Fasteners
June 10, 2026
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- Petrofast Middle East: Fastening Solutions with Experience
- Hamriya Free Zone, Sharjah, UAE
Stud bolt types make all the difference in holding flanges, pipelines and pressure vessels together. Choose wrong and you could be facing leaks, failures and costly downtime. The right one keeps your system safe for years.
Every day thousands of critical joints in industries such as oil and gas, power generation and construction across the UAE and wider GCC region are being secured with stud bolt fasteners. But not all stud bolts are equal.
This guide covers the most common stud bolt types, as well as the standards they are made to, the materials used to make them and where each is best used.
There are several types of stud bolts. Each one is designed for a specific job. Some are used for structural or mechanical applications. Knowing the difference is helpful in choosing the right fastener for the right job.
Each of these serves a different purpose. Petrofast Middle East FZC stocks all of these in a wide variety of materials, grades and finishes. They are available as per ASTM A193/A193M, ASTM A320/A320M, ISO 3506-1 and ISO 898-1 standards.
Threaded stud bolts are one of the most common fasteners in industrial plants. They are used where a bolt head is impractical or where there is no room for a bolt head. The stud is screwed into a hole on one side and a nut is used on the other side.
Petrofast Middle East FZC provides threaded stud bolts in the following grades of material:
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Standard
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Material Grades Supported
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B7, B7M, B16, B8, B8M, B8T, B8C, B8MCuLN
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L7, L7M, L43, B8 (Class 1 & 2), B8M (Class 1 & 2)
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A2-70, A4-70, A4L-70, A4-80, A4L-80
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Property Class 4.6, 8.8, 10.9, 12.9
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Coatings available: Polytetrafluoroethylene (PTFE) in various colours, Hot Dip Galvanized (HDG), Electro Zinc Plated, Yellow Passivated , Black , Phosphate , Electroless Nickel Plated (ENP) and Zinc Nickel Plated . The coating range makes these threaded stud bolts suitable for corrosive and offshore environments all over the UAE.
Flange stud bolts are used to connect pipe flanges. They are always used in pairs with heavy hex nuts on both ends. These are one of the most critical fasteners in any piping system.
Stud Bolts for Flanges are used in UAE and GCC refineries, gas processing plants, water treatment facilities and offshore platforms. The correct stud bolt must be the same as the flange class, pressure rating and temperature range.
Petrofast Middle East FZC supplies flange stud bolts UAE operations depend on, following ASME B16.5 flange standards. Stud Bolts for Flanges are being used in UAE and GCC refineries, gas processing plants, water treatment facilities and offshore platforms. The proper stud bolt shall be of the same flange class, pressure class, and temperature range.
B7 stud bolts are the most widely used grade in the oil and gas industry. They are made from chromium-molybdenum alloy steel and heat-treated to give them excellent strength and toughness.
According to ASTM A193/A193M, the mechanical requirements for B7 are:
Heavy duty stud bolts are designed for extreme loads. They are used in structural bolting, bridge construction, heavy machinery and large diameter pipeline joints. These bolts must be able to carry high clamping loads without any stretching or loosening.
Surface Finishes are Black, Hot Dip Galvanized (HDG) and Electro Zinc Plated. For structural steel projects in the UAE construction, these high tensile stud bolts meet both inch and metric dimensional requirements.
Stainless Steel Stud Bolts and Carbon Steel Stud Bolts are used for different purposes. It depends on the environment in which it will work, the temperature and the type of fluid or gas with which it will deal.
Petrofast Middle East FZC carries stainless grades ASTM A276 SS304, SS304L, SS316, SS316L, 310, 410 and duplex grades S31803, S32205, S32750 and S32760. gives 75 ksi (515 MPa) tensile strength and 30 ksi (205 MPa) yield. provides the same strength with better resistance to chloride attack. Stainless steel stud bolts UAE applications include desalination plants, offshore rigs, coastal industrial facilities and chemical processing units. The addition of Molybdenum in Grade 316 (Cr 16-18%, Ni 10-14%, Mo 2.0-3.0%) gives the advantage in salt water and acidic conditions.
Carbon steel stud bolts are the standard choice for general industrial use. They provide greater tensile strength than most grades of stainless steels and at less cost. Grades such as B7 (alloy steel) and B16 (chromium molybdenum vanadium) are in wide application up to 450°C and above in high temperature applications.
For carbon steel studs that require corrosion protection, Petrofast Middle East FZC provides coating with PTFE, HDG or ENP in its in-house PTFE coating plant. This is a key advantage of working with a manufacturer who controls the full production chain.
The table below compares the main stud bolt types by material, application, grade, and use.
