Stud Bolts
No Head, Stable Heavy Load Connection.
Forged Stud Bolts, Zero Loose Failure.
Factory Custom, Fit All Flange Scenes.
Sinsun Stud Bolts – Double-End Threaded Flange Bolting for ASME B16.5 B7 / B8 / B16 & API Pressure Piping Systems
We supply forged stud bolts (double-end threaded rods / fully threaded flange studs) in Grade B7, B7M, B8, B8M & B16, with matching A194 nuts. From oil and gas pipeline flanges to petrochemical towers and power plant pressure vessels, each stud bolt meets ASME B16.5, ASTM A193, and NACE MR0175. Request traceable mill certificates with your bulk flange bolting order today.
Get a Quick QouteSinsun Stud Bolts | Product Overview & Core Advantages
Stud bolts, also known as threaded studs or studding fasteners, are headless metal fasteners that are threaded on one or both ends. Industrial markets know this product by different names. In European factories, it’s called bolts with thread sans tête; among Spanish industrial clients, it is known by pernos roscados sin cabeza, and in engineering circles, it’s also known as flange stud bolts. Headless studs are unlike standard hex bolts in that they focus on embedded assembly and provide precision locking for heavy-load mechanical and pipeline connection systems.
Sinsun, as a professional stud bolt manufacturer, builds differentiated product competitiveness through refined material matching and precision machining. Most common suppliers can only offer finished studs with one mechanical performance with a fixed standard. We strictly classify raw materials and heat treatment processes according to high temperature, high pressure and vibration intensity. All our stud bolts are manufactured to ASTM, DIN and API industrial standards to ensure uniform thread precision and structural toughness.
Global engineering buyers have pain points such as thread galling, shank deformation and poor fatigue resistance from low-quality stud bolts. Industry problems are handled by integral forging with secondary precision thread trimming. Our mainstream double end stud bolts, continuous thread stud bolts and tapping end stud bolts demonstrate stable connection performance under long term dynamic load and extreme temperature change. Besides, we also provide non-standard size and strength customization to satisfy personalized industrial project demands.
Double End Stud Bolts
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Stainless Steel Stud Bolts
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Fully Threaded Stud Bolts
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Tap-End Stud Bolts
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Threaded Rods
Send inquiry Now| Nominal Pipe Size (NPS) | Pressure Class | Bolt Diameter (UNC) | Number of Bolts | Approx. Stud Bolt Length (in/mm) – RF Flanges |
| 2″ | 150 | 5/8″ | 8 | 4.00″ (102 mm) |
| 2″ | 300 | 5/8″ | 8 | 5.00″ (127 mm) |
| 2″ | 600 | 5/8″ | 8 | 5.50″ (140 mm) |
| 3″ | 150 | 5/8″ | 8 | 4.50″ (114 mm) |
| 3″ | 300 | 3/4″ | 8 | 5.75″ (146 mm) |
| 3″ | 600 | 3/4″ | 8 | 6.25″ (159 mm) |
| 4″ | 150 | 5/8″ | 8 | 5.00″ (127 mm) |
| 4″ | 300 | 3/4″ | 8 | 6.25″ (159 mm) |
| 4″ | 600 | 7/8″ | 8 | 6.75″ (171 mm) |
| 6″ | 150 | 3/4″ | 8 | 5.50″ (140 mm) |
| 6″ | 300 | 7/8″ | 12 | 7.00″ (178 mm) |
| 6″ | 600 | 1″ | 12 | 8.25″ (210 mm) |
| 8″ | 150 | 3/4″ | 8 | 6.00″ (152 mm) |
| 8″ | 300 | 7/8″ | 12 | 7.50″ (191 mm) |
| 8″ | 600 | 1-1/8″ | 12 | 9.25″ (235 mm) |
| 10″ | 150 | 7/8″ | 12 | 6.25″ (159 mm) |
| 10″ | 300 | 1″ | 16 | 8.50″ (216 mm) |
| 10″ | 600 | 1-1/4″ | 16 | 10.00″ (254 mm) |
| 12″ | 150 | 7/8″ | 12 | 6.50″ (165 mm) |
| 12″ | 300 | 1-1/8″ | 16 | 9.00″ (229 mm) |
| 12″ | 600 | 1-1/4″ | 16 | 10.50″ (267 mm) |
| 14″ | 150 | 1″ | 12 | 7.00″ (178 mm) |
| 14″ | 300 | 1-1/8″ | 20 | 9.75″ (248 mm) |
| 14″ | 600 | 1-1/2″ | 20 | 11.50″ (292 mm) |
| 16″ | 150 | 1″ | 16 | 7.25″ (184 mm) |
| 16″ | 300 | 1-1/4″ | 20 | 10.25″ (260 mm) |
| 16″ | 600 | 1-1/2″ | 20 | 12.00″ (305 mm) |
*Source: ASME B16.5 Table E-1. Actual stud bolt length depends on flange type (WN, SO, Blind), gasket thickness, and washer usage. We recommend cross-checking against the project’s spec sheet before ordering
Meta Description
View Sinsun stud bolts technical parameters including materials, strength grades, standards and surface treatments to support industrial heavy-load connection projects.
