | +/-10.0% | +1/8" (3.18) -0 | 0.976 |
| 40 | 1-1/2" (38.1) | 0.065" (1.65) / 0.049"(1.25) | +/-0.008" (0.20) | +/-10.0% | +1/8" (3.18) -0 | 1.50 |
| 50 | 2" (50.8) | 0.065" (1.65) / 0.049"(1.25) | +/-0.008" (0.20) | +/-10.0% | +1/8" (3.18) -0 | 2.02 |
| 65 | 2-1/2" (63.5) | 0.065" (1.65) | +/-0.010" (0.25) | +/-10.0% | +1/8" (3.18) -0 | 2.54 |
| 80 | 3" (76.2) | 0.065" (1.65) | +/-0.010" (0.25) | +/-10.0% | +1/8" (3.18) -0 | 3.06 |
| 100 | 4" (101.6) | 0.083" (2.11) | +/-0.015" (0.38) | +/-10.0% | +1/8" (3.18) -0 | 5.23 |
| 150 | 6" (152.4) | 0.109" (2.77) | +/-0.030" (0.76) | +/-10.0% | +1/8" (3.18) -0 | 10.32 |
| 200 | 8" (203.2) | 0.109" (2.77) | +/-0.030" (0.76) | +/-10.0% | +1/8" (3.18) -0 | 13.86 |
| 250 | 10"(254) | 0.120"(3.05) | +/-0.040" (1.016) | +/-10.0% | +1/8" (3.18) -0 | - |
| 300 | 12"(304.8) | 0.120"(3.05) | +/-0.040" (1.016) | +/-10.0% | +1/8" (3.18) -0 | - |
DIN 11850 and EN 10357 Sizes for Food Processing
The wall thickness is relatively thin, making it suitable for low-pressure or normal-temperature applications (such as low-pressure conveying in the food and pharmaceutical industries).
Typical applications: Non-corrosive media or low-pressure scenarios
| Nominal Diameter | Tube OD | Tolerances, OD | Wall Thickness | Telerances, WT | Telerances, Length | Weight |
|---|---|---|---|---|---|---|
| mm | mm | mm | mm | Kg/m | ||
| DN10 | 12 | ±0.12 | 1.0 | ±10% | ＋3.0 | 0.27 |
| DN15 | 18 | ±0.12 | 1.0 | ±10% | ＋3.0 | 0.42 |
| DN20 | 22 | ±0.12 | 1.0 | ±10% | ＋3.0 | 0.51 |
| DN25 | 28 | ±0.12 | 1.0 | ±10% | ＋3.0 | 0.66 |
| DN32 | 34 | ±0.12 | 1.0 | ±10% | ＋3.0 | 0.82 |
| DN40 | 40 | ±0.12 | 1.0 | ±10% | ＋3.0 | 0.97 |
| DN50 | 52 | ±0.2 | 1.0 | ±10% | ＋3.0 | 1.27 |
Medium wall thickness, combining strength and lightweight, suitable for medium pressure or general industrial applications.
Typical applications: Chemical industry, water treatment and other conventional working conditions.
| Nominal Diameter | Tube OD | Tolerances, OD | Wall Thickness | Tolerances, WT | Tolerances, Length | Length |
|---|---|---|---|---|---|---|
| mm | mm | mm | mm | (m) | ||
| DN10 | 13 | ±0.3 | 1.5 | ±10% | ＋3.00 | 0.43 |
| DN15 | 19 | ±0.3 | 1.5 | ±10% | ＋3.00 | 0.66 |
| DN20 | 23 | ±0.3 | 1.5 | ±10% | ＋3.00 | 0.81 |
| DN25 | 29 | ±0.3 | 1.5 | ±10% | ＋3.00 | 1.03 |
| DN32 | 35 | ±0.3 | 1.5 | ±10% | ＋3.00 | 1.26 |
| DN40 | 41 | ±0.3 | 1.5 | ±10% | ＋3.00 | 1.50 |
| DN50 | 53 | ±0.3 | 1.5 | ±10% | ＋3.00 | 1.944 |
| DN65 | 70 | ±0.3 | 2.0 | ±10% | ＋3.00 | 3.43 |
| DN80 | 85 | ±0.3 | 2.0 | ±10% | ＋3.00 | 4.16 |
| DN100 | 104 | ±0.3 | 2.0 | ±10% | ＋3.00 | 5.03 |
| DN125 | 129 | ±0.4 | 2.0 | ±10% | ＋10.00 | 6.36 |
| DN150 | 154 | ±0.4 | 2.0 | ±10% | ＋10.00 | 7.612 |
| DN200 | 204 | ±0.4 | 2.0 | ±10% | ＋10.00 | 10.116 |
| DN250 | 254 | ±0.4 | 2.0 | ±10% | ＋20.00 | 12.555 |
| DN300 | 304 | ±0.4 | 2.0 | ±10% | ＋20.00 | 15.045 |
The wall thickness is relatively thick, with a higher pressure-bearing capacity, making it suitable for high-pressure, high-temperature or highly corrosive media.
