Bolting Information pertaining to ASTM A193
description
Transcript of Bolting Information pertaining to ASTM A193
ASTM A193
Quick Links
Hex Bolts
A193 All Thread Rod
ASTM A194
Thread Pitch Chart
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, minElong, %,
minRA % 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 All 75 30 30 50
Grade Size Tensile ksi, min Yield, ksi, minElong, %,
minRA % min
1
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
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%
Recommended Nuts and Washers
Bolt Grade Nuts Washers
B7 A194 Grade 2H F436
B8 Class 1 A194 Grade 8 SS304
B8M Class 1A194 Grade
8MSS316
B8 Class 2 A194 Grade 8 SS304
B8M Class 2A194 Grade
8MSS316
Hex Bolts
A307A F1554 A449 A354 F593 SAE J429
Hex bolts (six sided heads) are the industry standard for fasteners with forged heads. ASTM A307 grade A bolts, all SAE hex bolts, and several other common specifications require a standard (finished) hex head. For specifications such as A307 grade B, A325 and A490 that require a heavy hex pattern, refer to dimensional tolerances for heavy hex bolts or structural bolts.
Applications
Hex bolts can be used for many different applications that include fastening wood, steel, and other construction materials for projects such as docks, bridges, highway structures, and buildings. Hex bolts with forged heads are also commonly used as headed anchor bolts.
Manufacturing
Manufactured hex bolts from 1/2" diameter through 2-1/2" diameter in most ASTM, AASHTO, and SAE specifications
Standard Thread Length
Bolt lengths ≤ 6": Thread length = (2 X diameter) + 1/4"Bolt lengths > 6": Thread length = (2 X diameter) + 1/2"Note: Most stock hex bolts 10" and longer will have 6" of thread.
Dimensions
Bolt Diameter
D F C H
Body Diameter Width Across Flats Width Across Corners Height
Max Basic Max Min Max Min Basic Max Min
3/8 0.388 9/16 0.562 0.544 0.650 0.620 1/4 0.268 0.226
1/2 0.515 3/4 0.750 0.725 0.866 0.826 11/32 0.364 0.302
5/8 0.642 15/16 0.938 0.906 1.083 1.033 27/64 0.444 0.378
3/4 0.768 1-1/8 1.125 1.088 1.299 1.240 1/2 0.524 0.455
7/8 0.895 1-5/16 1.312 1.269 1.516 1.447 37/64 0.604 0.531
1 1.022 1-1/2 1.500 1.450 1.732 1.653 43/64 0.700 0.591
1-1/8 1.149 1-11/16 1.688 1.631 1.949 1.859 3/4 0.780 0.658
1-1/4 1.277 1-7/8 1.875 1.812 2.165 2.066 27/32 0.876 0.749
1-3/8 1.404 2-1/16 2.062 1.994 2.382 2.273 29/32 0.940 0.810
1-1/2 1.531 2-1/4 2.250 2.175 2.598 2.480 1 1.036 0.902
1-3/4 1.785 2-5/8 2.625 2.538 3.031 2.893 1-5/32 1.196 1.054
2 2.039 3 3.000 2.900 3.464 3.306 1-11/32 1.388 1.175
2-1/4 2.305 3-3/8 3.375 3.262 3.897 3.719 1-1/2 1.548 1.327
2-1/2 2.559 3-3/4 3.750 3.625 4.330 4.133 1-21/32 1.708 1.479
Dimensions per ASME B18.2.1 1996
Heavy Hex Bolts
A307B F1554 A325 A490 A193 A320
Several ASTM specifications require a hex head that is larger than a standard (finished) hex head. These
specifications include: A193, A320 and A307B. Although A325 and A490 bolts also require a heavy hex
head, please refer to Structural Bolts for dimensional specifications, since these bolts have shorter thread
lengths than standard heavy hex bolts.
Applications
Heavy hex bolts can be used for many different applications that include fastening wood, steel, and other
construction materials for projects such as docks, bridges, highway structures, and buildings. Heavy hex
bolts with forged heads are also commonly used as headed anchor bolts.
Manufacturing
Portland Bolt manufactures heavy hex bolts from 1/2" diameter through 2-1/2" diameter in most ASTM,
AASHTO, and SAE specifications. Special tooling can be created to produce nonstandard head
dimensions or bolt heads with your company's name and/or logo.
