XM-28 (UNS S24100) Stainless Steel Reinforcement Bars
When infrastructure demands uncompromising corrosion resistance paired with high strength, the reinforcement material must perform without compromise. FUSHUN METAL (Hunan Fushun Metal Co., Ltd.), a global manufacturer and exporter of specialty steels, produces XM-28 (UNS S24100) deformed and plain stainless steel reinforcement bars in full conformance with ASTM A955/A955M — the standard specification for deformed and plain stainless steel bars for concrete reinforcement. With manufacturing disciplines aligned to ASTM, EN, DIN, and JIS standards, our XM-28 bars are engineered to deliver reliable, long-term performance in the most aggressive environments.
Request a Quote for your next project requiring XM-28 reinforcement bars.
Chemical Composition
The corrosion resistance and elevated mechanical properties of XM-28 are achieved through precise control of its chemical composition. FUSHUN METAL performs a heat analysis from test samples taken during the pouring or casting of every heat. The chemistry conforms strictly to the requirements of ASTM A955/A955M Table 2 for UNS S24100.
| Element | Composition % |
|---|---|
| Carbon (C) | 0.15 max. |
| Manganese (Mn) | 11.00 – 14.00 |
| Phosphorus (P) | 0.060 max. |
| Sulfur (S) | 0.030 max. |
| Silicon (Si) | 1.00 max. |
| Chromium (Cr) | 16.50 – 19.00 |
| Nickel (Ni) | 0.50 – 2.50 |
| Nitrogen (N) | 0.20 – 0.45 |
This nitrogen-strengthened austenitic grade is listed among the typical alloys that have found the most use in North America according to ASTM A955/A955M. Its balanced composition provides excellent resistance to chloride-induced corrosion, high yield strength, and good ductility. The lower nickel range compared to similar grades makes XM-28 a cost-effective choice among nickel-containing stainless alloys for concrete reinforcement. When requested, product analysis can be conducted and will conform to the tolerances specified in ASTM A484/A484M.
Heat Treatment Condition
The mechanical properties of XM-28 reinforcement bars are directly determined by the heat treatment condition at the time of manufacture. FUSHUN METAL supplies bars in the following conditions, as defined in ASTM A276 and referenced by ASTM A955/A955M:
- Annealed (A)
- Hot Rolled (HR)
- Strain Hardened (B)
The selection of heat treatment condition is a critical ordering parameter, as it fundamentally influences the strength level and ductility. Any subsequent heat treatment applied after delivery may alter the as-supplied properties. The standard cautions that no re-treatment should be performed without retesting to the full requirements of ASTM A955/A955M.
Size
FUSHUN METAL manufactures XM-28 deformed bars across the complete range of standard bar designation numbers listed in ASTM A955/A955M Table 1. The nominal dimensions of a deformed bar correspond to a plain round bar of equal weight per foot.
| Bar Designation No. | Nominal Diameter, in. [mm] | Nominal Weight, lb/ft [kg/m] (300 Series) |
|---|---|---|
| 3 [10] | 0.375 [9.5] | 0.378 [0.562] |
| 4 [13] | 0.500 [12.7] | 0.686 [1.021] |
| 5 [16] | 0.625 [15.9] | 1.058 [1.575] |
| 6 [19] | 0.750 [19.1] | 1.511 [2.248] |
| 7 [22] | 0.875 [22.2] | 2.059 [3.064] |
| 8 [25] | 1.000 [25.4] | 2.713 [4.037] |
| 9 [29] | 1.128 [28.7] | 3.341 [5.106] |
| 10 [32] | 1.270 [32.3] | 4.358 [6.484] |
| 11 [36] | 1.410 [35.8] | 5.352 [7.964] |
| 14 [43] | 1.693 [43.0] | 7.72 [11.49] |
| 18 [57] | 2.257 [57.3] | 13.72 [20.43] |
Plain rounds in diameters up to and including 2 in. [50.8 mm] are also available for dowels, spirals, and structural supports. Bars are furnished in standard or custom-cut lengths to meet project specifications.
Grade (Strength Level)
XM-28 bars are produced in three minimum yield strength grades, as prescribed in ASTM A955/A955M. Tensile properties are verified on full-section specimens, with unit stress based on the nominal cross-sectional area.
| Grade | Tensile Strength, min | Yield Strength, min |
|---|---|---|
| Grade 40 [300] | 70,000 psi [500 MPa] | 40,000 psi [300 MPa] |
| Grade 60 [420] | 90,000 psi [620 MPa] | 60,000 psi [420 MPa] |
| Grade 75 [520] | 100,000 psi [690 MPa] | 75,000 psi [520 MPa] |
Yield strength is determined at 0.35% strain under the autographic diagram method or with an extensometer in accordance with ASTM A370. Elongation requirements vary by bar size and grade, as detailed in ASTM A955/A955M Table 3. The target grade must be specified at the time of order.
