ASTM A270 SanitaryTubing.pdf

What is the ASTM A270 standard?

ASTM A270 is a standard specification for sanitary stainless steel tubing, suitable for industries with extremely high hygiene requirements, such as food, dairy, and pharmaceutical. ASTM A270 sanitary stainless steel tubing typically refers to small-diameter tubing, generally 1/2 1/2 inches, with wall thicknesses of 0.049 inches (1.24 mm) to 0.15 inches (3.81 mm), suitable for clean environments and featuring a smooth, defect-free surface.

 

What is the chemical composition of ASTM A270?

ASTM A270 specifies chemical compositions for sanitary stainless steel tubing, with the most common being grades TP304 and TP316. TP304 is an 18/8 stainless steel with 18-20% chromium and 8-11% nickel, while TP316 contains molybdenum for enhanced corrosion resistance.

 

Mechanical Properties

 

What is the surface finish of ASTM A270?

Mill Finish- A finish without additional polishing oroperations intended to smooth the surface.
Mechanically Polished Surface Finish-The purchaser may specify one of the following finish numbers for a mechanically polished surface:
Finish No. 80-A ground finish produced by polishing a tube with an abrasive media impregnated with No. 80 grit.
Finish No. 120-No. 120 grit.
Finish No. 180-No. 180 grit.
Finish No. 240-No. 240 grit.
Other mechanically polished finishes may beagreed upon between the purchaser and manufacturer

 

What is the tolerance of ASTM A270?
ASTM A270 stipulates that the wall thickness at any point cannot exceed 12.5% ​​of the required wall thickness.

 

What size is ASTM A270?

ASTM A270 sanitary stainless pipe usually refers to the small pipe diameters, normally from 1/2" to 2 1/2", thickness from 0.049 in (1.24mm) to 0.15 in (3.81mm). The maximum outer diameter of ASTM A270 tubing is 12 inches (304.8 mm).

 

ASTM A270 pipe dimensions

ASTM A270 pipe dimensions vary depending on grade and manufacturing method, but typically range from 1/2 inch to 12 inches (12.7 mm to 304.8 mm) in outer diameter and 0.049 inches to 0.15 inches (1.24 mm to 3.81 mm) in wall thickness. Lengths are usually sold in 6-meter units, but can also be cut to customer specifications. Wall thickness tolerances are typically ±10%.

 

What is the difference between ASTM A269 and A270?

The main difference is that ASTM A269 tubing is for general service, while ASTM A270 is for sanitary purposes, requiring a much higher standard of surface finish and cleanability. A270 mandates specific internal and external surface finish requirements, often including polishing and electropolishing, and requires an internal weld bead removal for certain applications, whereas A269 accepts a "workmanlike finish" and is not required to meet sanitary cleanliness standards.