WHAT IS A STUD BOLT?
A Stud bolt, a fastener used for flanged connections, consists of one fully threaded steel rod and two heavy hexagonal steel nuts. The number, the length, the diameter of the required stud bolt depend on the flanges type, dimensions, and pressure rating.
Stud bolts are available in a multiple diameters and lengths combinations, metric and imperial, and in a variety of materials from carbon steel to alloy, stainless and nickel alloys (common grades are: ASTM A193 B7, L7, B8, B8M, B16, Alloy 20, Monel, Hastelloy, Inconel, 17-4PH, titanium, etc.). To increase the resistance to corrosion or aggressive conditions, stud bolts can also be coated with special materials (Zinc, Xylan, Xylar, Cadmium, Black Oxide, Teflon, etc).
STUD BOLT AND NUTS
The two components of a stud bolt set are, as discussed, the stud and the hexagonal steel nuts. Let’s take a closer look.
WHAT IS A STUD?
A stud is a threaded rod that is inserted into the holes of the mating flanges and then tightened, at both ends, by applying a specific torque to the steel nuts.
Stud length (OAL/FTF)
The length of the stud can be measured either as overall length (i.e., “OAL”) or as “first useable thread to first useable thread” (i.e., “FTF”). The FTF length can be calculated by subtracting a quarter of an inch to the OAL length, and it the standard stud length measurement for piping applications.
Flanges of different diameter and rating require stud of different lengths and diameters.
Stud thread pitch and thread series
The stud is threaded according to the specifications set by ASME B1.1.
The term “thread pitch” refers to the steepness of the angle of thread, which is measured in threads per inch.
The most used thread is the symmetrical thread pitch type with a “V-profile” (a 60-degree angle), as it is easier for the manufacturer to inspect compared to the non-symmetrical types.
Thread series relate to the diameter and pitch combinations, measured by the number of threads per inch (“TPI”) applied to a single diameter:
- Coarse thread series (UNC/UNRC): UNC is the most common type for screws, bolts, and nuts. Coarse threads are used for threads in low strength materials such as iron, mild steel, copper and softer alloy, aluminum, etc. The coarse thread is also more tolerant of adverse conditions and it facilitates quick assembly
- Fine thread series (UNF/UNRF): UNF is widely used for precision duties and when a higher tensile strength is required (vs. the coarse thread series)
- 8-Thread series (8UN) is the elective threading method for several ASTM standards including A193 B7, A193 B8/B8M, and A320. This series is widely used for diameters from one inch upwards
Stud bolts covered by the ASTM A193 or A320 Specifications use 8UN for all diameters 1” and above, which means that there are 8 threads per inch for these sizes. For any other material grade, the buyer shall specify the thread pitch unless it is given by the applicable ASTM norm.
Stud bolt length calculation formula
The length of stud bolts can be calculated with a simple formula which takes into consideration parameters such as free threads, the thickness of the nut and the flange, height of the raised face on the flange and the thickness of the gaskets applied on the flanges:
Stud Bolt Length (L) = 2 x (S + he + eb + i) + J
- “S“: free threads (1 to 2 pitch)
- “he“: nut thickness
- “eb“: flange thickness (with tolerance)
- “i“: height of raised face (for 150 and 300 flanges rating, the height of raised face is included in “eb” height)
- “J“: gasket thickness
NUTS FOR STUD BOLT
To fasten a stud, two heavy hex steel nuts have to be bolted at the opposite ends of the rod.
The stud and the steel nuts join perfectly due to the friction existing between their respective threads, by a slight stretching of the bolt, and the compression of the two joined parts.
In the past, steel nuts had a squared head. Nowadays, hexagonal head nuts (featuring 6 sides instead of 4) have fully replaced the older shape as they ensure quicker and more effective screwing on the stud.
Nuts for petrochemical applications are tightened to a specific torque using special torque wrenches. The mechanical strength of the nut material shall be compatible with the strength of the mated bolt.
STUD VS BOLT
A common question is what is the difference between stud and bolts? The answer is that a stud is a metal rod or shaft that features threads on both sides (as shown in the image above) and requires two heavy hexagonal nuts to be serrated; a bolt is a fastener with a “built-in” head nut at one side and that requires a single nut to be serrated.
Stud vs. bolt (stud on the left image, bolt on the right image)
STUD BOLT TORQUE CHART
Charts are for reference only and assume properly lubricated ASTM A193 B7 stud bolts with ASTM A194 2H.
