ASTM A276 AISI 321H Stainless Steel Round Rod

Are you sourcing machined stainless steel components-such as furnace internals, heat exchanger tubesheets, expansion joints, or process equipment-that must retain sufficient mechanical strength during long-term service at temperatures above 550°C? If conventional 304 or 316 stainless steel bars lose their load-bearing capacity at your operating temperatures, and standard 321 stainless steel fails to meet your requirements for creep resistance and rupture strength under long-term high-temperature conditions, then ASTM A276 AISI 321H (UNS S32109) stainless steel round bars are the ideal solution.

The ASTM A276 standard covers hot-finished and cold-finished stainless steel bars and shapes for general industrial use. AISI 321H is a high-carbon variant of the titanium-stabilized 18-10 austenitic stainless steel; its carbon content is controlled between 0.04% and 0.10%, with a titanium content at least four times the sum of its carbon and nitrogen content. In its annealed state, 321H stainless steel bars offer certified creep resistance and rupture strength within the 525°C to 816°C temperature range. Furthermore, the material maintains excellent resistance to intergranular corrosion, even after welding or following prolonged exposure to temperatures that typically trigger carbide precipitation.

Compared to standard-grade 321, 321H stainless steel bars offer approximately 38% higher allowable stress at 600°C, 50% higher at 700°C, and 47% higher at 815°C. This makes the material an excellent choice for components subjected to sustained loads at elevated temperatures. In an air environment, it exhibits good oxidation resistance during continuous operation at temperatures up to 870°C, and can withstand temperatures as high as 925°C under intermittent exposure conditions.

We supply AISI 321H stainless steel round bars in accordance with the ASTM A276 standard, available in various surface finishes, including hot-rolled (black bar), peeled/turned, and polished. Our size range covers diameters from 8 mm to 350 mm, with standard lengths of 3 to 6 meters; custom-cut lengths are also available upon request. Furthermore, we can process 321H bars into forged stepped shafts, discs, and ring blanks based on customer drawings.

SS 321H Cold-Drawn Black-Surface Bar

SS 321H Turned surface Bar

Each batch is supplied with a fully traceable EN 10204 3.1 Material Test Certificate (MTC). We can also facilitate third-party inspections by organizations such as SGS, BV, or TÜV to meet project tender requirements.

321H Equivalent Grades

Chemical Composition of ASTM A276 321H Stainless Steel

Mechanical Properties of 321H Stainless Steel Round Bar

Confirm the applicable mechanical requirements against the specified ASTM A276 edition, product size and delivery condition.

Available Sizes of 321H Stainless Steel Round Rod

SS 321H Round Rod Applications

High-temperature industrial equipment

Heat exchangers and furnace components

Chemical processing equipment

Petroleum and petrochemical machinery

Pressure vessel components

Exhaust systems and thermal processing equipment

SS 321H Round Rod Price per kg

In the Chinese market, the price of SS 321H round bars ranges from approximately 1,200 to 2,800 USD per metric ton (roughly 1.20 to 2.80 USD or more per kilogram). The exact price depends on the supplier, the quantity ordered, and the diameter of the round bars.

Request a Quote Now

Quality Inspection

Every production batch is subject to mandatory inspection in accordance with the ASTM A276 standard. This includes: spectrochemical analysis, room-temperature tensile testing, Brinell hardness testing, ultrasonic testing for internal quality and critical dimensions, and Positive Material Identification (PMI). For projects involving pressure vessels or furnace components, we also offer supplementary testing, such as high-temperature tensile verification, grain size evaluation, intergranular corrosion testing (per ASTM A262), and Charpy impact testing.

 

Ultrasonic Testing

Dimensional Inspection

Lead time and packaging:

Standard hot-rolled stock sizes ship within 8–14 working days; peeled, ground or custom-machined bars require 18–28 working days. Bars are protected with end caps, wrapped in anti-rust paper, bundled with steel strapping and packed on fumigated wooden pallets or in wooden crates for ocean shipment, marked with grade, heat number, diameter and ASTM A276 for full receiving traceability.

 

FAQ

Q: What is the key difference between 321 and 321H?
A: 321H has a controlled higher carbon range (0.04–0.10%) and coarser grain structure, delivering significantly higher creep and stress-rupture strength above 538°C. Both are titanium-stabilized and resist intergranular corrosion after welding. Below 500°C the mechanical difference is small; above 550°C 321H is the correct choice for sustained load service.

Q: Can 321H bar be used for threaded fasteners and bolting?
A: Yes, 321H round bar is commonly machined into high-temperature bolts, studs and nuts for furnace and pressure vessel assemblies, where elevated-temperature strength and resistance to stress relaxation are required.

Q: Is 321H suitable for chloride-containing hot process streams?
A: No. 321H contains no molybdenum and is not intended for chloride-bearing media. For hot chloride service, molybdenum-bearing grades such as 316H or super duplex alloys are the appropriate selection.

Hot Tags: astm a276 aisi 321h stainless steel round rod, China astm a276 aisi 321h stainless steel round rod manufacturers, suppliers, factory