Product Aliases
Threaded studs, flange stud bolts, headless stud fasteners, studding bolts.
Main Materials
Carbon steel, alloy steel, 304/316 stainless steel.
Strength Grades
4.8, 8.8, 10.9, 12.9, B7, B16 high-temperature grade.
Surface Treatment
Plain finish, zinc plating, hot-dip galvanized, black oxide.
Compliant Standards
ASTM A193, ASTM A320, DIN938, DIN939, API 20E/20F.
Thread Precision
ISO 6g high-precision thread, no galling or jamming.
Custom Service
Support custom length, thread pitch and special strength grades.
Petrochemical & Power Engineering
B7 and B16 high strength stud bolts are applicable to extreme temperature and high pressure working conditions in chemical and power plantsAs a result, these alloy studs resist thermal deformation and fatigue failure over the course of long-term cyclic operation. They firmly fix boiler flanges, pipeline joints and power equipment bases. These fasteners are used in critical energy industrial systems.
Pipeline & Flange Connection Projects
Double-end stud bolts are the standard mating fasteners for industrial pipeline flange assembly. The symmetrical double-thread structure provides balanced clamping force to prevent pipeline leakage. Continuous threaded stud bolts can be used where flange gaps are uneven. They are the universal accessory for the construction of water, gas and oil pipeline engineering.
Heavy Machinery & Equipment Assembly
Installation of mechanical equipment casings, pumps and valve components embedded in tap and stud bolts. The fixed single-end structure prevents equipment vibration from loosening the bolts. High strength grades withstand heavy mechanical loads and dynamic impact forces. They are effective at reducing equipment failure rates and extending equipment service life.
Marine & Offshore Industrial Facilities
316 stainless steel stud bolts are designed to withstand corrosion in severe marine salt fog and high humidity environments. The studs offer a stable connection performance for offshore platform equipment and ship pipeline fixings. Its anti-rust and anti-oxidation properties minimize maintenance costs in the future. They satisfy marine engineering projects' long-term durability requirements.
Construction & Structural Steel Engineering
Galvanized carbon steel stud bolts support steel structure connections and embedded fixing works in buildings. The anti-corrosion surface treatment is adapted to outdoor construction exposure. Full thread continuous studs can be cut to any length to suit complex structural assemblies. They increase construction flexibility and project stability.
Q: What are stud bolts used for?
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A: Stud bolts focus on flange connection, equipment embedding and heavy-load structural fixing for industrial engineering.
Q: Which stud bolt grade fits high-temperature scenarios?
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A: B7 and B16 alloy stud bolts deliver stable performance for high-temperature and high-pressure working environments.
Q: What are tap end stud bolts designed for?
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A: Tap end studs suit embedded fixed installation for precision equipment like pumps and valves.
Q: Can you customize non-standard stud bolt sizes?
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A: We customize exclusive lengths, thread pitches and strength grades for special project requirements.
Q: What is the difference between double end and continuous thread stud bolts?
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A: Double end studs have a plain middle shank; continuous thread studs feature full threads for flexible length adjustment.
Q: Are stainless steel stud bolts suitable for marine use?
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A: 316 stainless steel stud bolts provide excellent salt fog corrosion resistance for marine offshore projects.
Q: Do you provide API certified stud bolts?
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A: We manufacture standard API 20E/20F certified stud bolts for oilfield and petroleum projects.
Q: Why do flange projects prefer double end stud bolts?
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A: Their symmetric structure provides balanced clamping force to prevent pipeline flange leakage effectively.
