Chemical Composition Element Specified / Typical Range (wt. %) C ≤0.08 Mn ≤2.00 Si ≤1.00 P ≤0.045 S ≤0.030 Cr 17.0–20.0 Ni 9.0–13.0 Mo — N ≤0.10 Nb+Ta ≥10×C; ≤1.00 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 17.0–20.0 Ni 9.0–13.0 Mo — N ≤0.10 Nb+Ta ≥10×C; ≤1.00 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

347 Stainless Steel Tees

Grade: 347/347H

Types:

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

Standards:

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

347 is a niobium-stabilized austenitic stainless steel developed for improved resistance to intergranular corrosion after welding and during elevated-temperature service. It has a chemistry broadly related to 304, with niobium added for stabilization. 347 fittings are commonly used in refinery, petrochemical, thermal and chemical-process piping where welded joints experience elevated temperatures or repeated thermal cycles.

Chemical Composition

Element	Specified / Typical Range (wt. %)
C	≤0.08
Mn	≤2.00
Si	≤1.00
P	≤0.045
S	≤0.030
Cr	17.0–20.0
Ni	9.0–13.0
Mo	—
N	≤0.10
Nb+Ta	≥10×C; ≤1.00
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	17.0–20.0
Ni	9.0–13.0
Mo	—
N	≤0.10
Nb+Ta	≥10×C; ≤1.00
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