Forgings, Fasteners, Boltings, Stud Bolts, Screws, Nuts
ASTM A266/ A266M specification consists of carbon steel forgings for pressure vessel components. A266 Standard specification delegates four different grades of carbon steel forgings used boilers, pressure vessels, and associated equipment applications.: Grade 1, Grade 2, Grade 3, and Grade 4. The UNS number designation for each grade is K03506 [Grade 1], K03506 [Grade 2], K05001 [Grade 3], and K03017 [Grade 4], respectively. These forgings are manufactured in heat treated condition namely annealed, normalized, normalized and tempered & Quenched and tempered. The most commonly used forgings manufactured in accordance with ASTM A266 include tube sheets, hubbed flat heads, or nozzles, that are ordered for ASME Boiler and Pressure Vessel Code applications.
| Composition, % | Element | ||||
|---|---|---|---|---|---|
| C, max | Mn | P, max | S, max | Si | |
| ASTM A266 Grades 1 and 2 | 0.30 | 0.40-1.05 | 0.025 | 0.025 | 0.15-0.35 |
| ASTM A266 Grade 3 | 0.35 | 0.80-1.35 | 0.025 | 0.025 | 0.15-0.35 |
| ASTM A266 Grade 4 | 0.30 | 0.80-1.35 | 0.025 | 0.025 | 0.15-0.35 |
| Grade | ASTM A266 Grade 1 | ASTM A266 Grades 2 and 4 | ASTM A266 Grade 3 |
|---|---|---|---|
| Tensile strength, min, ksi [MPa] | 60-85 [415-585] | 70-95 [485-655] | 75-100 [515-690] |
| Yield strength (0.2 % offset), min, ksi [MPa] | 30 [205] | 36 [250] | 37.5 [260] |
| Elongation in 2 in. or 50 mm, min, % | 23 | 20 | 19 |
| Reduction of area, min, % | 38 | 33 | 30 |
| S1 | Rough Turning and Boring |
|---|---|
| S2 | Alternative Tension Test Orientation |
| S3 | Hydrostatic Test |
| S4 | Magnetic Particle Examination |
| S5 | Liquid Penetrant Examination |
| S6 | Macroetch Test |
| S7 | Product Analysis |
| S8 | Specimen Location on Forged Hubs |
| S9 | Hardness |
| S10 | Grain Size |
| S11 | Restriction on Residual Elements (Applicable to Heat Analysis) |
| S12 | Restriction on Carbon (Applicable to Grade I) |
| S13 | Impact Tests |
| S14 | Individual Forging |
| S15 | Carbon Equivalancy |