ASTM A453 Grade 660 Class D specification provides a yield strength viz. 95 ksi 655 MPa respectively for use in high temperature service for bolting components such as Stud bolts, screws, nuts, hex bolts & various other fasteners for pressure vessel and valve flanges. A453 Grade 660 Class D is equivalent to Class A or Class B provided teh respective heat treatment cycles are matched while manufacturing in single age hardened condition A453 Grade 660 Cl D Studs and nuts are capable of meeting impact test requirements of 70 joules minimum at - 196 Degrees Centigrade. ASTM A453 Grade 660 Class D is produced in various other forms like wire rods, round bars, shafts, castings, forgings, threaded bars, threaded rods, wires, tubings, sheets, plates, welding rods, hex bars, Rivets & Springs. ASTM A453 Grade 660 Cl. D is high yeild Bolting material and hence stress rupture test is not required. A453 Gr. 660 Class D Bolting has to be certified under nace with the maximum hardness not over 35HRC. Class D Fasteners are certified under API 20F Specification under qualification requirements of BSL-2 & BSL-3. ASTM A453 Grade 660 Class D UNS S66286 Bolting Duly certified under NORSOK M630 Edition 2020 in accordance with MDS S39 Revision 1. with impact testing @ -101 Degrees C is manufactured at TorqBolt.
| Grade | ASTM A453 Grade 660 Class D | |
|---|---|---|
| UNS Number | S66286 | |
| Elements | Content, % | Product Analysis Variation, Over or Under, % |
| Carbon (C) | 0.08 max | 0.01 over |
| Manganese (Mn) | 2.00 max | 0.04 |
| Phosphorus (P) | 0.040 max | 0.005 over |
| Sulfur (S) | 0.030 max | 0.005 over |
| Silicon (Si) | 1.00 max | 0.05 |
| Nickel (Ni) | 24.0-27.0 | 0.2 |
| Chromium (Cr) | 13.5-16.0 | 0.2 |
| Molybdenum (Mo) | 1.00-1.50 | 0.05 |
| Titanium (Ti) | 1.90-2.35 | 0.05 |
| Aluminum (Al) | 0.35 max | 0.05 over |
| Vanadium (V) | 0.10-0.50 | 0.03 |
| Boron (B) | 0.001-0.010 | 0.0004 under to 0.001 over |
| Grade | ASTM A453/A453M Grade 660 | ||
|---|---|---|---|
| Class | D (≤2 1 / 2 in. [63.5 mm]) | D (>2 1 / 2 in. [63.5 mm]) | |
| Tensile Strength,min | ksi | 130 | 120 |
| MPa | 895 | 825 | |
| Yield Strength(0.2 % Offset), min | ksi | 105 | 95 |
| MPa | 725 | 655 | |
| Elongation in 4× Diam, min, % | 15 | 15 | |
| Reduction of Area, min, % | 18 | 18 | |
| Brinell Hardness Number | 248-321 | 248-321 | |
| Approximate Rockwell Hardness,B and C | min | 24 HRC | 24 HRC |
| max | 35 HRC | 35 HRC | |
| Hardness as per API 20F BSL2 & BSL3* | 35 HRC | 35 HRC | |
|
|||
ASTM A453/A453M Grade 660D solution treated and age hardened bolting as stated in API 20F should not be used on pressure containing and high load bearing connectors in the following situations :
| Grade Symbol | Class | Solution Treatment | Hardening Treatment |
|---|---|---|---|
| ASTM A453/A453M Grade 660 | D | 1650 ± 25 °F [900 ± 14 °C], hold 2 h min, and liquid quench or 1800 ± 25 °F [980 ± 14 °C], hold 1 h min, and liquid quench | 1325 ± 25 °F [720 ± 14 °C], hold 16 h, air cool If necessary to achieve properties, second age: 1200 ± 25 °F [650 ± 14 °C] hold 16 h, air cool |
|
|||
| Diameter, in. [mm] | Weight, lb [kg] |
|---|---|
| To 13/4 [44] | 3000 [1400] |
| Over 13/4 [44] to 21/2 [63] | 6000 [2700] |
| Over 21/2 [63] | 12000 [5400] |
| Diameter, in. [mm] | Maximum Lot Size, lb [kg] |
|---|---|
| 11/2 [38] and under | 200 [90] |
| Over 11/2 [38] to 13/4 [44], incl | 300 [140] |
| Over 13/4 [44] to 21/2 [63], incl | 600 [270] |
| Over 21/2 [63] | 20 pieces |
| Grade | Marking |
|---|---|
| ASTM A453 Grade 660 Class D | TB 660D M1/M2/R1/R2 NR |
| ASTM A453 Grade 660 Class D BSL2 | TB NR 660D API 20F2 Heat No. |
| ASTM A453 Grade 660 Class D BSL3 | TB NR 660D API 20F3 Heat No. |
| Specification | Grade | UNS No. | CLASS | Type | |||
|---|---|---|---|---|---|---|---|
| ASTM A453/A453M | Grade 660 | S66286 | Class D | M1 | M2 | R1 | R2 |
Based on the application & Usage
