ASTM A193/A193M-26 composition requirements and conditions
Standard reference requirements compiled from ASTM A193/A193M-26. Raw-material composition and the Class, heat treatment and performance conditions of finished components require separate confirmation; these are not actual supply or measured heat results.
Composition: Table 1, physical page 4; mass fraction wt%. Values are upper limits unless ranges, minimum values or conditional requirements are stated separately.
| Element | Requirement |
|---|---|
| C | ≤ 0.08 |
| Mn | ≤ 2.00 |
| P | ≤ 0.045 |
| S | ≤ 0.030 |
| Si | ≤ 1.00 |
| Cr | 17.0—19.0 |
| Ni | 9.0—12.0 |
| Mo | Not specified (must not be assumed 0) |
| Cu | Not specified (must not be assumed 0) |
| Nb | Not specified (must not be assumed 0) |
| Ti | 5×(C+N) to 0.70 |
| V | Not specified (must not be assumed 0) |
| Al | Not specified (must not be assumed 0) |
| N | ≤ 0.10 |
The variable lower limit is calculated using C or C+N from the same analysis; do not substitute 0 or convert it into a fixed range. Nb/Cb in the original table denote the same element, niobium.
Product-analysis tolerances are separate from the base composition ranges; intentional additions of Bi, Se, Te and Pb are prohibited.
Product-analysis tolerances (wt%, Table 1; must not be added directly to the base composition ranges)
| Element | Deviation |
|---|---|
| C | 0.01 |
| Mn | 0.04 |
| P | 0.010 |
| S | 0.005 |
| Si | 0.05 |
| Cr | 0.20 |
| Ni | 0.15 |
| Mo | Not listed in the original table (do not enter 0) |
| Cu | Not listed in the original table (do not enter 0) |
| Nb | Not listed in the original table (do not enter 0) |
| Ti | 0.05 downward |
| V | Not listed in the original table (do not enter 0) |
| Al | Not listed in the original table (do not enter 0) |
| N | Not listed in the original table (do not enter 0) |
Product-analysis tolerances are separate from the tabulated requirements. For the same element in the same heat, deviations must not occur both above and below the range. Unless otherwise stated, maximum values allow upward deviations only, ranges allow upward or downward deviations, and minimum values allow downward deviations only. Tolerances must not be added to the tabulated ranges in advance.
Customary-unit properties (Table 2)
Under 1.6, customary units apply unless the order or contract specifies the metric M edition. Under 1.7, the two unit systems are used independently and must not be mixed or combined through conversion. Properties are room-temperature requirements after the corresponding heat treatment; the specific Class, product form, specimen and order require separate confirmation.
| Grade | Class | Diameter condition | Heat treatment / minimum tempering temperature | Rm≥ ksi | Rp0.2≥ ksi | A4D≥ % | Z≥ % | Maximum hardness | Footnote | Physical page |
|---|---|---|---|---|---|---|---|---|---|---|
| B8T | 1 | All diameters | Carbide solution treatment | 75 | 30 | 30 | 50 | 223 HBW or 96 HRB | C | 6 |
| B8TA | 1A | All diameters | Carbide solution treatment in the finished condition | 75 | 30 | 30 | 50 | 192 HBW or 90 HRB | 6 | |
| B8T | 2 | Up to ¾ in | Carbide solution treatment and strain hardening | 125 | 100 | 12 | 35 | 321 HBW or 35 HRC | B,D | 6 |
| B8T | 2 | Over ¾ up to and including 1 in | Carbide solution treatment and strain hardening | 115 | 80 | 15 | 35 | 321 HBW or 35 HRC | B,D | 6 |
| B8T | 2 | Over 1 up to and including 1¼ in | Carbide solution treatment and strain hardening | 105 | 65 | 20 | 35 | 321 HBW or 35 HRC | B,D | 6 |
| B8T | 2 | Over 1¼ up to and including 1½ in | Carbide solution treatment and strain hardening | 100 | 50 | 28 | 45 | 321 HBW or 35 HRC | B,D | 7 |
- B: Class1 is solution treated; 1A is solution treated in the finished condition; 2 is solution treated and strain hardened. Strain-hardened austenitic steel over ¾ in may have nonuniform properties across the section.
- C: A maximum hardness of 241 HBW (100 HRB) is permitted for diameters up to ¾ in, only for rows marked C.
- D: For diameters of 1½ in and above, core properties may be lower than the reported test values measured at 1/2 of the radius.
