RapidBoltGet a Quote
    Back to Products

    Stud Bolts Australia: Certified Kits for Flange Bolting

    Continuous thread and double-end stud bolts to ASTM A193, A320 and A453 in carbon, alloy, stainless, duplex and nickel alloy grades, supplied as complete kits with matching nuts and EN 10204 certification.

    Sleeved ASTM A193 B7 stud bolts with A194 2H nuts crated and tagged for a gas plant shutdown
    B7/2H stud bolt kits individually sleeved, crated and tagged by diameter for site handover
    EN 10204 3.1 Certified
    ISO 9001 Quality
    ASTM A193 B7 stud bolts with A194 2H heavy hex nuts in blue protective mesh sleeves
    Matched stud and nut kits sleeved to protect threads through transit and site handling

    Overview

    A stud bolt is a threaded rod tensioned between two heavy hex nuts to clamp a gasketed flange, and the grade you choose decides whether that joint survives its design life. EMG supplies stud bolts from 1/4in to 6in diameter and M5 to M150 in any length, in continuous thread, double-end and tap-end configurations, across ASTM A193 B7, B7M and B16, ASTM A320 L7, L7M and L43, ASTM A193 B8, B8M, B8T and B8C, ASTM A453 Grade 660, duplex 2205, super duplex 2507 and nickel alloys including Inconel 625 and 718, Monel 400 and Incoloy 825. Every stud ships as a kit with matching A194 nuts, optional hardened washers, coating applied strictly to the customer specification, and EN 10204 3.1 or 3.2 certification with heat number traceability.

    EMG supplies stud bolts in over 50 material grades — from ASTM A193 B7 to Inconel 718 — with matching A194 nuts, EN 10204 3.1 certification and full heat number traceability as standard on every order.

    Typical Applications

    • Flanged pipe connections in oil & gas facilities
    • Pressure vessel closures and manway covers
    • Heat exchanger tube sheets and shell flanges
    • Valve body-to-bonnet connections
    • Pump and compressor casing assemblies
    • High-temperature steam system flanges

    Fastener Types We Supply

    • Full thread stud bolts (continuous thread)
    • Double-end stud bolts (threaded ends with unthreaded shank)
    • Tap-end studs for blind tapped holes
    • Through-hardened and stress-relieved studs for elevated temperatures
    • Custom length studs to project specifications

    Standards & Documentation

    • EN 10204 3.1 Mill Test Reports with full chemical and mechanical certification
    • Heat number traceability from raw material through finished product
    • PMI (Positive Material Identification) testing available on request
    • Thread gauging to ASME B1.1 / ISO 261 tolerances
    • Manufactured under ISO 9001:2015 certified quality system

    NEED MACHINED COMPONENTS TOO?

    Spacers, blinds, special nuts, shafts and bushes — supplied to your drawing with the same traceability as your bolting. Precision Machined Components →

    RELATED RESOURCES

    ASTM A193 B7 Stud BoltsASTM A193 B7M Sour ServiceMetric Stud Bolts (B7/2H)ASTM A320 L7 Low TemperatureASTM A193 B8 & B8M StainlessASTM A193 B16 High TemperatureASTM A453 660 High TemperatureExotic Alloy Stud BoltsConfigure a Stud Bolt KitPetrochemical Stud Bolts PerthNuts & WashersCoated FastenersASTM Fastener StandardsAPI 20E & 20F BoltingNORSOK M-650 Bolting

    How to choose a stud bolt grade

    Grade selection follows the service condition, not the price list. ASTM A193 B7 is the default for general high-pressure, high-temperature flange bolting to roughly 400 to 500 C. Where wet H2S is present, NACE MR0175 / ISO 15156 requires the hardness-controlled B7M, which trades about 20 percent of the strength for resistance to sulphide stress cracking. Below minus 29 C the material must be Charpy impact tested, which means ASTM A320 L7, L7M or L43. For sustained high temperature above about 450 C, ASTM A193 B16 adds vanadium to resist creep relaxation. Where corrosion rather than load governs, move to stainless B8 or B8M, then to duplex 2205 and super duplex 2507, then to nickel alloys such as Inconel 625, Inconel 718, Monel 400 and Incoloy 825.

    Grade comparison at a glance

    B7 gives 862 MPa minimum tensile and 724 MPa minimum yield up to 2-1/2in and uses A194 2H nuts. B7M gives 689 MPa tensile and 551 MPa yield, is hardness capped at 235 HBW and uses A194 2HM nuts. A320 L7 matches B7 strength and adds impact testing at minus 101 C with A194 Grade 7 nuts. B16 matches B7 at ambient but holds load far better hot, with A194 Grade 4 or 7 nuts. B8 and B8M give 515 MPa tensile in solution annealed Class 1 or up to 860 MPa in strain hardened Class 2, with A194 Grade 8 or 8M nuts. Duplex, super duplex and nickel alloy studs are selected on corrosion resistance and galvanic compatibility with the flange rather than on strength alone.

