ASTM Threaded Studs
ASTM Threaded - Studs
ASTM A193, Grade B7
A heat treated chromium-molybdenum steel widely used for medium high temperature service. (Liquid quench -50 to 900°F. Air quench -40 to 900°F)
ASTM A193, Grade B7M
Similar to B7 studs except that the minimum yield and tensile strength requirements are reduced and the hardness controlled to 235 Brinell maximum. Designed for use in corrosive environments. (-50 to 900°F)
ASTM A193, Grade B16
A heat treated chromium-molybdenum steel for high pressure, high temperature service. (-50 to 1100°F)
ASTM A320, Grade L7
This grade is intended for low temperature service down to minus 150°F and has a minimum Charpy impact value of 20 F. lbs. at this temperature. (-50 to 1100°F)
ASTM A320, Grade L7M
Similar to L7 studs except that the minimum yield and tensile strength requirements are reduced and the hardness controlled to 235 Brinell maximum. This stud is designed for use in low temperature corrosive environments. (-150 to 1100°F)
ASTM A320, Grade L43
This grade is intended for low temperature service down to minus 150°F and has a minimum Charpy impact value of 20 F. lbs. at this temperature. Available in sizes up to 4 in. (-150 to 1100°F)
ASTM A193, Grade B8
These Chromium-Nickel (AISI 304) austenitic steel studs are used in corrosive environments. (-325 to 1500°F)
ASTM A193, Grade B8M
These Chromium-Nickel Molybdenum (AISI 316) austenitic steel studs are used in corrosive environments. (-325 to1500°F)
Mechanical Requirements
ASTM A193/A193M
ASTM A194/A194M
ASTM A320/A320M
STUDS
STUDS NOTES
- To meet the tensile requirements, the Brinell hardness shall be over 200 HB (93 HRB).
- Class 1 is solution-treated. Class 2 is solution-treated and strain-hardened. Austenitic steels in the strain-hardened condition may not show uniform properties throughout the section particularly in sizes over 3/4” in diameter.
- For sizes 3/4” in diameter and smaller, a maximum hardness of 241 HB (100 HRB) is permitted.
- To meet the tensile requirements, the Brinell hardness shall not be less than 200 HB or 93 HRB.
| ASTM A193 ASTM A320 |
MINIMUM TEMPERING TEMP. °F (°C) |
TENSILE STRENGTH MIN. KSI (MPA) |
YIELD STRENGTH MIN. KSI. (MPA) |
ELONGATION 2" (50mm) MIN. % |
REDUCTION OF AREA MIN. % |
HARDNESS MAXIMUM |
|
|---|---|---|---|---|---|---|---|
| GRADE | SIZE | ||||||
| B7 | 2-1/2” and under | 1100 (593) | 125 (860) | 105 (725) | 16 | 50 | 321 HB (35HRC) |
| over 2-1/2” to 4” | 1100 (593) | 115 (790) | 95 (655) | 16 | 50 | 321 HB (35HRC) |
|
| B7M Note 1 |
2-1/2” and under | 1150 (620) | 100 (690) | 80 (550) | 18 | 50 | 235 HB (99HRB) |
| over 2-1/2” to 4” | 1150 (620) | 100 (690) | 80 (550) | 18 | 50 | 235 HB (99HRB) |
|
| ASTM A193 ASTM A320 |
MINIMUM TEMPERING TEMP. °F (°C) |
