Chemical Composition Element Specified / Typical Range (wt. %) C ≤0.08 Mn ≤2.00 Si ≤1.00 P ≤0.045 S ≤0.030 Cr 17.0–19.0 Ni 9.0–12.0 Mo — N ≤0.10 Ti ≥5×C; ≤0.70 Fe Balance

Mechanical Properties Property Minimum / Requirement Tensile Strength, min. 515 MPa Yield Strength, 0.2%, min. 205 MPa Elongation, min. 30% Hardness As required by the applicable fitting specification

Chemical and petrochemical plants Oil and gas gathering and processing Process branch piping Water treatment and utility systems Food, pharmaceutical and sanitary piping Offshore and marine systems

Chemical Composition Element Specified / Typical Range (wt. %) C ≤0.08 Mn ≤2.00 Si ≤1.00 P ≤0.045 S ≤0.030 Cr 17.0–19.0 Ni 9.0–12.0 Mo — N ≤0.10 Ti ≥5×C; ≤0.70 Fe Balance

Mechanical Properties Property Minimum / Requirement Tensile Strength, min. 515 MPa Yield Strength, 0.2%, min. 205 MPa Elongation, min. 30% Hardness As required by the applicable fitting specification

Chemical and petrochemical plants Oil and gas gathering and processing Process branch piping Water treatment and utility systems Food, pharmaceutical and sanitary piping Offshore and marine systems

321/321H Stainless Steel Tees

Grade: 321

Types:

Equal Tee, Straight Tee, Reducing Tee, Seamless Tee, Welded Tee, Butt-Welding Tee.

Standards:

ASTM B16.9, EN10253-4, JIS B2312/2313

321 is a titanium-stabilized austenitic stainless steel based on the 304 family. Titanium reduces the tendency for chromium carbide precipitation during elevated-temperature exposure, making the grade useful for welded fittings subjected to heat and thermal cycling. It provides good general corrosion resistance together with good high-temperature stability and is commonly specified for thermal process piping, heat exchangers and petrochemical equipment.

Chemical Composition

Element	Specified / Typical Range (wt. %)
C	≤0.08
Mn	≤2.00
Si	≤1.00
P	≤0.045
S	≤0.030
Cr	17.0–19.0
Ni	9.0–12.0
Mo	—
N	≤0.10
Ti	≥5×C; ≤0.70
Fe	Balance

Mechanical Properties

Property	Minimum / Requirement
Tensile Strength, min.	515 MPa
Yield Strength, 0.2%, min.	205 MPa
Elongation, min.	30%
Hardness	As required by the applicable fitting specification

Chemical and petrochemical plants
Oil and gas gathering and processing
Process branch piping
Water treatment and utility systems
Food, pharmaceutical and sanitary piping
Offshore and marine systems

Introduction

Specification

Chemical Composition

Element	Specified / Typical Range (wt. %)
C	≤0.08
Mn	≤2.00
Si	≤1.00
P	≤0.045
S	≤0.030
Cr	17.0–19.0
Ni	9.0–12.0
Mo	—
N	≤0.10
Ti	≥5×C; ≤0.70
Fe	Balance

Mechanical

Mechanical Properties

Property	Minimum / Requirement
Tensile Strength, min.	515 MPa
Yield Strength, 0.2%, min.	205 MPa
Elongation, min.	30%
Hardness	As required by the applicable fitting specification