| Metric class ISO 898-1 | Tensile (MPa / ksi) | Min. yield* (MPa) |
Nearest SAE J429 grade | SAE tensile (ksi) | Common ASTM equivalents | Typical head marking |
|---|---|---|---|---|---|---|
| 4.6 | 400 / 58 | 240 | Grade 1 | 60 | A307 Grade A | 4.6 (or unmarked) |
| 4.8 | 420 / 61 | 340† | †Grade 2 | 74 | A307 Grade A (nearest) | 4.8 |
| 5.8 | 520 / 75 | 420† | Grade 2 (≤3/4") | 74 | — | 5.8 |
| 8.8 | 800–830 / 116–120 | 640–660 | Grade 5 | 120 | A449 · F3125 Gr. A325 (structural) | 8.8 / 3 radial dashes (Gr. 5) |
| 9.8 | 900 / 130 | 720 | between Gr. 5 and 8 | — | — | 9.8 |
| 10.9 | 1040 / 151 | 940 | Grade 8 | 150 | A354 Gr. BD · F3125 Gr. A490 (structural) | 10.9 / 6 radial dashes (Gr. 8) |
| 12.9 | 1220 / 177 | 1100 | no SAE equivalent | — | A574 (socket head cap screws, 170/180 ksi) | 12.9 |
No rows match that filter.
*Yield shown as ISO 898-1 minimum lower yield (ReL) for classes ≤6.8 and 0.2% proof stress (Rp0.2) for 8.8 and above. †Classes 4.8 and 5.8 have no specified yield in ISO 898-1; figures shown are the nominal values implied by the class designation. "Nearest SAE grade" means closest mechanical performance, not interchangeability — thread forms (metric vs UNC), dimensional standards, and head markings all differ. For structural bolting, substitution between A325/A490 and metric classes is governed by the project specification, not this table. Stainless classes (A2-70, A4-80 per ISO 3506 / ASTM F593) are covered in the standards index.