TENSILE STRENGTH MIN.KS1 (MPA) |
YIELD STRENGTH MIN. KSI (MPA) |
ELONGATION 2" (50mm) MIN. % |
REDUCTION OF AREA MIN. % |
HARDNESS MAXIMUM |
|
|---|---|---|---|---|---|---|---|
| GRADE | SIZE | ||||||
| L7 | 2-1/2” and under | Quenched and Tempered 1100 (593) |
125 (860) | 105 (725) | 16 | 50 | |
| L7M Note 4 |
2-1/2” and under | Quenched and Tempered 1150 (620) |
100 (690) | 80 (550) | 18 | 50 | 235 HB (99HRB) |
| ASTM A193 ASTM A320 |
MINIMUM TEMPERING TEMP. °F (°C) |
TENSILE STRENGTH MIN. KSI (MPA) |
YIELD STRENGTH MIN. KSI. (MPA) |
ELONGATION 2" (50mm) MIN. % |
REDUCTION OF AREA MIN. % |
HARDNESS MAXIMUM |
|
|---|---|---|---|---|---|---|---|
| GRADE | SIZE | ||||||
| B8 Class 1 Note 2, 3 |
All Diameters |
Carbide Solution Treated |
75 (515) | 30 (205) | 30 | 50 | 223 HB (96HRB) |
| B8 Class 2 Note 2 |
3/4” and under | Carbide Solution Treated and Strain Hardened | 125 (860) | 100 (690) | 12 | 35 | 321 HB (35HRC) |
| over 3/4” to 1” |
115 (790) | 80 (550) | 15 | 35 | |||
|
over 1” to 1-1/4” |
105 (725) | 65 (450) | 20 | 35 | |||
| over 1-1/4” to 1-1/2" |
100 (690) | 50 (345) | 28 | 35 | |||
| ASTM A193 ASTM A320 |
MINIMUM TEMPERING TEMP. °F (°C) |
TENSILE STRENGTH MIN. KSI (MPA) |
YIELD STRENGTH MIN. KSI. (MPA) |
ELONGATION 2" (50mm) MIN. % |
REDUCTION OF AREA MIN. % |
HARDNESS MAXIMUM |
|
|---|---|---|---|---|---|---|---|
| GRADE | SIZE | ||||||
| B8M Class 1 Note 2, 3 |
All Diameters |
Carbide Solution Treated |
75 (515) | 30 (205) | 30 | 50 | 223 HB (96HRB) |
| B8M Class 2 Note 2 |
3/4” and under | Carbide Solution Treated and Strain Hardened | 110 (760) | 95 (655) | 15 | 45 | 321 HB (35HRC) |
| over 3/4” to 1” |
100 (690) | 80 (550) | 20 | 45 | |||
|
over 1” to 1-1/4” |
95 (655) | 65 (450) | 25 | 45 | |||
| over 1-1/4” to 1-1/2" |
90 (620) | 50 (345) | 30 | 45 | |||
NUTS
| ASTM A-194 | ASME SA-194 | MINIMUM AVERAGE TEMPERING |
BRINELL HARDNESS |
ROCKWELL HARDNESS |
||
|---|---|---|---|---|---|
| GRADE | CLASS AND SIZE | TEMP °F (°C) | C SCALE | B SCALE | |
| 2H | Up to and including 1-1/2" | 850 (455) | 248 - 327 | 24 - 35 | 95 min. |
| Over 1-1/2" | 212 - 327 | 35 max. | |||
| 2HM | All Sizes | 1150 (620) | 159 - 235 | 84 to 99 | |
| L7M | All Sizes | 1150 (620) | 159 - 235 | 84 to 99 | |
| 7L | All Sizes | 1100 (595) | 248 - 327 | 24 - 35 | |
| B8 and B8M | All Sizes | 126 - 300 | 32 max | 60 min | |
* In order to meet the tensile requirements, the hardness shall be no less than 200 HB or 93 HRB .
Impact Energy Absorption Requirements
Bolting for Low-Temperature Service
| ASTM A320 | A320M | MINIMUM AVERAGE IMPACT VALUE FOR EACH SET OF 3 SAMPLES 10 x 10 x 50mm K. - lbs. (Joules) |
|
|---|---|---|
| GRADE | TEST TEMP. °F (°C) |
|
| L7 | -150 (-101) | 20 (27) |
| L7M | -100 (-73) | 20 (27) |
| L43 | -150 (-101) | 20 (27) |
