Click on the image to check the artwork
By certification 
Detailed Description:
Standard:
Standard: ASTM A193 B7—ASTM A194 2H
ASTM A193 B7M—ASTM A194 2HM
ASTM A320 L7—ASTM A194 GR.7
ASTM A320 L7M—ASTM A194 GR7M
MATERIAL: 1040，1045，4140，4142
Surface protection: Plain, Hot dip galvanized, Galvanization, Dacroment, Xylan
Packing: Standard packing or According to customers' requirements
According to customers' Drawings and/or samples
Scope
Originally approved in 1936, 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.Below is a basic summary of a few of the common grades. ASTM A193 covers a number of other standard specifications not covered in this description including B5, B6, and B16.
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 |
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 |
Recommended Nuts and Washers
| 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 |
| B8M Class 2 | A194 Grade 8M | SS316 |
Strain hardened nuts available as a supplementary requirementnt
http://www.td-fasteners.com/
