AP(Annealed & Pickled)Stainless Steel Pickled Tube

AP（Annealed & Pickled） Stainless Steel Pickled Tube refers to a type of stainless steel tubing that undergoes an annealing and pickled surface treatment process. During production, the stainless steel is heat treated through annealing to improve its mechanical properties, followed by acid pickling to remove oxide scale and surface impurities. This process helps achieve a clean and uniform surface condition.

Compared with untreated tubing, AP tubing offers stable corrosion resistance and a consistent surface quality suitable for industrial use. It is commonly considered a basic clean surface option before further processing such as BA tubing (bright annealed) or electropolishing, depending on application requirements.

AP（Annealed & Pickled） stainless steel tubes are widely used in general industrial piping systems, structural applications, and equipment manufacturing where reliable stainless steel performance is required without high-purity surface finishing.

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Material Grades:

TP316L, 304L, 310S, 317L, 321H, 347H, UNS S31803, S32205, S32750, etc. (other materials available upon request)

Size Range:

OD 6.00 mm ~ OD 114.30 mm

Product Description:

AP (Annealed & Pickled) Stainless Steel Tube is a stainless steel tube that has undergone solution annealing followed by acid pickling to remove surface oxides, scale, and contaminants formed during hot processing.

AP tubes are commonly used as a basic clean finish for industrial stainless steel piping before further processing or in applications where moderate surface cleanliness is required.

FAQs

What Is AP Stainless Steel Pickled Tube?

AP (Annealed & Pickled) stainless steel tube is a stainless steel tubing product that undergoes solution annealing followed by acid pickling. The annealing process improves mechanical properties, while pickling removes oxide scale, heat tint, and surface contaminants formed during manufacturing. The result is a clean, matte surface suitable for industrial applications.

What Does AP Mean In Stainless Steel Tubing?

AP stands for Annealed and Pickled.

The tube is first heat treated through annealing and then chemically pickled to remove oxidation and impurities. AP tubing is commonly regarded as the standard industrial finish for stainless steel tubing.

Why Is Stainless Steel Tubing Pickled?

Pickling removes:

Oxide scale

Heat tint

Surface contamination

Iron residues

This process restores the stainless steel surface and helps maintain corrosion resistance by allowing the chromium-rich passive layer to reform properly.

What Is The Difference Between AP And Electropolished (EP) Tubing?

EP tubing receives additional electrochemical polishing after manufacturing.

Compared with AP tubing, EP tubing provides:

Lower surface roughness

Higher cleanliness

Improved passivation

Better contamination control

EP tubing is commonly used in semiconductor and pharmaceutical systems, while AP tubing is suitable for general industrial service.

Can AP Tubing Be Used For Food Or Pharmaceutical Applications?

AP tubing may be used in certain non-critical process systems.

However, hygienic and high-purity applications typically require BA or EP tubing because of their smoother surfaces and enhanced cleanliness.