Standard Thread Lengths
Bolt lengths < 6": Thread length = (2 X diameter) + 1/4"
Bolt lengths > 6": Thread length = (2 X diameter) + 1/2"
Dimensions
Bolt Diameter
D F C H
Body Diameter Width Across Flats Width Across Corners Height
Max Basic Max Min Max Min Basic Max Min
1/2 0.515 7/8 0.875 0.850 1.010 0.969 11/32 0.364 0.302
5/8 0.642 1-1/16 1.062 1.031 1.227 1.175 27/64 0.444 0.378
3/4 0.768 1-1/4 1.250 1.212 1.443 1.383 1/2 0.524 0.455
7/8 0.895 1-7/16 1.438 1.394 1.660 1.589 37/64 0.604 0.531
1 1.022 1-5/8 1.625 1.575 1.876 1.796 43/64 0.700 0.591
1-1/8 1.149 1-13/16 1.812 1.756 2.093 2.002 3/4 0.780 0.658
1-1/4 1.277 2 2.00 1.938 2.309 2.209 27/32 0.876 0.749
1-3/8 1.404 2-3/16 2.188 2.119 2.526 2.416 29/32 0.940 0.810
1-1/2 1.531 2-3/8 2.375 2.300 2.742 2.622 1 1.036 0.902
1-3/4 1.785 2-3/4 2.750 2.662 3.175 3.035 1-5/32 1.196 1.054
2 2.039 3-1/8 3.125 3.025 3.608 3.449 1-11/32 1.388 1.175
2-1/4 2.305 3-1/2 3.500 3.388 4.041 3.862 1-1/2 1.548 1.327
2-1/2 2.559 3-7/8 3.875 3.750 4.474 4.275 1-21/32 1.708 1.479
Dimensions per ASME B18.2.1 1996
Heavy Hex Nuts
A563 A194 F594
ASTM A194 Nut Compatibility Chart
Grade of Bolt A194 Heavy Hex Nut Grade
A193 Grade B7 2H
A193 Grade B8 (Class 1 and 2) 8
A193 Grade B8M (Class 1 and 2) 8M
A320 Grade L7 4 or 7
A320 Grade B8 (Class 1 and 2) 8
A320 Grade B8M (Class 1 and 2) 8M
For Class 2 stainless steel grades, strain hardened nuts available as a supplementary requirement
Heavy hex nuts are slightly larger and thicker than standard (finished) hex nuts. There are numerous
grades and the heavy pattern is typically used for large diameter and high strength bolts. See the nut
compatibility chart above to determine the compatible heavy hex nut(s) for a specific grade of bolt. Since
hot-dip galvanizing typically adds 2.2 to 5 mils of thickness to the threaded portion of a fastener,
galvanized heavy hex nuts are tapped oversize to compensate for the corrosion resistant coating on the
bolts.
Stock
Diameters: 3/8" - 2-3/4"
Origin: Domestic and import
Finish: Black and hot-dip galvanized
Grades: A563 (grades A, C, and DH), A194 grade 2H
Dimensions
Nominal Size
F C HWeight
Per Nut
Width Across Flats Width Across Corners Thickness
Basic Max Min Max Min Basic Max Min
3/8 11/160.68
80.669 0.794 0.763 23/64 0.377 0.341 0.03
1/2 7/80.87
50.850 1.010 0.969 31/64 0.504 0.464 0.07
5/8 1-1/161.06
21.031 1.227 1.175 39/64 0.631 0.587 0.12
3/4 1-1/41.25
01.212 1.443 1.382 47/64 0.758 0.710 0.20
7/8 1-7/161.43
81.394 1.660 1.589 55/64 0.885 0.833 0.30
1 1-5/81.62
51.575 1.876 1.796 63/64 1.012 0.956 0.43
1-1/8 1-13/161.81
21.756 2.093 2.002 1-7/64 1.139 1.079 0.59
1-1/4 22.00
01.938 2.309 2.209 1-7/32 1.251 1.187 0.79
1-3/8 2-3/162.18
82.119 2.526 2.416 1-11/32 1.378 1.310 1.02
1-1/2 2-3/82.37
52.300 2.742 2.622 1-15/32 1.505 1.433 1.31
1-5/8 2-9/162.56
22.481 2.959 2.828 1-19/32 1.632 1.556 1.62
1-3/4 2-3/4 2.75 2.662 3.175 3.035 1-23/32 1.759 1.679 2.04
Nominal Size
F C HWeight
Per Nut
Width Across Flats Width Across Corners Thickness
Basic Max Min Max Min Basic Max Min
0
1-7/8 2-15/162.93
82.844 3.392 3.242 1-27/32 1.886 1.802 2.41
2 3-1/83.12
53.025 3.608 3.449 1-31/32 2.013 1.925 2.99
2-1/4 3-1/23.50
03.388 4.041 3.862 2-13/64 2.251 2.155 4.19
2-1/2 3-7/83.87
53.750 4.474 4.275 2-29/64 2.505 2.401 5.64
