| |
B8 /
B8M / B6 / B7 ( Half / Full Thread, Double Ended ) |
| |
|
| Material Grades: |
• A2 ( AISI 304 / AISI 304L ) / 1.4301 / 1.4306 / ASTM A193
B8 Cl.1 & Cl.2 /ASTM A320 B8 Cl.1 & Cl.2 / A2-50 / A2-70 / A2-80.
• A4 ( AISI 316 / AISI 316L ) / 1.4401 / 1.4404 / ASTM A193 B8M
Cl.1 & Cl.2 / ASTM A320 B8M Cl.1 & Cl.2 / A4-50 / A4-70 / A4-80.
• Stainless Steel "BS 1449" Grades 316S31 & 316S33
• AISI 410 / 1.4006 / ASTM A193 B6.
• ASTM A193 B7. • ASTM A194 |
| |
| Scope |
This specification is heavily utilized in
petroleum and chemical construction applications. The ASTM
standard covers alloy steel and stainless steel bolting
materials for high temperature or high pressure service. This
specification includes fasteners intended for use in pressure
vessels, valves, flanges, and fittings. Although, this material
is often available in national coarse (UNC) thread pitches, if
being used in traditional applications, threads are specified 8
threads per inch (tpi) for diameters above one inch. Further,
the same can be produced bearing threads BSW, BSF, fine pitch. |
| |
| Below is a basic summary of a few of the common grades. ASTM
A193 covers a number of other standard specifications. |
| |
|
A193 Grades |
| B7 |
Alloy steel,
AISI 4140/4142 quenched and tempered |
| B8 |
Class 1
Stainless steel, AISI 304, carbide solution treated. |
| B8M |
Class 1
Stainless steel, AISI 316, carbide solution treated. |
| B8 |
Class 2
Stainless steel, AISI 304, carbide solution treated, strain
hardened |
| B8M |
Class 2
Stainless steel, AISI 316, carbide solution treated, strain
hardened |
|
| |
| A193 Mechanical Properties |
| Grade |
Size |
Tensile ksi, min |
Yield, ksi, min |
Elong, %, min |
RA % min |
| B7 |
Up to 2-1/2 |
125 |
105 |
16 |
50 |
| 2-5/8 - 4 |
115 |
95 |
16 |
50 |
| 4-1/8 - 7 |
100 |
75 |
18 |
50 |
| B8 Class 1 |
All |
75 |
30 |
30 |
50 |
| B8M Class 1 |
All |
75 |
30 |
30 |
50 |
| B8 Class 2 |
Up to 3/4 |
125 |
100 |
12 |
35 |
| 7/8 - 1 |
115 |
80 |
15 |
35 |
| 1-1/8 - 1-1/4 |
105 |
65 |
20 |
35 |
| 1-3/8 - 1-1/2 |
100 |
50 |
28 |
45 |
| B8M Class 2 |
Up to 3/4 |
110 |
95 |
15 |
45 |
| 7/8 - 1 |
100 |
80 |
20 |
45 |
| 1-1/8 - 1-1/4 |
95 |
65 |
25 |
45 |
| 1-3/8 - 1-1/2 |
90 |
50 |
30 |
45 |
|
| |
| A193 Chemical Properties |
| Element |
B7 (AISI 4140) |
B8 (AISI 304) |
B8M (AISI 316) |
| Carbon |
0.37 - 0.49% |
0.08% max |
0.08% max |
| Manganese |
0.65 - 1.10% |
2.00% max |
2.00% max |
| Phosphorus, max |
0.035% |
0.045% |
0.045% |
| Sulfur, max |
0.040% |
0.030% |
0.030% |
| Silicon |
0.15 - 0.35% |
1.00% max |
1.00% max |
| Chromium |
0.75 - 1.20% |
18.0 - 20.0% |
16.0 - 18.0% |
| Nickel |
|
8.0 - 11.0% |
10.0 - 14.0% |
| Molybdenum |
0.15 - 0.25% |
|
2.00 - 3.00% |
|
| |
| A193 Recommended Hardware |
| Bolt Grade |
Nuts |
Washers |
| B7 |
A194 Grade 2H |
F436 |
| B8 Class 1 |
A194 Grade 8 |
SS304 |
| B8M Class 1 |
A194 Grade 8M |
SS316 |
| B8 Class 2 |
A194 Grade 8 |
SS304 |
|
| |
|
B8 Bolt and Nuts |
B8M Bolt and Nuts |
B7 Bolt and Nuts |
B6 Bolt and Nuts |
B8 / B8M / B6 / B7 (Half/Full Thread, Double Ended) |
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