Packaging
FUSHUN METAL ensures that all XM-28 reinforcement bars are properly separated and tagged with the manufacturer's heat or test identification number at the time of mill shipment. Each bundle is tagged with the following information:
- Stainless steel alloy (XM-28 / UNS S24100)
- Heat treatment condition
- Grade (minimum strength level)
- Supplementary requirement status (S1, if applicable)
When packaging procedures are specified in the purchase order, they conform to ASTM A700. For U.S. Government procurement, packaging complies with MIL-STD-163, and marking for shipment meets Fed. Std. No. 123 for civil agencies or MIL-STD-129 for military agencies. Every deformed bar is legibly marked on one side with the manufacturer's mill designation and the bar size designation. Plain rounds do not require rolled-on symbols; all required information is provided on the bundle tag.
Inspection
The purchaser's inspector is granted free entry at all times during contract execution to all areas of the manufacturer's works related to the production of the ordered material. FUSHUN METAL provides access to all reasonable facilities to verify that material conforms to ASTM A955/A955M. All inspection and testing are performed at the manufacturing site prior to shipment and are carried out in a manner that does not unnecessarily interfere with operations.
Test
For each heat, bar size, and heat treatment condition, FUSHUN METAL performs the following tests as a minimum:
- One tension test — conducted on the full bar section, evaluated against the specified grade requirements.
- One bend test — performed on the full bar section, with the specimen bent around a pin to the degree and pin diameter prescribed in ASTM A955/A955M Table 4, without cracking on the outside radius.
- One set of dimensional property tests — including bar weight and measurements of deformation spacing, average height, and gap, all verified against the limits in ASTM A955/A955M Table 1.
Deformation spacing is averaged from a minimum of ten spaces; average height is determined from three measurements taken on each of at least two typical deformations. The measured weight of any deformed bar shall be at least 94% of the value specified in Table 1. If a test specimen fails due to mechanical reasons, a replacement specimen is permitted. When a failure meets the retest provisions, two additional random specimens are tested and must meet all requirements. When Supplementary Requirement S1 is invoked for controlled magnetic permeability, testing is conducted in accordance with ASTM A342, with limits agreed between manufacturer and purchaser.
Report
FUSHUN METAL issues a Material Test Report, Certificate of Inspection, or equivalent document for every order. Reports are generated on a per-heat or per-lot basis and contain:
- Stainless steel type and designation (XM-28 / UNS S24100)
- Chemical composition (heat analysis, and product analysis if performed)
- Heat treatment condition
- Bar size
- Tensile properties (tensile strength, yield strength, elongation)
- Bend test results
- Corrosion test results (when specified)
- Magnetic permeability results (when Supplementary Requirement S1 is invoked)
Documents transmitted via electronic data interchange (EDI) are as valid as printed versions. The EDI-transmitted document meets all requirements of ASTM A955/A955M, and the organization submitting the transmission is responsible for its content.
Frequently Asked Questions
How does XM-28 (UNS S24100) differ from XM-29 and why choose it?
Both are nitrogen-strengthened austenitic grades. XM-28 has a higher carbon maximum (0.15% vs. 0.08%) and a lower nickel range (0.50–2.50% vs. 2.25–3.75%), making it often more economical while maintaining high strength and excellent chloride-corrosion resistance. Selection depends on the required cost-strength-corrosion balance for your project.
In what heat treatment condition should I order XM-28 bars?
Annealed provides highest ductility; Hot Rolled and Strain Hardened yield progressively higher strength. Match the condition with your target grade (40, 60, or 75) based on structural design requirements per ASTM A955. Our technical team can advise on the optimal combination.
What packaging and traceability measures does FUSHUN METAL employ for XM-28?
Each bundle is tagged with alloy, heat treatment, grade, and heat identification. Deformed bars carry mill markings and size designation. A Material Test Report with full chemical and mechanical data accompanies every shipment, providing complete melt-to-site traceability.
Can I order XM-28 bars with controlled magnetic permeability for specialized environments?
Yes. Specify Supplementary Requirement S1 in your purchase order. FUSHUN METAL manufactures and tests the bars per ASTM A342 with mutually agreed permeability limits, ensuring compliance for MRI facilities, sensitive electronic installations, and other non-magnetic applications.
Get XM-28 Reinforcement Bars for Your Project
FUSHUN METAL (Hunan Fushun Metal Co., Ltd.) is a trusted global manufacturer of alloy steel, nickel-based alloys, stainless steel, and tool steel. Our products serve demanding industries worldwide, backed by full compliance with international standards including ASTM, EN, DIN, and JIS. For inquiries and technical support on XM-28 (UNS S24100) reinforcement bars, Request a Quote or visit our website for more information.