2-3/4 4-1/44.25
04.112 4.907 4.688 2-45/64 2.759 2.647 7.38
3 4-5/84.62
54.475 5.340 5.102 2-61/64 3.013 2.893 9.50
3-1/4 55.00
04.838 5.774 5.515 3-3/16 3.252 3.124 11.94
3-1/2 5-3/85.37
55.200 6.207 5.928 3-7/16 3.506 3.370 15.26
3-3/4 5-3/45.75
05.562 6.640 6.341 3-11/16 3.760 3.616 18.12
4 6-1/86.12
55.925 7.073 6.755 3-15/16 4.014 3.862 21.80
Dimensions per ASME B18.2.2 1987 (1999)
Standard Thread Pitches
Thread series cover designations of diameter/pitch combinations that are measured by the number of
threads per inch (TPI) applied to a single diameter.
Coarse Thread Series (UNC/UNRC) is the most common designation for general application bolts and
nuts. Coarse thread is beneficial, because they are less likely to cross thread, more tolerant in adverse
conditions and facilitate quick assembly.
Fine Thread Series (UNF/UNRF) is commonly used in precision applications. Because of the larger
tensile stress areas, they have high tension strength. However, a longer engagement is required for fine
thread applications than for coarse series threads to prevent stripping.
8 - Thread Series (8UN) is the specified thread forming method for several ASTM standards including
A193 B7, A193 B8/B8M, and A320. This series is used for diameters one inch and above.
Coarse Thread Series - UNC Fine Thread Series - UNF 8-Thread Series - 8UN
Nominal Size and
Threads Per In.
Basic Pitch Dia.
Section at
Minor Dia.
Tensile
Stress Area
Nominal Size and
Threads Per In.
Basic Pitch Dia.
Section at
Minor Dia.
Tensile
Stress Area
Nominal Size and
Threads Per In.
Basic Pitch Dia.
Section at
Minor Dia.
Tensile
Stress Area
In. Sq in. Sq in. In. Sq in. Sq in. In. Sq in. Sq in.
3⁄8 - 160.334
40.0678 0.0775 3⁄8 - 24
0.3479
0.0809 0.0878 -- -- -- -- --
7⁄16 - 140.391
10.0933 0.1063 7⁄16 - 20
0.4050
0.1090 0.1187 -- -- -- -- --
1⁄2 - 130.450
00.1257 0.1419 1⁄2 - 20
0.4675
0.1486 0.1599 -- -- -- -- --
9⁄16 - 120.508
40.162 0.182 9⁄16 - 18
0.5264
0.189 0.203 -- -- -- -- --
5⁄8 - 110.566
00.202 0.226 5⁄8 - 18
0.5889
0.240 0.256 -- -- -- -- --
3⁄4 - 100.685
00.302 0.334 3⁄4 - 16
0.7094
0.351 0.373 -- -- -- -- --
7⁄8 - 90.802
80.419 0.462 7⁄8 - 14
0.8286
0.480 0.509 -- -- -- -- --
1 - 80.918
80.551 0.606 1 - 12
0.9459
0.625 0.663 1 - 80.918
80.551 0.606
11⁄8 - 71.032
20.693 0.763 11⁄8 - 12
1.0709
0.812 0.856 11⁄8 - 81.043
80.728 0.790
11⁄4 - 71.157
20.890 0.969 11⁄4 - 12
1.1959
1.024 1.073 11⁄4 - 81.168
80.929 1.000
13⁄8 - 61.266
71.054 1.155 13⁄8 - 12
1.3209
1.260 1.315 13⁄8 - 81.293
81.155 1.233
11⁄2 - 61.391
71.294 1.405 11⁄2 - 12
1.4459
1.521 1.581 11⁄2 - 81.418
81.405 1.492
-- -- -- -- -- -- -- -- -- -- 15⁄8 - 81.543
81.68 1.78
13⁄4 - 51.620
11.74 1.90 -- -- -- -- -- 13⁄4 - 8
1.6688
1.98 2.08
-- -- -- -- -- -- -- -- -- -- 17⁄8 - 81.793
82.30 2.41
2 - 41⁄21.855
72.30 2.50 -- -- -- -- -- 2 - 8
1.9188
2.65 2.77
21⁄4 - 4-1⁄2
2.1057
3.02 3.25 -- -- -- -- -- 21⁄4 - 82.168
83.42 3.56
21⁄2 - 42.337
63.72 4.00 -- -- -- -- -- 21⁄2 - 8
2.4188
4.29 4.44
23⁄4 - 42.587
64.62 4.93 -- -- -- -- -- 23⁄4 - 8
2.6688
5.26 5.43
3 - 42.837
65.62 5.97 -- -- -- -- -- 3 - 8
2.9188
6.32 6.51
31⁄4 - 4 3.087 6.72 7.10 -- -- -- -- -- 31⁄4 - 8 3.168 7.49 7.69
Coarse Thread Series - UNC Fine Thread Series - UNF 8-Thread Series - 8UN
Nominal Size and
Threads Per In.
