ASTM A453 Grade 660 Stud Bolts

Class A/B/C/D

ASTM A453 Grade 660 Stud Bolts Class A, B, C & D offered at TorqBolt are manufactured in accordance with DIN 975, 976, 938, 939, 2510, 525, 2509, BS 2693, 3692, 4439, BS 4168, ASME B16.5, B18.31.2, B18.31.1M standards in metric and imperial coarse and fine thread sizes with UNC, UN, UNF, UNEF, UNJF & ISO threads.

Which ASTM A453 Grade 660 class do you need?

ASTM A453/A453M-17 sets four Grade 660 (UNS S66286) classes by heat treatment (Table 4) and strength (Table 5):

• ASTM A453 Grade 660 Class A Stud Bolts: 1650 °F [900 °C] solution treatment, 1325 °F [720 °C] age; 130 ksi [895 MPa] tensile, 85 ksi [585 MPa] yield, 24 to 37 HRC; stress-rupture tested for design temperatures above 800 °F [427 °C].
• ASTM A453 Grade 660 Class B Stud Bolts: 1800 °F [980 °C] solution treatment, 1325 °F [720 °C] age; 130 ksi [895 MPa] tensile, 85 ksi [585 MPa] yield, 24 to 37 HRC; stress-rupture tested for design temperatures above 800 °F [427 °C].
• ASTM A453 Grade 660 Class C Stud Bolts: 1800 °F [980 °C] solution treatment with oil quench, double aged at 1425 °F [775 °C] and 1200 °F [650 °C]; 130 ksi [895 MPa] tensile, 85 ksi [585 MPa] yield, 24 to 37 HRC.
• ASTM A453 Grade 660 Class D Stud Bolts: 105 ksi [725 MPa] yield up to 2½ in. [63.5 mm], 95 ksi [655 MPa] above; 24 to 35 HRC; no stress-rupture test, stamped NR. Covered by API 20F for BSL-2 and BSL-3 bolting.

Source: ASTM A453/A453M-17; API 20F. Last reviewed 20 October 2026.

ASTM A453 Grade 660 Stud Bolt Class

Imperial Range : 5/16" - 5"
Metric Range : M6 - M125

Section D - Stud Bolts For Pressure - Temperature Piping

Length

Inch

The lenght of the stud bolts, measured parallel to axis, is the distance from first thread to first thread. First thread is defined as the intersection of the major diameter of the thread with the base of the point.

Metric

The lenght of the stud bolts, measured parallel to axis, is the distance from each stud bolt, including the point.

ASTM A453 Grade 660 Stud Bolt Dimensional Standards