TORQUE CHARTS FOR ASME B16.5 CLASS 150
|B16.5 Class 150 RF/ Ring Gaskets||B16.5 Class 150 FF/ Full Face Gaskets|
|Torque / Round (ft-lbs)||Stud Bolts Tighten Sequence||Torque / Round (ft-lbs)||Stud Bolts Tighten Sequence|
|1st||2nd||Final||Dwg/No.||Bolt Size||1st||2nd||Final||Dwg*/No.||Bolt Size|
TORQUE CHARTS FOR ASME B16.5 CLASS 300
|Flange Size||B16.5 Class 300 RF/ Ring Gaskets|
|Torque / Round (ft-lbs)||Stud Bolts Tighten Sequence*|
|1st||2nd||Final||Dwg/No.||Stud Bolts Size|
Stud bolt tightening sequence:
STUD BOLT DIMENSIONS (ASME B16.5)
|FLANGE 150#||FLANGE 300#||FLANGE 600#|
|NPS||# Stud Bolts||Stud Diameter||Stud Length||# Stud Bolts||Stud Diameter||Stud Length||# Stud Bolts||Stud Diameter||Stud Length|
|1/16 RF||RTJ||1/16 RF||RTJ||1/4 RF||RTJ|
All measures in inches – imperial
|FLANGE 900#||FLANGE 1500#||FLANGE 2500#|
|Nominal Pipe Size||# Stud Bolts||Stud Diameter||Stud Length||# Stud Bolts||Stud Diameter||Stud Length||# Stud Bolts||Stud Diameter||Stud Length|
|1/4 RF||RTJ||1/4 RF||RTJ||1/4 RF||RTJ|
STUD BOLTS PRICES
Click on the link below to estimate stud bolts prices for your projects:
- imperial stud bolts prices
- metric stud bolts prices
The tool estimates the price for metric and imperial stud bolts manufactured in Europe (mill and stock price) and in India/China (see prices under “Asian”). It provides budget prices for all stud bolts in multiple diameters and, lengths.
To get the price for a specific product, click on the link below, choose the relevant stud bolt type, the body material grade, the nominal size and download or print your budget price estimate. Our prices are based on the current market trends and on the LME prices for raw materials such as steel scrap, nickel, molybdenum, copper and, ferroalloys.
Even if our price estimates are reliable, prices shall always be double checked with stud bolts manufacturers and stockists before being used for firm offers to end users.
Besides stud bolts prices, our online tool estimates the prices of other piping materials such as pipes, flanges, valves, butt weld and forged fittings, flanges in various material grades and dimensions.
BUY AND SELL STUD BOLTS ONLINE!
If you buy stud bolts for flanges for your projects, you can browse the sales offers from reputable suppliers on Projectmaterials.com (manufacturers, stockists, and distributors), find the stud bolts and nuts you need and close the order online. Otherwise, you can post a request for quote (RFQ) and get offers from trustable stud bolts vendors.
If you are a manufacturer, stockist or distributor of stud bolts, you can sell them on Projectmaterials.com easily: simply list your A193 stud bolts for sale and receive orders or inquiries from international End Users, EPC contractors and traders. By listing your stud bolts on Projectmaterials.com, you increase your sales potential at no cost!