Basic Pitch Dia.
Section at
Minor Dia.
Tensile
Stress Area
Nominal Size and
Threads Per In.
Basic Pitch Dia.
Section at
Minor Dia.
Tensile
Stress Area
Nominal Size and
Threads Per In.
Basic Pitch Dia.
Section at
Minor Dia.
Tensile
Stress Area
In. Sq in. Sq in. In. Sq in. Sq in. In. Sq in. Sq in.
6 8
31⁄2 - 43.337
67.92 8.33 -- -- -- -- -- 31⁄2 - 8
3.4188
8.75 8.96
33⁄4 - 43.587
69.21 9.66 -- -- -- -- -- 33⁄4 - 8
3.6688
10.11 10.34
4 - 43.837
610.61 11.08 -- -- -- -- -- 4 - 8
3.9188
11.57 11.81
Fastener Identification Markings Bolt Strength Requirements
Grade Marking
Specification
Material and
Treatment
Nominal Size (In.)
Mechanical PropertiesHardness Rockwell
Proof
LoadMin(ksi)
YieldStrengt
hMin(ksi)
TensileStrengt
hMin(ksi)
Elong % Min
[9]
RA % Min
[10]
Min
Max
SAE J429Grade 1
Low or Medium Carbon Steel
1⁄4" - 11⁄2" 33 36 60 18 35 B70B10
0
A307Grade A
1⁄4" - 4"
-</< td>
- 60 18 - B69B10
0
A307Grade B
- -60 min
100 max18 - B69 B95
One End Green
A307Grade C [7] - 36
58 min80 max
23 - - -
One End Blue
F1554Grade 36
- 3658 min80 max
23 40 - -
One End Yellow
F1554Grade 55
1⁄4" - 2"
- 5575 min95 max
21 30
- -
21⁄4"- 21⁄2" 21 22
23⁄4" - 3" 21 20
31⁄4" - 4" 21 18
SAE J429Grade 2 [8]
1⁄4" - 3⁄4"
7⁄8" - 11⁄2"
55
33
57
36
74
60
18
1835
B80
B70
B100
B100
A193/A320Grade B8Class 1
AISI SS304 Stainless
No Restriction
s
- 30 75 30 50 - B96
A193/A320Grade B8M
AISI SS316 Stainless
Steel
A325Type 1
Medium Carbon
Steel, Q & T 1⁄2" - 1"
11⁄8" - 11⁄2"
85
74
92
81
120
10514 35
C24
C19
C35
C31
A325Type 3
Atmospheric Corrosion
Resistant Steel, Q & T
SAE J429Grade 5
Medium Carbon
Steel, Q & T
1⁄4" - 1"
11⁄8" - 11⁄2"
85
74
92
81
120
10514 35
C25
C19
C34
C30
A449Type 1
1⁄4" - 1"
11⁄8" - 11⁄2"
15⁄8" - 3"
85
74
55
92
81
58
120
105
90
14 35
C25
C19
B91
C34
C30
B100
A449Type 3
Weathering Steel, Q &
T
1⁄4" - 1"
11⁄8" - 11⁄2"
15⁄8" - 3"
85
74
55
92
81
58
120
105
90
14 35
C25
C19
B91
C34
C30
B100
A193Grade B7
Medium Carbon
Alloy Steel,
Q & T
1⁄4" - 21⁄2"
25⁄8" - 4"
41⁄8" - 7"
-
105
95
75
125
115
100
16
16
18
50
50
50
-
C35
C35
C35
A354Grade BC
1⁄4" - 21⁄2"
25⁄8" - 4"
105
95
109
94
125
115
16
16
50
45
C26
C22
C36
C33
One End Red
F1554Grade 105
1⁄4" - 3" - 105125 min150 max
15 45 - -
A320Grade L7
AISI 4140, 4142, or
4145
1⁄4" - 21⁄2" - 105 125 16 50 - -
A320Grade L43
AISI 4340 1⁄4" - 4" - 105 125 16 50 - -
A490Type 1
Medium Carbon
Alloy Steel,
Q & T1⁄2" - 11⁄2" 120 130
150 min173 max
14 40 C33 C38
A490Type 3
Atmospheric Corrosion
Resistant Steel, Q & T
SAE J429Grade 8 Medium
Carbon Alloy Steel,
Q & T
1⁄4" - 11⁄2" 120 130 150 12 35 C33 C39
A354Grade BD [6]
1⁄4" - 21⁄2"
25⁄8" - 4"
120
105
130
115
150
14014 40
C33
C31
C39
C39
1. All specifications are ASTM unless otherwise noted.
2. All specifications shall be marked by the manufacturer with a unique identifier to identify the
