STS Industrial - Bolts & Screws

 

ASTM A320 GRADE B8M CLASS 2 STAINLESS STEEL STUD BOLTS

GOVERNING STANDARDS:
ASTM A320/A320M Standard specification for alloy-steel and stainless steel bolting for low temperature service.
ASME B16.5 Covers recommended stud bolt quantity, diameter, and length for use in flanged pipe fittings.
ASME B1.1 Class 2A Specifies the thread form, series, class, allowance, tolerance, and desig nation for unified screw threads. UNC for 1″ diameter and smaller. UN8 (8 threads per inch) for 1-1/8″ diameter and larger.

 

APPLICATIONS:

Non-magnetic, strain hardened 316 stainless steel with better corrosion resistance than A320 Grade B8 Stud Bolts. For use in low temperature applications where certain corrosives or harsh atmospheric conditions exist, and additional tensile strength over A320 B8M Stud Bolts is required.

B8M Class 2 Stud Bolt Material Marking

Product to be marked with the manufacturer’s marking and grade marking on one end of each stud 3/8″ diameter and larger. Manufacturer’s marking may be placed on other end if insufficient space. 

MATERIAL PROPERTIES:
Stainless Steel, AISI 316, Carbide Solution Treated and Strain Hardened

DIAMETER

PROOF LOAD

YIELD STRENGTH

TENSILE STRENGTH

CORE HARDNESS

 3/4″ and Under 95,000 psi  110,000 psi  C35 Max
 7/8″ through 1″

 80,000 psi  100,000 psi

 C35 Max

 1-1/8″ through 1-1/4″

 65,000 psi  95,000 psi

 C35 Max

 1-3/8” through 1-1/2”

 50,000 psi  90,000 psi

 C35 Max

Elongation 15% Minimum for Diameters through 3/4”, 20% for 7/8″ through 1″, 25% for 1-1/8″ through 1-1/4″, 30% for 1-3/8″ through 1-1/2″
Reduction of Area 45% Minimum for Diameters
Material strengths listed are minimum acceptable per governing standard. Core hardness based on Rockwell scale.
STUD REFERENCE CHART:

The chart below gives the recommended stud bolt diameter, length, and quantity for a given flange size.

FLANGE NOMINAL PIPE DIAMETER (in.)
RATING BOLTING 1/2 3/4 1 1-1/4 1-1/2 2 2-1/2 3 3-1/2 4
150# Number 4 4 4 4 4 4 4 4 8 8
Diameter 1/2 1/2 1/2 1/2 1/2 5/8 5/8 5/8 5/8 5/8
Stud Bolt Length 2-1/4 2-1/2 2-1/2 2-3/4 2-3/4 3-1/4 3-1/2 3-1/2 3-1/2 3-1/2
Mach Bolt Length 2 2 2-1/4 2-1/4 2-1/2 2-3/4 3 3 3 3
300# Number 4 4 4 4 4 8 8 8 8 8
Diameter  1/2  5/8  5/8  5/8  3/4  5/8  3/4  3/4  3/4  3/4
Stud Bolt Length 2-1/2 3 3 3-1/4 3-1/2 3-1/2 4 4-1/4 4-1/4 4-1/2
Mach Bolt Length 2-1/4 2-1/2 2-1/2 2-3/4 3 3 3-1/4 3-1/2 3-3/4 3-3/4
600# Number 4 4 4 4 4 8 8 8 8 8
Diameter  1/2  5/8  5/8  5/8  3/4  5/8  3/4  3/4  7/8  7/8
Stud Bolt Length 3 3-1/2 3-1/2 3-3/4 4-1/4 4-1/4 4-3/4 5 5-1/2 5-3/4
900# Number 4 4 4 4 4 8 8 8 8
Diameter  3/4  3/4  7/8  7/8 1  7/8 1 7/8 1-1/8
Stud Bolt Length 4-1/4 4-1/2 5 5 5-1/2 5-3/4 6-1/4 5-3/4 6-3/4
1500# Number 4 4 4 4 4 8 8 8 8
Diameter  3/4  3/4  7/8  7/8 1  7/8 1 1-1/8 1-1/4
Stud Bolt Length 4-1/4 4-1/2 5 5 5-1/2 5-3/4 6-1/4 7 7-3/4
2500# Number 4 4 4 4 4 8 8 8 8
Diameter  3/4  3/4  7/8 1 1-1/8 1 1-1/8 1-1/4 1-1/2
Stud Bolt Length 4-3/4 5 5-1/2 6 6-3/4 7 7-3/4 8-3/4 10
FLANGE NOMINAL PIPE DIAMETER (in.)
RATING BOLTING 5 6 8 10 12 14 16 18 20 24
150# Number 8 8 8 12 12 12 16 16 20 20
Diameter 3/4 3/4 3/4 7/8 7/8 1 1 1-1/8 1-1/8 1-1/4
Stud Bolt Length 3-3/4 4 4-1/4 4-1/2 4-3/4 5-1/4 5-1/4 5-3/4 6-1/4 6-3/4
Mach Bolt Length 3-1/4 3-1/4 3-1/2 4 4 4-1/2 4-1/2 5 5-1/2 6
300# Number 8 12 12 16 16 20 20 24 24 24
Diameter  3/4  3/4  7/8 1 1-1/8 1-1/8 1-1/4 1-1/4 1-1/4 1-1/2
Stud Bolt Length 4-3/4 4-3/4 5-1/2 6-1/4 6-3/4 7 7-1/2 7-3/4 8 9
Mach Bolt Length 4-1/4 4-1/4 4-3/4 5-1/2 5-3/4 6-1/4 6-1/2 6-3/4 7-1/4 8
600# Number 8 12 12 16 20 20 20 20 24 24
Diameter 1 1 1-1/8 1-1/4 1-1/4 1-3/8 1-1/2 1-5/8 1-5/8 1-7/8
Stud Bolt Length 6-1/2 6-3/4 7-1/2 8-1/2 8-3/4 9-1/4 10 10-3/4 11-1/4 13
900# Number 8 12 12 16 20 20 20 20 20 20
Diameter 1-1/4 1-1/8 1-3/8 1-3/8 1-3/8 1-1/2 1-5/8 1-7/8 2 2-1/2
Stud Bolt Length 7-1/2 7-1/2 8-3/4 9-1/4 10 10-3/4 11-1/4 12-3/4 13-3/4 17-1/4
1500# Number 8 12 12 12 16 16 16 16 16 16
Diameter 1-1/2 1-3/8 1-5/8 1-7/8 2 2-1/4 2-1/2 2-3/4 3 3-1/2
Stud Bolt Length 9-3/4 10-1/4 11-1/2 13-1/4 14-3/4 16 17-1/2 19-1/2 21-1/4 24-1/4
2500# Number 8 8 12 12 12
Diameter 1-3/4 2 2 2-1/2 2-3/4
Stud Bolt Length 11-3/4 13-1/2 15 19-1/4 21-1/4

 

 

All dimensions in inches unless otherwise noted.

Sources: ASTM Standards for Mechanical Fasteners and Related Processes 2nd Edition, Inch Fastener Standards 8th Edition

Note: All material included on this page is informational only, and should not be used as one’s sole source for design purposes. STS Industrial, Inc. and its affiliates do not guarantee the accuracy of the information on this site, and retain no liability for the use or misuse of the information contained on this site.