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ASTM A320 Gr L7 Stud Bolts

Manufacturer of SA 320 L7m Bolts and Nuts in India

These are used with pressure valves, pressure vessels, boilers and other application bolts. The ASTM A320 Grade L7 Studs come in four different classes. They can be of Class A, B, C or D. The difference in the class is mainly the tensile strength. The classes A, B and C have 895MPa minimum tensile strength and 585MPa minimum yield strength. The class D of the Astm A320 Grade L7 Material has 895MPa minimum tensile strength and 725MPa minimum yield strength. The material is made up of carbon, manganese, phosphorus, sulfur, silicon, 24% nickel, 13% chromium, molybdenum, titanium, aluminum, vanadium and boron. The ASTM A320 Grade L7m Bolts range in thread diameters from M6 through M36. The thread configuration varies according to different standards such as the ASME B1.1 2A/3A and so on. The Astm A320 L7m Stud Bolts can be rolled, forged, strain hardened and heat treated for the application requirements. Regal Sales Corporation is a leading manufacturer and supplier of the different types of ASTM A320 Grade L7 Nuts in different dimensions. Please feel free to contact us for more information on the products such as the ASTM A320 L7 Carbon Steel Bolts and their pricing.

ASTM A320 Grade L7 Nuts

ASTM A320 Grade L7 Nuts

ASTM A320 L7m Stud Bolts

ASTM A320 L7m Stud Bolts

ASTM A320 Grade L7 Bolts

ASTM A320 Grade L7 Bolts

Table of Content



What do you mean by ASTM A320 Grade L7 Bolts ?


ASTM A320 L7 Stud Bolts are used in high temperature bolting applications. The ASTM A320 is for bolts, nuts, studs and other fasteners intended for high tensile and rupture risk applications. The ASTM A320 Stainless Steel Bolts are of high tensile strength and have high rupture and stress resistance properties.


ASTM A320 Bolts Specification format


Standards and Grades A320 : Grade L7, L7M, B8, B8M
Neck type Triangular, Square, Hex, Oval & Knurled etc
Thread Requirements ASME B1.1, UNC & UNF, Class 2A (Fastenal will inspect and accept parts with a 1A no-go gauge)
Certification
Dual Certified As per ASTM & ASME Codes
Additional Requirements
NACE MR0103 / MR0175 / ISO 15156 Compliance
Dimensions
ASME B18.2.1, B18.3
Threads Configuration
ASME B1.1 2A/3A Inch Unified Threads and B1.13M 6h Metric Coarse Threads
Head Hex, T-head & Triangular, Round, Square, Flat, Hex flange etc
Additional Certifications
PED 97/23/EC Certified, Merkblatt AD 2000 W2 Certified


A320 Heavy Hex Bolts Standard Dimensions


A320 Heavy Hex Bolts Standard Dimensions

Diameter (D) Body Diameter (D) Across the Flats (F) Across the Corners © Head Height (H) Thread Lengths (T)
MAX MIN MAX MIN MAX MIN MAX MIN <6” >6”
1/2 0.515 0.482 0.875 0.85 1.01 0.969 0.364 0.302 1.25 1.5
5/8 0.642 0.605 1.062 1.031 1.227 1.175 0.444 0.378 1.5 1.75
7/8 0.895 0.852 1.438 1.394 1.66 1.589 0.604 0.531 2 2.25
1 1.022 0.976 1.625 1.575 1.876 1.796 0.7 0.591 2.25 2.5
1 1/4 1.277 1.223 2 1.938 2.309 2.209 0.876 0.749 2.75 3
1 3/8 1.404 1.345 2.188 2.119 2.526 2.416 0.94 0.81 3 3.25
1 3/4 1.785 1.716 2.75 2.662 3.175 3.035 1.196 1.054 3.75 4
2 2.039 1.964 3.125 3.025 3.608 3.449 1.388 1.175 4.25 4.5
2 1/2 2.559 2.461 3.875 3.75 4.474 4.275 1.708 1.479 5.25 5.5
2 3/4 2.827 2.711 4.25 4.112 4.907 4.688 1.869 1.632 5.75 6
3 3.081 2.961 4.625 4.475 5.34 5.102 2.06 1.815 6.25 6.5

