Hastelloy C-276 and Alloy 22 Round Rod

Hastelloy C-276 (UNS N10276) and Alloy 22 (UNS N06022) are low-carbon nickel-chromium-molybdenum alloys supplied as round rod under ASME SB-574. The same specification also covers Alloy 59, C-22, C-2000, 686, and several other Ni-Cr-Mo and Ni-Mo-Cr grades, which makes it the standard reference for anyone consolidating a corrosion-resistant rod order. This page covers the grade range, the chemical and tensile requirements, and what to specify when you inquire.

What These Rods Are Used For

These alloys are chosen where wet-process corrosion is severe: scrubbing and absorption systems in hydrochloric, sulphuric and phosphoric acid plants, pulp and paper bleaching equipment, dye and pharmaceutical processing, and sour gas handling. The combination of high molybdenum and chromium with very low carbon content gives resistance to general corrosion, pitting and crevice attack, and intergranular attack in reducing acid environments.

Low carbon is the defining feature. Keeping carbon at or below 0.010 to 0.015 % minimises grain-boundary precipitation of carbides and preserves corrosion resistance in the as-delivered condition, so post-weld heat treatment is generally not required for corrosion reasons. This is the practical difference between C-276 and the older C alloy, which needed solution annealing after welding to restore intergranular resistance.

Grade Comparison

Note on C-22: it shares UNS N06022 with Alloy 22 because they are the same composition; the two designations reflect different product histories. If a purchase order calls out Alloy 22 for a rod, C-22 is the equivalent designation for the same UNS number, and both are supplied to SB-574.

Chemical Composition (ASME SB-574 Table 1)

Full composition limits for all ten grades covered by SB-574 (including N06035, N06044, N06058, N06200, N06210, N06455 and N10362) are listed in Table 1 of the specification.

Mechanical Properties and Size Range

SB-574 Table 3 ties tensile strength to the rod diameter D by grade and condition. The pattern is that smaller diameters must be stronger, reflecting the difficulty of achieving segregation control in large sections:

If the grade is not stated on the order, state the required tensile level and we will confirm which grade applies to your diameter. SB-574 Appendix X1 states that proper heat treatment during or subsequent to fabrication is necessary for optimum performance and the manufacturer should be consulted for details.

Applicable Specifications

Inspection and Documentation

Mill test certification for SB-574 includes chemical analysis, tensile results, heat number and dimensions. Because these grades are frequently used in wet-process equipment, we can supply intergranular corrosion testing to ASTM A262 as a supplementary requirement, and full material traceability from melt to finished rod. Third-party inspection by SGS, BV, TUV or Lloyd’s is welcome; name the inspection body in your inquiry.

Ordering Information

Please state the following when requesting a quotation:

• Grade and UNS number (for example N10276, C-276)
• Rod diameter in inches or millimetres
• Tensile grade requirement (Grade 1, 2 or 3) or the minimum tensile strength you need
• Length: mill length or cut-to-length, and straightness requirement
• Quantity and annual usage pattern
• Surface condition: hot-rolled, annealed, or machined
• Certification: EN 10204 3.1 or 3.2, and any supplementary tests such as ASTM A262
• Destination port and required delivery window

Send your sizes and quantities and we will return pricing, calculated weight and lead time. Diameter outside the listed range, or a grade not covered by SB-574, can often be sourced to a related specification — tell us what you need and we will confirm the correct route.

Related ranges: dimensional and standards background for this product is set out in our Monel 400 fittings. See also our Round Bars. Pressure class and facing data for every range is kept in one place.