Introduction
ASTM A453/A453M Grade 660 Class A/B/C/D specifies high-quality stainless steel bolting products designed for high-temperature applications. The product range includes precision-manufactured Stud Bolts, Hex Bolts, Heavy Hex Bolts, Socket Head Cap Screws, Threaded Rods, Nuts, and Washers.
Key product features:
- Size Range: 3/8″ to 4″ (imperial); up to M100 (metric). Larger sizes are available via custom order (per drawings/requests).
- Base Material: Grade 660 (equivalent to UNS S66286 / Alloy A286). Premium and surplus bar stock of this material is stocked for fast manufacturing and shortened delivery times.
- Quality Certification: All products are supplied with EN 10204 Type 3.1 Material Test Certificate (MTC) for traceability.
- Testing Support: Rupture test facilities are offered for orders with sufficient quantity.
ASTM A453 Grade 660 Tensile Class
Detailed specifications for each tensile class (Class A, B, C, D) are defined to meet high-temperature performance requirements.
ASTM A453 Grade 660 Chemical Composition (UNS S66286)
The chemical composition of Grade 660 (UNS S66286) adheres to the following limits (by weight percentage):
| Element | Content (%) |
|---|---|
| Carbon (C) | 0.08 max |
| Manganese (Mn) | 2.00 max |
| Phosphorus (P) | 0.04 max |
| Sulfur (S) | 0.03 max |
| Silicon (Si) | 1.00 max |
| Nickel (Ni) | 24.00 – 27.00 |
| Chromium (Cr) | 13.50 – 16.00 |
| Molybdenum (Mo) | 1.00 – 1.50 |
| Titanium (Ti) | 1.90 – 2.35 |
| Aluminum (Al) | 0.35 max |
| Vanadium (V) | 0.10 – 0.50 |
| Boron (B) | 0.001 – 0.010 |
ASTM A453 Grade 660 Class A/B/C/D Mechanical Properties
Mechanical performance requirements vary slightly by class, with key parameters (minimum/maximum values) as follows:
| Grade | Class | Tensile Strength | Yield Strength | Elongation (in 4D, min) | Reduction of Area (min) | Brinell Hardness Number | Approximate Rockwell Hardness |
|---|---|---|---|---|---|---|---|
| Ksi / MPa | Ksi / MPa | % | % | Min – Max | B / C | ||
| Grade 660 | A, B, C | 130 / 895 | 85 / 585 | 15 | 18 | 248 – 341 | – / 24 – 37 |
| Grade 660 | D | 130 / 895 | 105 / 725 | 15 | 18 | 248 – 341 | – / 24 – 35 |
ASTM A453 Grade 660 Class A/B/C/D Heat Treatment Requirements
Heat treatment (solution treatment + hardening/aging treatment) is tailored to each class to ensure optimal high-temperature performance:
| Grade | Class | Solution Treatment | Hardening/Aging Treatment |
|---|---|---|---|
| Grade 660 | A | 1650 ± 25°F (900 ± 14°C), hold 2 hr (min), liquid quench | 1325 ± 25°F (720 ± 14°C), hold 16 hr, air cool |
| Grade 660 | B | 1800 ± 25°F (980 ± 14°C), hold 1 hr (min), liquid quench | 1325 ± 25°F (720 ± 14°C), hold 16 hr, air cool |
| Grade 660 | C | 1800 ± 25°F (980 ± 14°C), hold 1 hr (min), oil quench | 1425 ± 25°F (775 ± 14°C), hold 16 hr, air cool → 1200 ± 25°F (650 ± 14°C), air cool |
| Grade 660 | D | Option 1: 1650 ± 25°F (900 ± 14°C), hold 2 hr, liquid quenchOption 2: 1800 ± 25°F (980 ± 14°C), hold 1 hr, liquid quench | 1325 ± 25°F (720 ± 14°C), hold 16 hr, air cool.Second age (if needed): 1200 ± 25°F (650 ± 14°C), air cool. |
ASTM A453 Grade 660 Class A/B/C/D Stress Rupture Requirements
For Class A, B, and C, stress rupture testing is required under the following conditions:
| Grade | Class | Test Temperature | Minimum Stress | Minimum Time to Rupture | Minimum Elongation |
|---|---|---|---|---|---|
| °F / °C | Ksi / MPa | min / h | % | ||
| Grade 660 | A, B, C | 1200 / 650 | 56 / 385 | 100 / 1.67 | 5 |
Note: Test specimens must be tested continuously at the specified temperature/stress. Rupture time must not be less than the stated minimum.
ASTM A453 Grade 660 Class A/B/C/D Marking Requirements
Each class of bolting product requires distinct marking for identification:
| Grade | Class A | Class B | Class C | Class D |
|---|---|---|---|---|
| Grade 660 | BPF 660A | BPF 660B | BPF 660C | BPF 660D NR |