ASTM A320 Grade L7m Bolts Torque Chart


BOLT
DIA		 Torque FT-LBS
30% Initial
Torque		 70%
Torque		 100% Final
Torque
1/2 16 36 52
5/8 31 73 104
3/4 55 129 184
1 107 249 356
1.1/8 127 297 424
1.1/4 179 417 596
1.1/2 246 574 821
1.9/16 168 392 560
1.3/4 240 561 801
1.7/8 298 696 994
2.1/4 529 1234 1762
2.1/2 733 1709 2442
2.3/4 986 2300 3285
BOLT
DIA		 Torque Nm
30% Initial
Torque		 70%
Torque		 100% Final
Torque
9/16 31 72 102
5/8 42 99 141
3/4 75 175 249
7/8 96 225 321
1.1/8 172 403 575
1.1/4 243 565 808
1.1/2 334 778 1113
1.9/16 228 531 759
1.5/8 259 603 862
1.7/8 404 944 1348
2 496 1157 1653
2.1/4 717 1673 2389
2.3/4 1337 3118 4454
3 1748 4078 5826


ASTM A320 L7m Stud Bolts Sizing Chart


ASTM A320 L7m Stud Bolts Sizing Chart

Equivalent grades of ASTM A320 Grade L7 Nuts


L7
AISI 4140/4142 Quenched and tempered
L7M
AISI 4145 Quenched and tempered
L43
AISI 4340 Quenched and tempered
B8 Class 1
AISI 304, carbide solution treated
B8 Class 2
AISI 304, carbide solution treated, strain hardened
B8M Class 1
AISI 316, carbide solution treated
B8M Class 2
AISI 316, carbide solution treated, strain hardened


ASTM A320 Stainless Steel Bolts Mechanical Strength


Grade
Size
Tensile ksi, min
Yield, ksi, min
Elong, %, min
RA % min
Charpy Impact
20-ft-lbf
@ temp
L7
Up to 2-1/2
125
105
16
50
-150° F
L43
Up to 4
125
105
16
50
-150° F
B8 Class 1
All
75
30
30
50
N/A
B8 Class 2
Up to 3/4
125
100
12
35
N/A
7/8 - 1
115
80
15
35
N/A
1-1/8 - 1-1/4
105
65
20
35
N/A
1-3/8 - 1-1/2
100
50
28
45
N/A
B8M Class 1
All
75
30
30
50
N/A
B8M Class 2
Up to 3/4
110
95
15
45
N/A
7/8 - 1
100
80
20
45
N/A
1-1/8 - 1-1/4
95
65
25
45
N/A
1-3/8 - 1-1/2
90
50
30
45
N/A

Chemical Formula of ASTM A320 L7 Stud Bolts


Element
L7 (AISI 4140)
L43 (AISI 4340)
B8 (AISI 304)
B8M (AISI 316)
Carbon
0.37 - 0.49%
0.38 - 0.43%
0.08% max
0.08% max
Manganese
0.65 - 1.10%
0.75 - 1.00%
2.00% max
2.00% max
Phosphorus, max
0.035%
0.035%
0.045%
0.045%
Sulfur, max
0.040%
0.040%
0.030%
0.030%
Silicon
0.15 - 0.35%
0.15 - 0.35%
1.00% max
1.00% max
Chromium
0.75 - 1.20%
0.70 - 0.90%
18.0 - 20.0%
16.0 - 18.0%
Nickel
1.65 - 2.00%
8.0 - 11.0%
10.0 - 14.0%
Molybdenum
0.15 - 0.25%
0.02 - 0.30%
2.00 - 3.00%

Application of ASME SA320 GR L7 Bolt


  • Petrochemicals
  • Sea Water Equipment
  • Gas Processing
  • Pharmaceuticals
  • Power Generation

ASTM Fasteners