|
ASTM A193
Studs Specification-NINGBO BOLT |
﹛
ASTM A193 Studs Specification
The ASTM A193
specification covers alloy-steel and stainless steel stud bolts materials for
high temperature or high-pressure service.
ASTM A193 stud
bolts are available in national coarse (UNC) thread pitches, generally used in
traditional applications, which means that there are 8 threads per inch (※thread
per inch§) for rod diameters above 1 inch. B7 is the most common specification
grade for stud bolts.
Threaded stud
bolt
The most
common stud bolts materials covered by ASTM A193 are:
-
ASTM A193
B5
-
ASTM A193
B6
-
ASTM A193
B7: Alloy steel, AISI 4140/4142 quenched and tempered
-
ASTM A193
B7M
-
ASTM A193
B16
-
ASTM A193
B8: Class 1 Stainless steel, AISI 304, carbide solution treated.
-
ASTM A193
B8A
-
ASTM A193
B8M: Class 1 Stainless steel, AISI 316, carbide solution treated.
-
ASTM A193
B8MA
-
ASTM A193
B8T (SS 321)
-
ASTM A193
B8 Cl2: Class 2 Stainless steel, AISI 304, carbide solution treated, strain
hardened
-
ASTM A193
B8T Cl2
-
ASTM A193
B8M Cl2: Class 2 Stainless steel, AISI 316, carbide solution treated, strain
hardened
﹛
ASTM A193
Stud Bolts: Chemical Composition
|
Physical
Element |
ASTM A193
grade B7 (AISI 4140) |
ASTM A193
grade B8 (AISI 304) |
ASTM A193
grade B8M (AISI 316) |
|
Carbon |
0.38 每
0.48% |
0.08% max |
0.08% max |
|
Manganese |
0.75 每
1.00% |
2.00% max |
2.00% max |
|
Phosphorus,
max |
0.04% |
0.05% |
0.05% |
|
Sulfur, max |
0.04% |
0.03% |
0.03% |
|
Silicon |
0.15 每
0.35% |
1.00% max |
1.00% max |
|
Chromium |
0.80 每
1.10% |
18.0 每
20.0% |
16.0 每
18.0% |
|
Nickel |
absent |
8.0 每 11.0% |
10.0 每
14.0% |
|
Molybdenum |
0.15 每
0.25% |
absent |
2.00 每
3.00% |
ASTM A193 Stud
Bolts: Mechanical Properties
|
ASTM A193 |
Size |
Min Tensile
Strength, in ksi |
Min Yield
Strength, in ksi |
Min
Elongation, in % |
RA % min |
Max HBW |
Max HRC |
|
ASTM A193
grade B7 |
Up to 2-1/2 |
125 |
105 |
16 |
50 |
321 |
35 |
|
2-5/8 每 4 |
115 |
95 |
16 |
50 |
|
4-1/8 每 7 |
100 |
75 |
18 |
50 |
|
ASTM A193
grade B8 Class 1 |
All |
75 |
30 |
30 |
50 |
223 |
35 |
|
ASTM A193
grade B8M Class 1 |
All |
75 |
30 |
30 |
50 |
223 |
96 |
|
ASTM A193
grade B8 Class 2 |
Up to 3/4 |
125 |
100 |
12 |
35 |
321 |
35 |
|
7/8 每 1 |
115 |
80 |
15 |
35 |
|
1-1/8 每
1-1/4 |
105 |
65 |
20 |
35 |
|
1-3/8 每
1-1/2 |
100 |
50 |
28 |
45 |
|
ASTM A193
grade B8M Class 2 |
Up to 3/4 |
110 |
95 |
15 |
45 |
321 |
35 |
|
7/8 每 1 |
100 |
80 |
20 |
45 |
|
1-1/8 每
1-1/4 |
95 |
65 |
25 |
45 |
|
1-3/8 每
1-1/2 |
90 |
50 |
30 |
45 |
The material
chosen for the threaded stud and the hex nuts should be compatible. Materials
for bolting sets shall be selected based on the process＊s working temperatures,
as shown in the table below:
|
﹛ |
TEMPERATURE
∼C ( ∼F ) |
|
STUD BOLTS
MATERIALS |
MIN. |
MAX. |
|
CARBON
STEEL |
-29 (-20) |
300 (572) |
|
A193 B7, L7 |
-73 (-100) |
400 (752) |
|
A193 B6 |
0 (32) |
500 (932) |
|
A193 B8 |
-200 (-325) |
575 (1067) |
|
A193 B16 |
0 (32) |
520 (968) |
|
A193 B17B |
-29 (-20) |
650 (1202) |
|
A913
Inconel 718 |
0 (32) |
750 (1382) |
|
A453 Gr.
660 |
-29 (20) |
538 (1000) |
Stud bolts can
be produced also with ※dual certification,§ i.e. they conform to multiple sets
of ASTM standards (A193 B7 stud bolts can meet the requirements of A320 L7; B8
and B8m stud bolts also typically conform to both A193 and A320).
STUD BOLTS AND NUTS SELECTION (SERVICE vs.
GRADE)
The material
to use for stud bolts depends on multiple factors, the main ones are the
material of the flanges and the pipeline design temperature:
|
DESIGN |
FLANGE
MATERIAL |
STUD BOLT |
HEAVY HEX
STEEL NUTS |
|
TEMPERATURE |
|
-195∼ to
102∼C |
ASTM A 182
Gr. F304, F304L, F316, F316L, F321, F347 |
A320 Gr. B8
Class 2 |
A194 Gr. 8A |
|
-101∼ to
-47∼C |
ASTM A 350
Gr. LF3 |
A 320 Gr.
L7 |
A 194 Gr. 7 |
|
-46∼ to
-30∼C |
ASTM A 350
Gr. LF2 |
A 320 Gr.
L7 |
A 194 Gr. 7 |
|
-29∼ to
427∼C |
ASTM A 105 |
A 193 Gr.
B7 |
A 194 Gr.
2H |
|
428∼ to
537∼C |
ASTM A 182
Gr. F11, F22 |
A 193 Gr.
B16 |
A 194 Gr.
2H |
|
538∼ to
648∼C |
ASTM A182
Gr. F11, F22 |
A 193 Gr.
B8 Class 1 |
A 194 Gr.
8A |
|
649∼ to
815∼C |
ASTM A182
Gr. F304 H, F316 H |
A 193 Gr.
B8M Class 1 |
A 194 Gr.
8A |
﹛ |
