ASTM A193 B7 stud bolt with two ASTM A194 2H Heavy Hex Nuts hot dipped galvanized to A153 ASTM F2329
ASTM A193 Grade B7 stud bolts are typically used in flange bolting applications. ASTM A193 covers the requirements for high temperature and high pressure bolting. A193 B7 full hread studs, as well as hex bolts having diameters above 1″ are most common 8UN (8 threads per inch).
The ASTM A193-B7 (Grade B7), is the specification for a heat-treated chrome-moly steel used for medium high temperature service. Rods that meet this specification are either made from AISI 4140 or 4142.
Diameter range from 1/4″ up through 2 1/2″, they must meet minimum yield strength of 105 KSI, and minimum tensile strength of 125 KSI.
A stud bolt is an externally threaded rod with two heavy hexagon nuts. It has a plain shank, with rolled threads on both ends. The threading helps ensure that the nuts remain secure and prevent the bolt from breaking during installation or removal.
- Fully threaded stud bolt – also called as continuous threaded stud bolt with a fixed thread length
- Tap ends stud bolt – with uneven threads on both ends and a non-threaded center.
- Double-end stud bolts – with threaded ends of equal length and a non-threaded center.
ASTM A153 The ASTM A153 specification covers zinc coating (hot-dip) on iron and steel hardware. See the below chart for the different classes covered under A153. A newer and more fastener-appropriate specification, designed to replace A153 Class C, approved in 2005 and covering the requirement for hot-dip galvanizing bolts, screws, nuts, washers and other threaded fasteners is ASTM F2329. It is slowly becoming more widely used and referenced, but many publications and technical manuals are not revised on a regular basis, so it may still be a while before F2329 is widely adopted. ASTM A123 is a related hot-dip galvanizing specification covering iron and steel products made from rolled and pressed shapes, castings, plates, bars, and strips. The equivalent AASHTO specification to ASTM A153 is AASHTO M232.
ASTM F2329/F2329M specification covers the requirements for hot-dip zinc coating applied to carbon steel and alloy steel bolts, screws, washers, nuts, and special threaded fasteners. It also provides for minor coating repairs. Nails and rivets are not included in this specification.
It is intended to be applicable to fasteners that are centrifuged or otherwise handled to remove excess galvanizing bath metal (free zinc). The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
ASTM A193 Grade B7 Specification for high tensile bolts, screws, stud bolts, threaded rods, anchor bolts and other externally threaded fasteners, made from chromium-molybdenum alloy steel.
ASTM A193 Grade B7 is a standard material specification for chromium-molybdenum alloy steel fasteners for use in high tensile, high temperature and special purpose applications. Grade B7 is a heat-treated chromium-molybdenum alloy steel with minimum tensile requirement of 100 ksi, yield of 75 ksi and maximum hardness of 35 HRC. ASTM A193 specification covers requirements for chemical composition, mechanical properties, hardness, heat-treatment, recommended nuts-washers for Grade B7 fasteners. ASTM A193 Grade B7 is the most widely fastener specifications, commonly found in bolting or piping, pressure vessels, valves, flanges and fittings.
ASTM A193 Grade B7 Chemical Composition
| Element | Alloy Steel |
|---|---|
| Chromium Molybdenum SteelA | |
| CompositionB, % | |
| Carbon | 0.37 – 0.49C |
| Manganese | 0.65 – 1.10 |
| Phosphorus | 0.035 max |
| Sulfur | 0.040 max |
| Silicon | 0.15 – 0.35 |
| Chromium | 0.75 – 1.20 |
| Molybdenum | 0.15 – 0.25 |
A: Typical steel compositions used for this grade include 4140, 4142, 4145, 4140H, 4142H, and 4145H.
B: The intentional addition of Bi, Se, Te, and Pb is not permitted.
C: For bar sizes over 31⁄2 in. [90 mm], inclusive, the carbon content may be 0.50 %, max.
Mechanical Properties
| Diameter, inch. | Tensile Strength, min, ksi |
Yield Strength, min, 0.2% offset, ksi |
Elongation in 4D, min, % |
Reduction of Area, min, % |
Hardness, max |
|---|---|---|---|---|---|
| 2-1⁄2 and under | 125 | 105 | 16 | 50 | 321 HBW or 35 HRC |
| over 2-1⁄2 to 4, inclusive | 115 | 95 | 16 | 50 | 321 HBW or 35 HRC |
| over 4 to 7, inclusive | 100 | 75 | 18 | 50 | 321 HBW or 35 HRC |
Heat Treatment: Quenched & Tempered at 1100º F minimum.
Recommended Nuts & Washers
| Nut Specification | Washer Specification |
|---|---|
| ASTM A194 Grade 2H OR ASTM A194 Grade 2HM | ASTM F436 |
How to order our Stud bolt?
STUD BOLT: 5/8″ x 90 mm LONG ASTM A193-B7 W/2 HH NUTS ASTM A194-2H Hot Dip galvanized Quantity 50 Each
