A193 B16 Stud Bolt
ASTM A193 B16 Stud Bolts are alloy steel threaded studs designed for bolted joints exposed to elevated temperatures and demanding service conditions. Manufactured from heat-treated alloy steel, B16 stud bolts provide the strength and temperature resistance required for connections where conventional carbon steel fasteners may not be suitable.
The fully threaded or double-end stud configuration allows the bolt to be installed with compatible nuts on the mating components, making it practical for flanged connections, pressure equipment, valves, piping systems, and other heavy-duty bolted joints. The stud design also allows the fastening assembly to be tightened and serviced without requiring access for turning a conventional bolt head. ASTM A193 B16 Stud Bolts are commonly selected for power generation, petrochemical, refinery, and high-temperature process equipment. Selection should consider the stud diameter, thread configuration, length, nut compatibility, operating temperature, and required mechanical properties to ensure the complete bolting assembly meets the service requirements.
Specification:
ASTM A193 B16 Stud Bolts are manufactured from chromium-molybdenum-vanadium alloy steel and supplied in accordance with the applicable requirements of ASTM A193/A193M. The B16 grade is intended for bolting applications where elevated-temperature mechanical properties and resistance to demanding service conditions are required. Heat treatment and mechanical properties are controlled according to the applicable specification and product size.
The stud bolts can be supplied in different thread configurations and lengths to suit the mating flange, valve, pressure vessel, or piping connection. Thread dimensions should be matched with the corresponding nuts, while the selected stud diameter, length, material condition, and surface finish should be verified according to the application requirements.
| Item | Specification |
|---|---|
| Standard | ASTM A193/A193M |
| Grade | B16 |
| Product Type | Stud Bolt/Threaded Stud |
| Material | Alloy Steel |
| Diameter | 1/4″ – 4″ |
| Dimension Standard | ASME B18.31.2 |
| Thread | UNC/UNF/8UN |
| Tension Strength | 125 KSI |
| Thread Form | Unified 60° Thread |
| Surface treatment | Black Oxidation,Zinc Plated, Hot Dip Galvanized |
| Compatible Nuts | A194 GR.4/GR7 Nuts |
Chemical Composition:
ASTM A193 Grade B16 Stud Bolts are manufactured from chromium-molybdenum-vanadium alloy steel, with the chemical composition controlled to provide the material characteristics required for elevated-temperature bolting. The alloying elements, particularly chromium and molybdenum, contribute to strength and resistance to degradation at elevated temperatures, while vanadium supports the required heat-treatment response and mechanical properties. Chemical composition is controlled according to the applicable ASTM A193/A193M requirements to ensure consistent material quality.
| Property class | Material and heat treatment | Chemical composition limits (cast analysis, %) a | ||||||
|---|---|---|---|---|---|---|---|---|
| A193 B16 | Alloy steel, AISI 4140/4142 quenched and tempered | Carbon | Manganese | Phosphorus, max | Sulfur, max | Silicon | Chromium | Molybdenum |
| 0.36 - 0.47% | 0.45 - 0.7% | 0.035% | 0.040% | 0.15 - 0.35% | 0.80 - 1.15% | 0.5-0.65% | ||
Mechanical and physical properties:
The mechanical properties of ASTM A193 Grade B16 Stud Bolts are established according to ASTM A193/A193M and are achieved through the specified heat-treatment process. The requirements cover key properties such as tensile strength, yield strength, elongation, reduction of area, and hardness. These properties determine the stud bolt’s ability to withstand tensile loading and maintain reliable performance under demanding temperature and pressure conditions. The applicable requirements should be verified according to the stud diameter and product specification.
| Grade | Size | Tensile ksi, min | Yield, ksi, min | Elong, %, min | RA % min | HBW | Rockwell |
|---|---|---|---|---|---|---|---|
| B16 | Up to 2-1/2 | 125 | 105 | 18 | 50 | 321 max | 35 HRC max |
| 2-5/8 - 4 | 110 | 95 | 17 | 45 | |||
| 4-1/8 - 7 | 100 | 85 | 16 | 45 |
Application of A193 B16 Stud Bolts:
Refinery & Petrochemical Equipment
ASTM A193 B16 Stud Bolts are widely used in refinery and petrochemical equipment, including process piping, pressure vessels, heat exchangers, valves, and flanged connections. Their chromium-molybdenum-vanadium alloy steel construction is suitable for bolted joints exposed to elevated temperatures and demanding operating conditions.
Power Generation & Steam Systems
B16 Stud Bolts are suitable for power generation equipment, steam piping, boilers, turbines, and high-temperature pressure systems where reliable bolting performance is required under elevated operating temperatures. The stud-and-nut configuration also allows secure tightening of heavy-duty flange connections.
Pressure Equipment & High-Temperature Flanges
These stud bolts are used for pressure vessels, pumps, valves, high-temperature flanges, and process equipment where the bolting assembly must withstand significant mechanical and thermal loads. They can be supplied in different diameters, lengths, thread configurations, and surface finishes to suit specific connection requirements.