Stud Bolt ASTM A193/A194 Zinc Plated Bichromated Plated Flange Fastener for Flange

• Customization: Available
• Material: Stainless Steel
• Type: Round Head
• Model NO.: SBN-051
• Connection: Common Bolt
• Head Style: Round
• Standard: DIN, ANSI, GB, JIS, BSW, ASME, ISO, Hg
• 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: 1/4"-4"
• Trademark: Qishine
• Origin: China
• HS Code: 7318159090
• Package Size: 20.00cm * 12.00cm * 12.00cm
• Package Gross Weight: 12.000kg

Product Description

Company Profile

Certifications

 

Stud Bolt and Nuts

A193 B7 Stud Bolt is a bolt with threads on both ends that engineered to be screwed into a fixed part at one end, and to receive a nut on the other end. In Petroleum or Chemical industry, they are mainly used for flange connection, so stud bolt used with two nuts on either side is the most common combination which replaces bolt and nut assembly.

As is well known, there are many types of Stud Bolts, and the type for flange connection is called flange stud bolts, which has a fully threaded end with with a cavity. The theoretical length is measured the thread. Continuous threaded stud bolt is very similar to it, except no chambered ends.


 

 

 

ASTM A193 Stud Bolts: Chemical Composition

The ASTM A193/A194 zinc-plated and bichromate-plated stud bolt is a specialized fastener designed to connect flanges in industrial applications.

 

Compliant with ASTM A193 and A194 standards, it meets requirements for high-strength, heat-treated alloy steel studs and nuts-making it suitable for high-pressure and high-temperature service. The dual plating (zinc and bichromate) enhances corrosion resistance, enabling reliable performance in harsh environments (e.g., exposure to moisture, chemicals, or industrial contaminants).

 

Structurally, the stud bolt is a double-ended threaded rod, with thread sizes and lengths tailored to specific applications. Paired with a nut (conforming to ASTM A194), it is tightened to create a secure flange connection.

 

Compared to bolts or screws, stud bolts offer distinct advantages in flange connections:

 

• Uniform load distribution: Reduces uneven pressure on gaskets, minimizing leaks and gasket failure.
• Ease of maintenance: Simplifies disassembly and reassembly, streamlining repairs and inspections.

 

Overall, this stud bolt is a reliable, durable solution for high-pressure, high-temperature flange connections. Its compliance with ASTM standards, dual plating for corrosion resistance, and practical design make it ideal for industrial settings requiring long-term performance and ease of maintenance.

 

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