manufacturer or private label distributor, as appropriate.
3. Q & T - Quenched and Tempered.
4. Although markings are shown on hex heads, stamping is a requirement on one end of rods and
studs. The exception is F1554 and A307 grade C in which stamping is a supplemental
requirement while color coding is required.
5. Although markings are shown on hex heads, grade markings apply equally to products with other
head configurations.
6. All Grade BD products shall be marked "BD". In addition to the "BD" marking, the product may be
marked with 6 radial lines 60° apart.
7. ASTM A307 grade C has been replaced by ASTM F1554 grade 36.
8. Grade 2 requirements for diameters ranging from 1/4" through 3/4" only apply to headed
fasteners up to and including 6" in length, and to studs of all lengths. For headed fasteners longer
than 6", see SAE J429 grade 1.
9. Percent Elongation
10. Percent Reduction of Area
"-" = no requirement.
Hex Bolts vs. Hex Cap Screws
What are the differences between a hex cap screw and a hex bolt?
These terms are often incorrectly used interchangeably. The variations between these fasteners are fairly
significant both from a manufacturing perspective and application standpoint. Generally speaking, hex
cap screws are used in precise applications like an OEM setting where tight tolerances are required. Hex
bolts are often specified when the mechanical properties are more important than dimensional tolerances,
like the construction industry. For example, SAE J429 Grade 2 is typically provided as a hex cap screw,
whereas ASTM A307-A is a common hex bolt specification.
Below is an overview of some of the specifics these fasteners are required to meet.
Hex cap screws
Flat washer facing under the head that meet specific tolerances as described under ASME
B18.2.1-1996.
They will usually be manufactured by a cold-heading process (large runs of standard sizes) or
turned CNC operation.
A radius under the head at the shank.
Body diameter of plus nothing, minus .011″ for an 1-1/4″ diameter fastener.
Some common fastener specifications unless otherwise specified: ASTM A449 and SAE J429
Grade 2, 5, and 8.
Hex bolts
A die seam across the bearing surface is permissible.
The typical bolt is manufactured by hot-forging process.
Allows a reduced body diameter to be not less than the minimum pitch diameter of the thread.
Some common fastener specifications unless otherwise specified: ASTM A307-A, A354, and
F1554.
This list is not inclusive, but represents some of the differences between these two designations.
High Pressure Bolting – Studs
First to First Stud bolts for High Pressure Temperature Piping
REFERENCEStud bolts for pressure-temperature applications conform to the requirements of ANSI/ASME B16.5, Steel Pipe Flanges and Flanged Fittings.
