ASME B18.2.1 Full Thread Rod ASTM A193 B7 Stud Bolt Flange Fastener

• Customization: Available
• Material: Carbon Steel
• Type: Round Head
• Model NO.: SBN-017
• Connection: Common Bolt
• Head Style: Round
• Standard: DIN, ANSI, GB, JIS, BSW, ASME, ISO, Hg
• Grade: 8.8
• Application: Machinery, Chemical Industry, Environmental, Building, B16.5 Flanges Connection
• Finish: Black
• Surface Treatment: Black
• Delivery: 2-4 Weeks
• Thread: Full Thread, Unc, Unf
• Length: According to Client's Requirement
• Size Range: M6-M100, 1/4"- 4"
• Transport Package: Plywood Cases/Wooden Boxes
• Specification: 3/4" x 80mm
• Trademark: Qishine
• Origin: China
• HS Code: 7318159090
• Package Size: 35.00cm * 30.00cm * 30.00cm
• Package Gross Weight: 110.000kg

Product Description

Company Profile

Stud Bolt and Nuts

Engineered for heavy-duty flange applications, our ASTM A193 B7 Stud Bolt with ASME B18.2.1-compliant full thread rod delivers exceptional strength, heat resistance, and reliability-ideal for critical industrial systems where safety and performance non-negotiable.

Crafted from high-grade chromium-molybdenum alloy steel, this stud bolt undergoes precision quenching and tempering to achieve a minimum tensile strength of 120 ksi (827 MPa) and yield strength of 95 ksi (655 MPa). It excels in high-temperature (up to 1000°F/538°C) and high-pressure (HPHT) environments, outperforming standard carbon steel fasteners in refineries, power plants, chemical processing facilities, and oil & gas pipelines.

The full thread rod design-strictly aligned with ASME B18.2.1 dimensional standards-ensures maximum engagement with flanges and nuts, eliminating looseness under vibration. Threads feature Class 2A fit (UNC/UNF or metric options) for seamless installation, while optional finishes (hot-dip galvanizing, zinc plating, or black oxide) boost corrosion resistance against moisture, chemicals, and harsh weather.

Every unit undergoes rigorous quality control: magnetic particle inspection (MPI) detects surface cracks, and ultrasonic testing (UT) verifies internal integrity. We offer custom lengths (1" to 36") and diameters (1/4" to 4") to match unique flange specifications, with full traceability documentation (heat numbers, material test reports) included for regulatory compliance.

Trust our ASTM A193 B7 Stud Bolt with ASME B18.2.1 full thread rod to secure your critical flange connections-backed by consistent performance, durability, and industry-leading quality.

 

Certifications

 

As we know that Stud Bolts have many categories, the type for flange connection is called flange stud bolts, which has fully thread with chambered ends. The theoretical length is measured the thread. Continuous threaded stud bolt is very similar to it, except no chambered ends.



Stud Bolt Materials

The most common materials for stud bolts (for flanges) are ASTM A193 (grade B7, B8, B8M, B8T), ASTM A453 (grade 660), ASTM A320 (grade L7, L7M), and ASTM A182 (duplex and super duplex bolting). For aggressive fluids and environments, stud bolts can be coated with Xylan/PTFE, Zinc and other materials.
 

ASTM A193 Stud Bolts: Chemical Composition

Physical Element	ASTM A193 grade B7 (AISI 4140)	ASTM A193 grade B8 (AISI 304)	ASTM A193 grade B8M (AISI 316)
Carbon	0.38 - 0.48%	0.08% max	0.08% max
Manganese	0.75 - 1.00%	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	0.80 - 1.10%	18.0 - 20.0%	16.0 - 18.0%
Nickel	absent	8.0 - 11.0%	10.0 - 14.0%
Molybdenum	0.15 - 0.25%	absent	2.00 - 3.00%

ASTM A193 Stud Bolts: Mechanical Properties

ASTM A193	Size	Min Tensile Strength (KSI)	Min Yield Strength (KSI)	Min Elongation (%)	RA % min	Max HBW	Max HRC
ASTM A193 grade B7	Up to 2-1/2	125	105	16	50	321	35
	2-5/8 - 4	115	95	16	50
	4-1/8 - 7	100	75	18	50
ASTM A193 grade B8 Class 1	All	75	30	30	50	223	35
ASTM A193 grade B8M Class 1	All	75	30	30	50	223	96
ASTM A193 grade B8 Class 2	Up to 3/4	125	100	12	35	321	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
ASTM A193 grade B8M Class 2	Up to 3/4	110	95	15	45	321	35
	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

 

The material chosen for the threaded stud and the hex nuts should be compatible. Materials for bolting sets shall be selected based on the process's working temperatures, as shown in the table below:

	TEMPERATURE °C ( °F )
STUD BOLTS MATERIALS	MIN.	MAX.
CARBON STEEL	-29 (-20)	300 (572)
A193 B7, L7	-73 (-100)	400 (752)
A193 B6	0 (32)	500 (932)
A193 B8	-200 (-325)	575 (1067)
A193 B16	0 (32)	520 (968)
A193 B17B	-29 (-20)	650 (1202)
A913 Inconel 718	0 (32)	750 (1382)
A453 Gr. 660	-29 (20)	538 (1000)

 

ASTM A453 Stud Bolts for High-Temp. Service

ASTM A320 Stud Bolts for Low-Temp. Service

 

 Stud Bolts' Coating

Stud bolts can be coated to increase the resistance to corrosion. The most common types of coatings for stud bolts are listed below:

• Electro zinc plating
• Electro cadmium plating
• Hot dip galvanizing
• PTFE Coating
• Phosphate coating
• Electroless nickel plating
• Zinc-nickel coating
• Aluminum coating
• Silver coating
• Zinc/Nickel by electrodeposition
• Xylan coating