ASTM A320 L7 Stud Bolt ASME B18.2.1 Fastener

• Customization: Available
• Material: Carbon Steel
• Type: Round Head
• Model NO.: SBN-011
• Connection: Common Bolt
• Head Style: Round
• Standard: DIN, ANSI, GB, JIS, BSW, ASME, ISO, Hg
• Grade: 10.9
• Application: Machinery, Chemical Industry, Environmental, Building, B16.5 Flanges Connection
• Finish: Black
• Surface Treatment: Phosphating
• 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: 1-1/2" X 160mm
• Trademark: Qishine
• Origin: China
• HS Code: 7318159090
• Package Size: 30.00cm * 30.00cm * 35.00cm
• Package Gross Weight: 110.000kg

Product Description

Company Profile

ABOUT US

Xiamen Qishine Industry Co., Ltd. is a Chinese company established in 2013. We are a leading fabrication services provider in industries such as Oil & Gas, Petroleum, Marine, Oilfield, Mining, and Heavy Industry, specifically for pipeline construction and maintenance.

Qishine is ideal choice for EPC companies and project contractors. Our company specializes in supplying a range of products including Fasteners, Flanges, Gaskets, Fittings, Valves, Pipes and Piping Spare Parts. Our products are API, CE, TUV and ISO certified.   Products are widely used on oil rigs, new nuclear power plant, Chemical and Heavy Industry.

Qishine is proud as being a premium product supplier who works closely with our clients to achieve the best possible results. We have an experienced team, skilled labor force, and advanced facilities to ensure safe and efficient project completion, meeting deadlines and budget requirements.

Qishine is ideal choice for EPC companies and project contractors.

Product Description

Engineered for high-pressure, high-temperature (HPHT) environments, our ASTM A320 L7 Stud Bolt meets the rigorous standards of ASME B18.2.1-delivering uncompromising strength, corrosion resistance, and dimensional precision for industrial critical applications.

Crafted from chrome-molybdenum alloy steel (AISI 4140/4142), this stud bolt undergoes quenching and tempering to achieve a minimum tensile strength of 120 ksi (827 MPa) and yield strength of 95 ksi (655 MPa). Its black oxide or zinc plating finish enhances resistance to oxidation and harsh chemicals, making it ideal for oil & gas pipelines, petrochemical reactors, power generation turbines, and pressure vessels.

Compliant with ASME B18.2.1 dimensional specifications, each stud bolt features uniform threading (UNC/UNF or metric) with Class 2A fit, ensuring seamless compatibility with nuts and flanges. The fully threaded or partially threaded design (per customer request) provides flexible installation, while strict quality control-including magnetic particle inspection (MPI) and ultrasonic testing (UT)-eliminates defects like cracks or inclusions.

Whether used in offshore platforms, refineries, or nuclear facilities, our ASTM A320 L7 Stud Bolt guarantees long-term reliability under extreme conditions. We offer custom lengths (1/2" to 24") and diameters (1/4" to 4") to meet project requirements, with full traceability documentation (heat numbers, material certificates) provided for every order.

Choose a fastener built to exceed industry standards-trust our ASTM A320 L7 Stud Bolt for safety, durability, and performance you can depend on.

 

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