    Kits, nuts and washers

    A stud bolt is only as good as the nut on it, because A194 nut grades are chosen so the stud yields before the nut thread strips. Mixing grades, reusing nuts of unknown history or fitting metric nuts on imperial studs all defeat that design intent. EMG supplies complete kits — one stud, two matched heavy hex nuts and optional ASTM F436 hardened washers — certified together on a single EN 10204 3.1 document so site inspection is not left reconciling separate paperwork.

    Lengths, threads and coatings

    Standard ASME B16.5 and B16.47 flange stud lengths are held in the common grades and sizes, and non-standard lengths are cut, threaded and re-certified to order. Threads are gauged to ASME B1.1 Class 2A or ISO 261 and 965 as specified, with allowance made where a coating adds thickness. Coating systems including Xylan 1424, GEOMET 321 and 500, PTFE and hot-dip galvanising to AS/NZS 4680 are applied strictly to the customer specification, never substituted, and the applicator certificate forms part of the documentation pack because coating friction directly determines how much of an applied torque becomes bolt load.

    Australian stock and project supply

    EMG holds stud bolt inventory in Australia and supplies project scopes into Queensland, Western Australia, the Northern Territory and across the Asia-Pacific, including Singapore, Malaysia, Indonesia and New Zealand. Project work is supported by consolidated certification packs, bagged and tagged flange-by-flange packaging, and staged delivery against a shutdown schedule. Breakdown and shutdown requirements run through RapidBolt, our 24/7 emergency bolting service.

    FREQUENTLY ASKED QUESTIONS

    Technical FAQs

    What is the difference between a full thread and double-end stud bolt?

    +
    A full thread stud bolt (also called all-thread or continuous thread) has threads running the entire length, allowing nuts to be positioned anywhere. A double-end stud bolt has threads only at each end with an unthreaded shank in the middle, providing a defined grip length. Double-end studs are typically specified for high-pressure flanged connections per ASME B16.5.

    What ASTM grade is most commonly used for stud bolts?

    +
    ASTM A193 Grade B7 is the most widely used stud bolt grade for oil & gas, petrochemical, and refinery applications. It is a chromium-molybdenum alloy steel with a minimum tensile strength of 862 MPa (125 ksi) and is paired with ASTM A194 Grade 2H heavy hex nuts.

    What is the difference between A193 B7 and A320 L7 stud bolts?

    +
    The chemistry and strength are effectively the same. A320 L7 adds mandatory Charpy V-notch impact testing, normally at minus 101 C, which qualifies it for LNG and cryogenic service. B7 carries no impact qualification and is limited to about minus 29 C.

    When do I need B7M instead of B7?

    +
    Whenever wet H2S is present in the service. B7M is tempered to a maximum 235 HBW and hardness tested on every stud to meet NACE MR0175 / ISO 15156, which resists sulphide stress cracking. The trade-off is lower strength, so the joint calculation must be revisited.

    Can you supply stud bolts with matching nuts and washers as a complete set?

    +
    Yes. We supply complete flange bolting sets including stud bolts, heavy hex nuts (ASTM A194), and hardened washers (ASTM F436) matched by heat number and material grade. Sets are supplied with consolidated EN 10204 3.1 certification covering all components.

    What is the maximum size stud bolt you can supply?

    +
    We supply stud bolts up to 6 inches (M150) in diameter in standard alloy steel grades, and custom sizes beyond this range on a project basis. Large diameter studs are available in exotic alloys including Inconel, Duplex, and Super Duplex with full material certification.

    Do you supply NORSOK M-650 compliant stud bolts?

    +
    Yes. We regularly supply stud bolts manufactured to NORSOK M-650 requirements for North Sea and offshore applications. This includes qualification test records (QTR), material data sheets (MDS), and compliance with specific hardness, impact testing, and documentation requirements.

    Can I configure and price a stud bolt kit online?

    +
    Yes. Use our stud bolt kit configurator to select diameter, length, grade and coating, add the kit to a quote request and submit it with your project details. Our team returns pricing, lead time and the applicable certification scope.
    GET IN TOUCH

    Need a Quote for Stud Bolts?

    Send us the size, grade and quantity — or your drawings and bill of materials — and we'll return a technical quote for stud bolts with lead times and certification included.

    Request a Stud Bolts QuoteCall Now

    Emergency Support

    24/7 availability for critical projects