Typical applications: High-pressure steam, strong acids, strong alkalis and other harsh environments.
| Nominal Diameter | Tube OD | Tolerances, OD | Wall Thickness | Tolerances, WT | Tolerances, Length | Weight |
|---|---|---|---|---|---|---|
| mm | mm | mm | mm | Kg/m | ||
| 10 | 14 | ±0.3 | 2.0 | ±10% | +3.00 | 0.60 |
| 15 | 20 | ±0.3 | 2.0 | ±10% | +3.00 | 0.90 |
| 20 | 24 | ±0.3 | 2.0 | ±10% | +3.00 | 1.10 |
| 25 | 30 | ±0.3 | 2.0 | ±10% | +3.00 | 1.40 |
| 32 | 36 | ±0.3 | 2.0 | ±10% | +3.00 | 1.70 |
| 40 | 42 | ±0.3 | 2.0 | ±10% | +3.00 | 2.00 |
| 50 | 54 | ±0.3 | 2.0 | ±10% | +3.00 | 2.60 |
Finish Specifications
The standard mandates that the interior surface must be smooth, non-toxic, non-absorbent, and corrosion-resistant. This is primarily achieved through a mechanical polishing and electropolishing process. The result is an ultra-smooth finish that minimizes the ability for microbes and product particles to adhere, and it allows for effective cleaning and sterilization.
The most common and accepted finish is defined by a maximum Ra (Roughness Average) value. A typical Ra specification for ASTM A270 tubing is ≤ 0.38 µm (15 microinches) or better, often referred to as a “sanitary finish” or “micro-finish.” Some applications, like high-purity pharmaceutical or biotech processes, may require an even smoother finish of ≤ 0.25 µm (10 microinches).
This smooth surface is created by first mechanically abrading the tube with progressively finer abrasives to remove imperfections and weld beads. This is often followed by electropolishing, an electrochemical process that removes a thin layer of surface material. Electropolishing further smooths the surface, removes embedded contaminants, and enhances the natural passive oxide layer, which significantly improves corrosion resistance.
The primary purpose of this meticulously controlled surface is to prevent contamination, facilitate easy and effective cleaning-in-place (CIP) and sterilization-in-place (SIP) procedures, and provide superior corrosion resistance against aggressive cleaning chemicals and process fluids.
| Process | RA Micro Inch | RA Micron | ISO Designation |
|---|---|---|---|
| 150 grit | 30-35 | 0.75-0.875 | N6 |
| 150 grit + Electropolish | 12-20 | 0.3-.05 | |
| 180 grit | 20-25 | 0.5-.0625 | |
| 180 grit + Electropolish | 10-16 | 0.25-0.4 | |
| 240 grit | 15-20 | 0.375-0.5 | N5 |
| 240 grit + Electropolish | 8-12 | 0.2-0.3 | |
| 320 grit | 8-12 | 0.2-0.3 | N4 |
| 320 grit + Electropolish | 6-12 | 0.15-0.3 |
Chemical Composition of Stainless Steel Tube
| TUBE GRADES | UNS | Cr | Ni | Mo | C | P | S | Mn | Si |
|---|---|---|---|---|---|---|---|---|---|
| TP304 | S30400 | 18.0-20.0 | 8.0-11.0 | – | 0.08 | 0.045 | 0.03 | 2 | 1 |
| TP304L | S30403 | 18.0-20.0 | 8.0-13.0 | – | 0.035 | 0.045 | 0.03 | 2 | 1 |
| TP316 | S3160 | 16.0-18.0 | 11.0-14.0 | 2.0-3.0 | 0.08 | 0.045 | 0.03 | 2 | 1 |
| TP316L | S31603 | 16.0-18.0 | 10.0-14.0 | 2.0-3.0 | 0.035 | 0.045 | 0.03 | 2 | 1 |
Tensile Properties of Stainless Steel Tube
| Material | Heat Treatment | Yield Strength Ksi (MPa), Min. | Tensile Strength Ksi (MPa), Min. | Temperure Min. ℉(℃) | Elongation %, Min |
| ASME SA270 304 | Solution | 30(205) | 75(515) | 1900 (1040) | 35 |
| ASME SA270 304L | Solution | 25(170) | 70(485) | 1900 (1040) | 35 |
| ASME SA270 316 | Solution | 30(205) | 75(515) | 1900(1040) | 35 |
| ASME SA270 316L | Solution | 25(170) | 70(485) | 1900(1040) | 35 |
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Sanitary Fittings in Process Piping (Food, Pharma, Dairy, etc.)
In industrial contexts, Sanitary Fittings (or Hygienic Fittings) refer to the specialized components used to connect pipes in systems where purity and cleanliness are critical. They are designed to prevent bacterial growth, allow for complete cleaning, and ensure product integrity.
Key Idea: These are the connectors and pipes themselves, used to build a system for processing sensitive products.
Key Characteristics:
Smooth, Polished Surfaces: Internally, they have a very smooth finish (often measured in Ra micro-inches) to prevent bacteria from clinging and to allow for easy cleaning.
No Crevices or Dead Spaces: They are designed to be flush with the pipe, creating a seamless flow path so that product or cleaning fluids don’t get trapped.
Easy to Disassemble and Clean (CIP/SIP): They are designed for frequent cleaning, often using methods like Clean-in-Place (CIP) or Sterilize-in-Place (SIP).
Material: Almost exclusively made from 304 or 316L Stainless Steel for its corrosion resistance and non-reactivity.
Common Types of Sanitary Fittings:
Clamp Fittings (Tri-Clamp): The most common type, using a three-piece clamp to seal a gasket between two ferrules.
Butt Weld Fittings: Permanently welded to create a perfectly smooth, crevice-free joint. Used where disassembly isn’t needed.
Bevel Seat Fittings: An older style, similar to clamp fittings but with a different gasket and connection system.
DIN/SMS Fittings: Standards more common in Europe, using a threaded nut to compress a gasket.
Common Components:
Elbows (90°, 45°)
Tees
Reducers
Caps
Ferrule (the stub end that gets connected)