ASTM A335 Gr. P9 Studded Fin Tubes are designed for high-temperature heat transfer applications in cracking furnaces, where excellent resistance to oxidation, creep, and thermal fatigue is essential. Manufactured from 9Cr-1Mo alloy steel seamless tubes, these studded fin tubes provide an enlarged external heat transfer surface while maintaining outstanding mechanical integrity under prolonged exposure to elevated temperatures.

The welded studs significantly improve heat absorption from high-temperature flue gases, making the tubes suitable for convection sections of ethylene cracking furnaces, petrochemical heaters, and other demanding thermal processing equipment. ASTM A335 Gr. P9 offers superior high-temperature performance compared with conventional carbon steel materials, ensuring longer service life and improved operational reliability.

Features

Manufactured from ASTM A335 Gr. P9 seamless alloy steel tubes
Excellent creep strength at elevated temperatures
Superior oxidation and scaling resistance
Enhanced heat transfer efficiency through welded studs
Suitable for continuous high-temperature operation
High structural stability under cyclic thermal loading
Available in customized stud dimensions and tube configurations
Manufactured according to ASME, ASTM, and customer specifications

Typical Applications

ASTM A335 Gr. P9 Studded Fin Tubes are widely used in high-temperature industrial heating equipment, including:

Ethylene Cracking Furnaces
Petrochemical Fired Heaters
Refinery Process Heaters
Convection Sections of Process Furnaces
Waste Heat Recovery Boilers
Process Gas Heating Systems
High-Temperature Heat Exchangers
Steam Reforming Furnaces
Hydrogen Production Units
Chemical Processing Plants

Dimensional Range

Parameter	Standard Range
Base Tube OD	25.4–168.3 mm (1"–6")
Base Tube Wall Thickness	2.77–12.70 mm
Tube Length	Up to 18,000 mm
Stud Diameter	6–20 mm
Stud Height	10–35 mm
Stud Pitch	8–30 mm
Stud Material	Carbon Steel, Alloy Steel, Stainless Steel (according to application)
Manufacturing Standard	ASTM A335 / ASME SA335 / Customer Drawings

Chemical Composition of ASTM A335 Gr. P9

Element	Content (%)
Carbon (C)	0.15 Max
Manganese (Mn)	0.30–0.60
Phosphorus (P)	0.025 Max
Sulfur (S)	0.025 Max
Silicon (Si)	0.25–1.00
Chromium (Cr)	8.00–10.00
Molybdenum (Mo)	0.90–1.10

Mechanical Properties of ASTM A335 Gr. P9

Property	Value
Tensile Strength	≥ 415 MPa
Yield Strength	≥ 205 MPa
Elongation	≥ 20%

Ratings & Review

Overall Rating

4.7

Based on 50 reviews for this supplier

Rating Snapshot

The following is the distribution of all ratings

5 stars

67%

4 stars

33%

3 stars

2 stars

1 stars

All Reviews

Kenneth Tan

Singapore Feb 25.2026

Helpful (3)

With our humidity and year-round high temps, corrosion resistance and heat transfer are always a concern. These tubes have been performing nicely.

Pieter

South Africa Dec 17.2025

Helpful (4)

With high firebox temps and some sour gas in the mix, regular carbon tubes don't last. These have been solid.

Rashid

United Arab Emirates Dec 10.2025

Helpful (2)

Good oxidation resistance, matches well with the T9. No scaling or thinning noticed.

Tags:

Studded Tube

Solid Fin Tube

Serrated Finned tube

Embedded G Fin Tube

Extruded Fin Tube

Wound Fin Tube

Low Fin Tube

Square Fin Tube

Longitudinal Finned Tube

Enhanced Heat Transfer Tube

Fin Tube Support

Return Bend

Heat Exchanger Tube

Stainless Steel Heat Exchanger Tube

Duplex Stainless Steel Heat Exchanger Tube

Super Duplex Stainless Steel Heat Exchanger Tube

Nickel Alloy Steel Heat Exchanger Tube

Copper Alloy Steel Heat Exchanger Tube

Titanium Alloy Steel Heat Exchanger Tube

Alloy Steel Heat Exchanger Tube

U Bend Heat Exchanger Tube

Carbon Steel Heat Exchanger Tubes

Boiler Tube

Nickel Alloy Steel Boiler Tube

Stainless Steel Boiler Tube

Duplex Stainless Steel Boiler Tube

Alloy Steel Boiler Tube

Carbon Steel Boiler Tube

Fired Heater Parts

Baffle Plate

Tubesheet

Studded Tube

Solid Fin Tube

Serrated Finned tube

Embedded G Fin Tube

Extruded Fin Tube

Wound Fin Tube

Low Fin Tube

Square Fin Tube

Longitudinal Finned Tube

Enhanced Heat Transfer Tube

Fin Tube Support

Return Bend

Heat Exchanger Tube

Stainless Steel Heat Exchanger Tube

Duplex Stainless Steel Heat Exchanger Tube

Super Duplex Stainless Steel Heat Exchanger Tube

Nickel Alloy Steel Heat Exchanger Tube

Copper Alloy Steel Heat Exchanger Tube

Titanium Alloy Steel Heat Exchanger Tube

Alloy Steel Heat Exchanger Tube

U Bend Heat Exchanger Tube

Carbon Steel Heat Exchanger Tubes

Boiler Tube

Nickel Alloy Steel Boiler Tube

Stainless Steel Boiler Tube

Duplex Stainless Steel Boiler Tube

Alloy Steel Boiler Tube

Carbon Steel Boiler Tube

Fired Heater Parts

Baffle Plate

Tubesheet

products details

Studded Tube

Solid Fin Tube

Serrated Finned tube

Embedded G Fin Tube

Extruded Fin Tube

Wound Fin Tube

Low Fin Tube

Square Fin Tube

Longitudinal Finned Tube

Enhanced Heat Transfer Tube

Fin Tube Support

Return Bend

Heat Exchanger Tube

Stainless Steel Heat Exchanger Tube

Duplex Stainless Steel Heat Exchanger Tube

Super Duplex Stainless Steel Heat Exchanger Tube

Nickel Alloy Steel Heat Exchanger Tube