ASTM A270 Sanitary Stainless Steel Tube dimensions

What Is ASTM A270 Sanitary Tubing?

ASTM A270 is the standard specification for seamless and welded austenitic stainless steel sanitary tubing, designed for:Food and dairy systems,Pharmaceutical and biotech industries,Beverage and cosmetic processing,CIP/SIP pipelines,It emphasizes hygienic finish, cleanability, and dimensional precision, often accompanied by surface finishes such as mechanical polish or electropolish.

ASTM A270 Sanitary Stainless Steel Tube Size Chart

Below is a reference chart of common outside diameters (OD) and wall thicknesses for ASTM A270 tubes. All dimensions are in inches and millimeters.

Tube Size (OD)	OD (in)	OD (mm)	Wall Thickness (in)	Wall (mm)	Schedule Equivalent
1/2"	0.500	12.70	0.065	1.65	10S / 16 SWG
3/4"	0.750	19.05	0.065	1.65	10S / 16 SWG
1"	1.000	25.40	0.065 / 0.083	1.65 / 2.11	10S / 14 SWG
1-1/2"	1.500	38.10	0.065 / 0.083	1.65 / 2.11	10S / 14 SWG
2"	2.000	50.80	0.065 / 0.109	1.65 / 2.77	10S / 12 SWG
2-1/2"	2.500	63.50	0.083 / 0.120	2.11 / 3.05	14 SWG / 11 SWG
3"	3.000	76.20	0.083 / 0.120	2.11 / 3.05	14 SWG / 11 SWG
4"	4.000	101.60	0.083 / 0.120	2.11 / 3.05	14 SWG / 11 SWG
6"	6.000	152.40	0.109 / 0.134	2.77 / 3.40	10S / 10 SWG

SWG = Standard Wire Gauge; 1.65 mm = ~16 SWG; 2.11 mm = ~14 SWG

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Tolerances for ASTM A270 Sanitary Tubing

Parameter	Tolerance
Outside Diameter (OD)	± 0.005 in (± 0.13 mm)
Wall Thickness	± 10%
Length (standard)	20 ft (6.1 m) random or cut to length

Surface Finish Options (Sanitary Grade)

Surface Finish	Roughness (Ra μin / μm)	Method
SF1	≤ 32 μin (0.8 μm)	Mechanical polish
SF4	≤ 15 μin (0.4 μm)	Electropolished
SF5/SF6	≤ 20 μin or better	Polished + passivated / cleaned

Common Materials Used for A270 Tubes

Material Grade	UNS No.	Description
316L	S31603	Excellent corrosion resistance (preferred)
304	S30400	General-purpose stainless
304L	S30403	Better weldability