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Stud Bolt Type
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Material
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Application
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Strength Grade
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Common Use
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Fully Threaded Stud Bolt
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Alloy Steel (B7)
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Pipe Flanges, Pressure Vessels
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ASTM A193 B7
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Oil & Gas, Petrochemical Plants
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Tap End Stud Bolt
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Carbon Steel / Alloy Steel
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Machine Parts, Gear Boxes
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ASTM A193 B7M
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Marine, Heavy Machinery
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Continuous Thread Stud
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Carbon Steel / Stainless
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Structural Anchoring, Civil Works
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ISO 898-1 CL 4.6 – 12.9
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Construction, UAE Infrastructure
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B16 High Temp Stud Bolt
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Chromium Molybdenum Steel
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High Temperature Pipelines
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ASTM A193 B16
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Power Plants, Steam Lines
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Stainless Steel Stud Bolt
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SS304, SS316, SS316L
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Corrosive Environments, Offshore
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ASTM A276
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Offshore UAE, Desalination
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Duplex / Super Duplex Stud
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S31803, S32205, S32750, S32760
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Highly Corrosive Pipelines
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ASTM A276
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LNG Terminals, Subsea UAE
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There are a lot of different sectors that use industrial stud bolt types. These are the key industries for which these fasteners are a must, especially in the UAE and GCC region.
The largest end-use sector. B7 and B16 ASTM stud bolts are used in wellheads, pipelines, pressure vessels, heat exchangers and flange assemblies. PTFE coated B7 studs are important for Dubai and UAE projects because they simplify assembly and provide corrosion protection for flange stud bolts.
B16 studs are needed for high temperature service in refineries. These are manufactured from chromium-molybdenum-vanadium steel and will perform well where standard B7’s performance begins to diminish. B16 has the addition of vanadium to improve creep resistance.
B7 and B16 ASTM stud bolts are used in large quantities in turbines, boilers and steam lines. They have to hold tight flanged joints through continuous thermal cycling.
Anchor bolts and foundation bolts are a common sight on UAE construction sites. Petrofast Middle East FZC produces them according to ASTM F1554 (Grades 36, 55 and 105), EN10025-2 (S275JR and S355JR) and ISO 898-1 (Grades 4.6, 8.8 and 10.9).
UAE Plants Use Stainless Steel and Duplex Stud Bolt Fasteners The chloride rich environment requires duplex grades of at least S31803 or S32205.
Applications are specified for marine & offshore super duplex grades S32750 and S32760. They have a minimum tensile of 760–860 MPa and excellent resistance to pitting and crevice corrosion.
Choosing the right stud bolt comes down to four key factors: operating conditions, material compatibility, relevant standards, and coating requirements.
Specify the service conditions. Check Pressure class, temperature range, and type of fluid or gas A flange joint on a 600 lb class steam line requires different studs than a 150 lb water flange.
Match the material with the environment. B7 stud bolts can be used for general service up to 400°C. For extremely high temperatures, use B16. For corrosive or marine services, select stainless or duplex grades. Use L7 or L7M for cryogenic service.
Choose the right standard. Most of the oil and gas projects in UAE use ASTM A193 for stud bolts and ASTM A194 for nuts. ISO 898-1 and ISO 3506-1 are used in European specifications.
Define finish and coating. HDG or PTFE coating adds corrosion life for outdoor or subsea applications. Food or pharmaceutical grade might require an ENP or electropolished finish.
If you are not sure, reach out to a stud bolt supplier UAE teams trust. Petrofast Middle East FZC’s engineers can assist you to specify the right grade, size and coating for your project.
Stud bolts are very tiny parts. But they support systems that move millions of barrels of oil, billions of litres of water and megawatts of power every day. A wrong grade or missed coating spec can mean a flange leak, an unplanned shutdown or worse.
Petrofast Middle East FZC has been a trusted stud bolt supplier for UAE projects for more than 20 years. With a 10,000 sq. metre manufacturing facility in Hamriyah Free Zone, Sharjah, UAE, they manufacture and supply a complete range of stud bolt fasteners to ASTM, ISO, and DIN standards.
Every product comes with full traceability, material test reports (MTRs), and dimensional inspection records. The in-house PTFE coating plant, shot blasting machine, laser marking machine and Universal Testing Machine ensures that quality is controlled at every step from raw material to finished product.
Whether you need B7 studs for a flanged pipeline, duplex studs for an offshore riser or structural bolts for a steel frame in Abu Dhabi, Petrofast Middle East FZC can provide exactly what you need, in the grade you specify, with the coating you require, on the schedule your project demands.
Email your material requisition or engineering drawings to info@petrofastme.com or call +971 55 609 0841 to discuss your technical specifications with our team.
A stud bolt is a straight metal rod with ridges (threads) all the way around it from end to end. There is no fixed head. A standard bolt has a six-sided head on one end. Stud bolts are good for holding pipe joints together. You can put a nut on each side and tighten it.
The most commonly used is the B7 bolt. It’s put in a special hot oven to make it super strong and tough, which helps it hold heavy-duty pipeline parts securely together.
For ordinary daily work B7 bolts are used with special tough 2H heavy nuts.
Yes. Grades such as B8M and super duplex are widely used in the ocean. They do a great job keeping the rust from salt water and tough beach weather.
Petrofast Middle East FZC provides different protective options like colorful PTFE plastic, hot zinc baths, shiny zinc plating, yellow coating, phosphate and nickel layers to protect your bolts outdoor.