LENGTH-FIRST TO FIRSTThe length of stud bolt, measured parallel to the axis, is the distance from first thread to first thread. First thread is defined as the intersection of the major diameter of the thread with the base of the point. Please see the drawing above-this is confusing to most users!! Stud bolts are normally available in 1/4 inch length increments. Length tolerances, all stud bolt sizes, shall be as tabulated below:
Length, in. Length Tolerance, in.to 12 +/-0.062
over 12 to 18 +/-0.125
over 18 +/-0.250
POINTSPoints shall be flat and chamfered, or sheared at option of the manufacturer. When points are flat and chamfered, the diameter of the flat shall not exceed the minor diameter of the thread, and shall be not less than one or more than two complete threads as measured from the extreme end parallel to the axis.
THREADSThreads shall be Unified inch coarse thread series (UNC), Class 2A, for all stud bolt sizes 1 in. and smaller, and Unified inch 8 thread series (8 UN), Class 2A, for all stud bolts larger than 1 in., in accordance with ANSI/ASME B1.1. Acceptability of screw threads shall be determined based on ANSI/ASME B1.3.
MATERIALChemical and mechanical requirements shall be specified by the purchaser and shall be in accordance with applicable ASME, ASTM, and ANSI codes and specifications current at the time of ordering.
DESIGNATIONIt is recommended that stud bolts be designated in the following sequence: product name, nominal size, threads per inch, length, material, and protective finish, if required.
Example: ANSI/ASME B16.5 stud bolt,5/8-11 x 3-1/2, ASTM A193, Grade B7, Zinc & Clear Chromate Plated
Bolting And Ring Gasket Requirements
ASME/ANSI B16.5 – 1996 – Pipe Flanges and Flanged Fittings
The ASME B16.5 – 1996 Pipe Flanges and Flange Fittings, flange bolt and gasket standard covers pressure-temperature ratings, materials, dimensions, tolerances, marking, testing, and methods of designating openings for pipe flanges and flanged fittings.
The standard includes flanges with rating class designations 150, 300, 400, 600, 900, 1500, and 2500 in sizes NPS 1/2 through NPS 24, with requirements given in both metric and U.S units. The Standard is limited to flanges and flanged fittings made from cast or forged materials, and blind flanges and certain reducing flanges made from cast, forged, or plate materials. Included in this Standard are requirements and recommendations regarding flange bolting, flange gaskets, and flange joints. The standard covers the required number of bolts, diameter of the stud bolts, length of stud bolts and ring size in R, 1RF, RTJ, and RX gaskets.
TORQUE FOR FLANGE BOLTING (B7/L7 STUDS)*
ANSI / API 6A / ISO 10423:2003 Feb. 1, 2005
ASTM A193 Grade B7 Tensile and Yield Strength2 1/2″ and under – tensile 125 ksi; yield strength 105 ksiOver 2 1/2″ to 4″ – tensile 115 ksi; yield 95 ksiOver 4″ to 7″ – tensile 100; yield 75 ksi ASTM A320 L7 Tensile and Yield StrengthOnly covers 2 1/2″ and under - tensile 125 ksi; yield strength 105 ksiSource: API 6-A, 19th Appendix D, Table D1 &D2
Stud Diameter Tension PTFE Coated Bolt coefficient of Friction Plain Bolt coefficient of Friction
Size Ibf Torque Torque Torque Torque
Inch Nm Ft. lbs Nm Ft. lbs
f=0.07 f=0.07 f=0.13 f=0.13
1/2″ 7450 48 35 80 59
5/8″ 11865 92 68 155 115
3/4″ 17559 160 118 270 200
7/8″ 24241 253 188 429 319
1″ 31802 376 279 639 474
1 1/8″ 41499 540 401 925 686
1 1/4″ 52484 745 553 1285 953
1 3/8″ 64759 996 739 1727 1281
1 1/2″ 78322 1297 962 2261 1677
1 5/8″ 93173 1653 1226 2894 2146
1 3/4″ 109313 2069 1534 3636 2696
1 7/8″ 126741 2549 1890 4493 3332
2″ 145458 3097 2297 5476 4061
2 1/4″ 186758 4418 3276 7851 5822
2 1/2″ 233212 6068 4500 10828 8030
2 5/8″ 233765 6394 4716 11429 8430
2 3/4″ 257694 7354 5424 13168 9712
3″ 309050 9555 7047 17156 12654
3 1/4″ 365070 12154 8965 21878 16136
3 3/4″ 491099 18685 13782 33766 24905
3 7/8″ 525521 20620 15208 37293 27506
4″ 561108 22683 16730 41057 30282
*This chart is for general practice purposes only and should not be in the engineering or design of any products. The most current edition of the API specification may be obtained on the API
Standards website to make sure you have the most current edition of API 6A. For most the accurate references in critical situations torque values should be replaced with field measured tension values. Accurate stud tension is difficult to attain using torque, because friction has a significant effect on the torque–tension relationship. Any thread damage (however minor), additional lubrication, or standard deviations within the range can change friction and thereby the expected outcome.