Senex, Jemena to accelerate Queensland Atlas coal seam gas project
on June 19, 2018 at 8:22 pm
Senex Energy and infrastructure operator Jemena have made an agreement to join forces to accelerate the proposed Atlas coal seam gas project in the Surat basin of southeast Queensland to deliver gas to the domestic market by late 2019. […]
Denson named Hunter Oil chief executive
on June 19, 2018 at 7:56 pm
Al H. Denson has been named chief executive officer of Hunter Oil Corp., Vancouver, BC. […]
Fitch: Defaults continue in US energy, despite higher oil prices
on June 19, 2018 at 7:49 pm
Defaults are still occurring in US energy despite higher oil prices, said Fitch Ratings, pointing specifically at exploration and production companies. In August 2016, the distress rate peaked with a 32.1% default rate for E&P companies. In January 2017 the default rate hit 19.7% for energy overall. […]
Court: Scotland opposes, didn’t ban fracing
on June 19, 2018 at 5:24 pm
Scotland has a government opposed to hydraulic fracturing but not a ban on the completion technique, the Court of Session in Edinburgh has ruled. Ineos Shale, which holds two petroleum exploration and development licenses between Glasgow and Edinburgh, welcomed the ruling even though it represented legal defeat. &nbs […]
Gulfport Energy updates SCOOP Woodford well results
on June 19, 2018 at 4:55 pm
Gulfport Energy Corp., Oklahoma City, has updated recent well results on its SCOOP Woodford assets in Oklahoma’s southeastern Anadarko basin. The SCOOP play mainly targets the Devonian to Mississippian Woodford shale.&nbs […]
Nigerian operator lets contract for new refinery
on June 19, 2018 at 4:20 pm
Waltersmith Petroman Oil subsidiary Waltersmith Refining & Petrochemical has let a contract to Velem—a joint venture of Lambert Electromec and VFuels—to build a 5,000-b/d modular refinery at Ibigwe, Nigeria.&nbs […]
Denbury sanctions Cedar Creek Anticline carbon dioxide development
on June 19, 2018 at 3:52 pm
Denbury Resources Inc., Plano, Tex., has sanctioned a carbon dioxide enhanced oil recovery project at Cedar Creek Anticline, which extends across Montana, North Dakota, and South Dakota. Denbury has interest in about 175,000 acres.&nbs […]
Al Jahraa development well has deep target
on June 19, 2018 at 3:22 pm
The Kuwait Energy Al Jahraa-6, the first of two development wells planned this year on the Abu Sennan license in Egypt’s Western Desert, also will test deeper-pool potential, reports Rockhopper Exploration PLC, a partner in the production-sharing contract.&nbs […]
Oxy, White Energy studying possible carbon-capture plant
on June 19, 2018 at 2:50 pm
Occidental Petroleum Corp. and White Energy agreed to evaluate the feasibility of a carbon capture, utilization, and storage project that would capture carbon dioxide at White Energy’s ethanol infrastructure in Hereford and Plainview, Tex. […]
Gritzfeldt named Crescent Point COO
on June 19, 2018 at 2:42 pm
Ryan Gritzfeldt has been named chief operating officer of Crescent Point Energy Corp., Calgary. He had been vice-president, marketing and innovation, and before that vice-president, engineering and business development east. […]
Publish your products free and attract buyers
Post your RFQs free and get proposals
Buy and sell without payment risks
Get instant quotes for sea, ground, air shipments
Stand out with a verified company profile
Build relations with buyers and sellers
- Jacketed Gasket for Exchangers, Pumps, Valves
- Nipoflange and Weldoflange
- Expanding and Reducing Flanges
- Best Piping Dictionary
- ASME B16.34 Pressure and Temperature Charts
- Stud Bolts Materials ASTM A193, A320, A453, A182
- Heavy Hex Nuts Dimensions ASME B18.2.2
- Stud Bolt Weight (Imperial and Metric)
- Stud Bolt Chart ASME B16.5
- Kammprofile Gasket (Grooved)
- Spiral Wound Gasket ASME B16.20
- Ring Joint Gasket R, RX and BX (Metal Gaskets)
- Non Asbestos Gasket for Flanges ASME B16.21
- Flange Gasket: Types and Top 5 Selection Criteria
- Threaded Flange Dimensions (EN 1092 Type 13)
- Weld Neck Flange Dimensions (EN 1092 Type 11)
- Blind Flange Dimensions (EN 1092 Type 05)
- Plate Flange Dimensions (EN 1092 Type 01)
- Flange Face Finish: Stock, Serrated, Smooth
- Raised, Flat, Ring Joint Face Flange (RF, FF, RTJ)
- Flange Bolt Chart ASME B16.5, EN 1092-1
- Flange Rating Chart
- Slip On Flange Dimensions ASME B16.5
- Blind Flange Dimensions ASME B16.5
- Welding Neck Flange Dimensions ASME B16.5
- Carbon Steel Flange ASTM A105, A350, A694
- Flange Spade and Ring Spacer for Pipelines
- Spectable Blind for Pipeline ASME B16.48
- Swivel Flange for Subsea and Large Pipes
- Stub End for Cost Effective Flanged Joints
- Orifice Flange ASME B16.36
- The 7 Types of Flanges Explained
- What is a Pipe Flange?
- Valve End Types: Flanged, Socket Weld and Threaded