Metric properties (Table 3)
Under 1.6, customary units apply unless the order or contract specifies the metric M edition. Under 1.7, the two unit systems are used independently and must not be mixed or combined through conversion. Properties are room-temperature requirements after the corresponding heat treatment; the specific Class, product form, specimen and order require separate confirmation.
| Grade | Class | Diameter condition | Heat treatment / minimum tempering temperature | Rm≥ MPa | Rp0.2≥ MPa | A4D≥ % | Z≥ % | Maximum hardness | Footnote | Physical page |
|---|---|---|---|---|---|---|---|---|---|---|
| B8T | 1 | All diameters | Carbide solution treatment | 515 | 205 | 30 | 50 | 223 HBW or 96 HRB | C | 8 |
| B8TA | 1A | All diameters | Carbide solution treatment in the finished condition | 515 | 205 | 30 | 50 | 192 HBW or 90 HRB | 8 | |
| B8T | 2 | Up to M20 | Carbide solution treatment and strain hardening | 860 | 690 | 12 | 35 | 321 HBW or 35 HRC | B,D | 8 |
| B8T | 2 | Over M20 up to and including M24 | Carbide solution treatment and strain hardening | 795 | 550 | 15 | 35 | 321 HBW or 35 HRC | B,D | 8 |
| B8T | 2 | Over M24 up to and including M30 | Carbide solution treatment and strain hardening | 725 | 450 | 20 | 35 | 321 HBW or 35 HRC | B,D | 8 |
| B8T | 2 | Over M30 up to and including M36 | Carbide solution treatment and strain hardening | 690 | 345 | 28 | 45 | 321 HBW or 35 HRC | B,D | 8 |
- B: Class 1 is solution treated; 1A is solution treated in the finished condition; 2 is solution treated and strain hardened. Strain-hardened austenitic steel over M20 may have nonuniform properties across the section.
- C: A maximum hardness of 241 HBW (100 HRB) is permitted for diameters up to M20, only for rows marked C.
- D: For diameters of M38 and above, core properties may be lower than the reported test values measured at 1/2 of the radius.
Product form, heat treatment and inspection limitations
- 6.2.1: Class 1, 1B, 1C (B8R/B8S only), and 2, 2B, 2C may apply to bar, wire and finished bolting components. Class 1A (all grades) and 1C (B8RA/B8SA only) apply only to finished bolting components. A finished-component Class must not be directly assigned as a raw-material wire Class.
- 6.2.1, 6.2.3: Class 1D applies to bar, wire and finished components machined directly from them without further hot or cold working. Hot-rolled/forged bars of the specified grades must be rapidly cooled immediately while above 954°C, and Class 1D service temperature must be below 454°C (the 454°C endpoint is excluded). This process description does not establish that arbitrary cold-drawn wire meets 1D.
- 6.2.4: Class 1A and the B8RA/B8SA grades of 1C require carbide solution treatment of finished components after all rolling, forging, heading and thread cutting/rolling have been completed. This does not apply to initial raw material such as bar.
- 6.2.5: Class 2, 2B, 2C require carbide solution treatment followed by strain hardening to achieve the corresponding properties. Grade or composition alone cannot establish compliance with these Classes.
- 9.1.1: Table 2/3 tensile requirements apply at room temperature after heat treatment. Strain-hardened stainless steel components (Class 2/2B/2C) are tested full-size after strain hardening. Where equipment capacity is insufficient, components over 1.500 in. in diameter may be tested using machined specimens. If full-size and specimen results conflict, the full-size results govern. The original dimensional condition is stated only in customary units; no metric endpoint is invented.
- 9.1.2, 12.1.3: Applicable headed components also require full-size wedge-load testing. The minimum wedge tensile load is calculated from the specified tensile strength and thread stress area. Units: ksi×in² gives kip (×1000 gives lbf); MPa×mm² gives N (÷1000 gives kN). Unnormalized products must not be labelled directly as lbf or kN. Verify the stress area under A962/A962M. Material-specimen properties do not replace applicable finished-component testing; confirm the applicable head type, size and length under 12.1.3.
- 9.2.1: Hardness requirements follow Table 2/3, with testing under A962/A962M or F606/F606M. A tabulated maximum hardness does not establish that finished-product hardness testing has been completed.
Contact: website@chqwire.net. This information is for technical material-selection reference only; it is not a quotation, contractual guarantee or heat-specific quality certificate. The applicable standard, order and material certificate govern.