B7M BoltsFebruary 19, 2010 by Sigma Fasteners · Leave a Comment
ASTM A193 Grade B7M Bolt
B7M Studs
Bolt Description:
B7M bolts for High Temperature and/or High Pressure service are modified in our tempering furnace to meet the ASTM A193 /A193M – B7M standard for bolting covering both metric and inch bolting products. The A193 B7M standard covers threaded rod, bolts, studs, and stud bolts. In accord with the A193 standard the final modification is the tempering at 1150° F minimum performed after all machining, roll threading and any type of cutting. The tempering furnace recording chart is kept on record with your order maintaining complete traceability of your final product. Tensile and 100% hardness records are also available and kept with your order.
Typical Usage:
Typical use for B7M bolting includes sour gas service where Hydrogen Sulfide gas exposure may lead to Hydrogen embrittlement problems in hard alloys.
Product marking:
All B7M bolting which has been 100% hardness tested must be marked B7M and will have the Sigma Trademarked S for manufacturer’s identification.
Testing:
B7M bolts are 100% indentation hardness tested to ensure conformance to the standard. Tensile Tests are performed after tempering.
Nuts:
ASTM A194 2HM heavy hex nuts are most commonly used with ASTM A193 B7M bolts.
Xylan Coated Bolts
Coated Stud Bolts
Xylan Coated Stud Bolts
Xylan 1010, 1070, 1014, 1052 and now 1424 have been used as bolt coatings for almost a quarter century now. Most major Oil and Chemical Companies recognizing that maintenance is a huge issue have made coated bolt specifications for bolted high pressure flange connections. The various properties on the Xylan give excellent make up and brake out torque and reduce the need for high risk cutting torches or high cost bolt cutting when maintenance is required.
Xylan 1014 in bolt coatings used for its good lubricity, chemical and abrasion resistance.
Xylan 1052 for coated bolts used for its excellent lubricity.
Xylan 1070 and 1010 where the pioneers in the field – used for the lubricity and chemical inertness.
With VOCs an ever present issue these days Whitford has made a low VOC version 1424 which Sigma applies to achieve the results need in a coated bolt connection and to stay complaint in a green economy.
Xylan coated bolts come in many tints and the coated bolts are often coordinated with standard corporate color branding schemes. While very light shades are possible most of the popular hues range from a Dark Yellow to black with Reds and Blues and greens being the most widespread.
Stud Bolts
Stud Bolts
Stud bolts are available in ASTM Grades B7, L7, B16, B16M, L7M, B8, 660 and B8M; they are also available exotic metals such as Monel, Titanium, Inconel, Alloy 20, and Hastelloy, 17-4PH. These studs are also available with industrial coatings such as SermaGard, Xylan, PTFE, Fluoropolymers and other coatings.
Stud Bolts for Pressure-Temperature Piping
Continuous Thread Studs (Fully Threaded Studs)
Stud bolts are threaded end to end and are often used for flange bolting with two nuts on either end.
There are two types of these studs.
Type one – usually for general purpose; the length of stud is measured from end to end. Threads are UNRC-2A.
Type two – studs for high temperature pressure piping. These studs are made to dimensional standard requirements of ANSI B16.5 the length of this stud is measured from first thread to first thread, exclusive of points. Threads are UNRC-2A for sizes 1 inch and under and 8 UNR-2A for sizes over 1 inch. The length of stud bolt, measured parallel to the axis, is the distance from first thread to first thread. First thread is defined as the intersection of the major diameter of the thread with the base of the point.
L7M Bolts
ASTM L7M Custom Bolts
ASTM A320 Grade L7M bolting is designed for low temperature sour gas service where there is high concentration of Hydrogen Sulfide gases present in production situation. Per the specification at Sigma Fasteners we have our own heat treating furnace and hardness testing equipment for onsite L7M modification and hardness testing. All L7M bolts require 100% hardness testing