Stud Bolt Installation & Selection Guide – Doing It Right
1.Choosing the Correct Stud Bolt Grade
There are two questions to answer before selecting a stud bolt: What is the operating temperature? Is the environment acidic (H2S present)?
General high temperature (to 450°C), non-sour: ASTM A193 Grade B7 studs + A194 Grade 2H nuts.
High temperature, sour service (H2S present): ASTM A193 Grade B7M + A194 Grade 2HM nuts (hardness not exceeding 22 HRC).
Low temperature (-40°C and below) / cryogenic: ASTM A320 Grade L7 or L7M (impact tested) + A194 Grade 4/7 nuts.
Very high temperature (greater than 450°C to 593°C): ASTM A193 Grade B16 + A194 Grade 2H, 4 or 7 nuts (depending upon temperature).
Corrosive / marine environments, limited strength: ASTM A193 B8 Class 1 (SS 304) or B8M Class 1 (SS 316) + A194 Grade 8/8M nuts.
General construction / low pressure: Threaded rods, ASTM A307 Grade A or B (low carbon steel).
2.Errors & Warnings Critical
You should never use standard hex bolts with ASME B16.5 flanges. Due to the reduced bearing surface, there will be uneven compression of the gasket resulting in leaks and code violations. Only heavy hex bolts or stud bolts are allowed.
Don't mix grades of stud and nut. A B7 stud should be used with a 2H nut, not a Grade 5 or Grade 8 nut. Threads can be stripped or fail early if the grade is wrong.
Do not over‑tighten beyond the specified torque. Over-torque damages stud threads, reduces the clamp load and permanently weakens the fastener.
Never install stud bolts dry. Stainless or coated fasteners will be more prone to galling, especially if the threads are dry. A false torque reading will result if the threads are dry.
The threads should be inspected for damage prior to assembly. One damaged thread can destroy the entire flange joint. There is no limit to how much damage a damaged thread can do to a flange joint.
| Thread Diameter | Recommended Torque (N·m) | Recommended Torque (ft·lbs) | Notes |
| 1/2″ – 13 UNC | 54 | 40 | Use cross‑pattern, two passes |
| 5/8″ – 11 UNC | 108 | 80 | |
| 3/4″ – 10 UNC | 183 | 135 | |
| 7/8″ – 9 UNC | 271 | 200 | |
| 1″ – 8 UNC | 400 | 295 | |
| 1-1/8″ – 8 UN | 530 | 390 | |
| 1-1/4″ – 8 UN | 745 | 550 | |
| 1-3/8″ – 8 UN | 950 | 700 | |
| 1-1/2″ – 8 UN | 1,220 | 900 | Hydraulic tensioning recommended |
| 1-3/4″ – 8 UN | 1,800 | 1,330 | |
| 2″ – 8 UN | 2,440 | 1,800 |
why sourcing your stud bolts from sinsun is the right move？
What does this mean for you and your procurement team? Traceability. 9. Regulatory compliance. No guesswork.
And we make cross-border shopping fun, not painful:
Pay in your own currency. Euro, Sterling, Australian Dollar, Brazilian Real, Turkish Lira, South African Rand, Indian Rupee, Thai Baht and many more. No hidden wire fees. No surprises on exchange rates.
Logistics door to door. Our in-house logistics team manages customs clearance, port coordination, inland freight and delivery to your warehouse. We deliver to any major port in the world.
Low MOQ of stock sizes. 100 pcs per stud bolt size. You can mix several diameters and grades in one container. Want a sample pack? We can send you 5-10 pieces of each size you specify, no big commitment required.
Engineers support you before ordering. Unsure whether B7 or B16 is the correct choice for your 550°C superheater header? Send us your process conditions and we’ll recommend the exact grade, finish and nut match. We don't guess, we check the ASTM tables and ASME codes.
Our B7M and L7M grades are NACE MR0175 sour service compliant as standard. Sour service is not a special request for us. It is part of our A193 production line routine. Hardness controlled, full documentation, no excuses. You get the material.
Most importantly we treat flange bolting as the safety critical application it is. When you request a quote, we’ll ask you about your operating temperature, pressure, gasket type, and whether the process stream contains H2S or chlorides. Then we’ll recommend the right grade, the right coating and the appropriate nut pairing, not the cheapest stock item we have on the shelf.
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