ADNOC & Aramco AVL Approved Manufacturer

API 20E & 20F Certified Oil & Gas Bolting & Studbolts

Highest integrity critical bolting, studbolt assemblies, heavy hex nuts, and precision fasteners manufactured under strict API 20E (BSL 1, 2, 3) and API 20F (BSL 2, 3) standards for subsea, drilling, and refinery environments.

API Spec 20E 3rd Edition Compliant
ADNOC Approved AVL Vendor & Saudi Aramco Approved AVL

The oil and gas industry operates under some of the most aggressive pressure, thermal, and corrosive conditions on earth. From ultra-deepwater subsea drilling risers to high-pressure/high-temperature (HP/HT) surface trees and refineries, mechanical integrity depends entirely on critical bolting. As an ADNOC Approved AVL Vendor and Saudi Aramco Approved AVL manufacturer, Intact360 guarantees zero-defect fastener reliability for major national oil companies (NOCs) and international EPC contractors worldwide.

Intact360 Industries manufactures and supplies a complete spectrum of certified API 20E (alloy & carbon steel) and API 20F (corrosion-resistant alloy) bolting products. Incorporating the stringent requirements of the API Spec 20E Third Edition, our manufacturing processes guarantee complete raw material traceability, controlled heat treatment, rigorous non-destructive examination (NDE), and precise dimensional verification.

Key Highlights of Intact360 API 20E & 20F Bolting Capabilities
  • Approved Vendor Approvals: ADNOC Approved AVL Vendor and Saudi Aramco Approved AVL Manufacturer.
  • Fully certified manufacturing to API 20E BSL-1, BSL-2, BSL-3 and API 20F BSL-2, BSL-3 requirements.
  • Full compliance with API Spec 20E Third Edition processes and procedures.
  • Extensive raw material stock including ASTM A193, A320, A194, A453, A540, Duplex, and CRA Nickel Alloys.
  • Supplied with comprehensive EN 10204 3.1 / 3.2 Material Test Certificates covering heat analysis, Charpy impact, hardness, and NDT reports.
  • Precision manufactured products: Fully Threaded Studbolts, ASTM A194 2H/7 Heavy Hex Nuts, Tap End Studs, Collar Flange Bolts, Hex Bolts, Socket Head Cap Screws, 12-Point Fasteners, and Engineered Heavy Washers.
  • Specialized anti-corrosion coatings including Xylan/PTFE, Zinc-Nickel, Cadmium, Hot-Dip Galvanizing, Phosphating, and Copper Plating.
  • Fast-track production lines for urgent shutdown and project turnaround deliveries worldwide.
API 20E and API 20F Studbolts from Intact360
API 20E / 20F Fully Threaded Studbolts & Heavy Hex Nuts
Heavy Hex Nuts and Tap End Studs for Oil and Gas Intact360
Subsea Tap End Studs & ASTM A194 2H/7 Heavy Hex Nuts

Oil & Gas Fastener Product Portfolio

Intact360 manufactures a full range of high-pressure, severe-service fastener geometries engineered to ASME, ANSI, DIN, ISO, and client-specific drawings for onshore, offshore, and subsea oilfield installations:

Fully Threaded Studbolts

Continuous threaded studs engineered for high-pressure ANSI/API flanged joints and pressure vessel connections.

ASTM A194 2H Heavy Hex Nuts

High-strength heat-treated heavy hex nuts (2H, 2HM, 7, 7M, 8M, 16) designed to match high tensile studbolts under severe tension.

Tap End Studs

Double-ended studs with a shorter thread length on one end engineered for threading directly into tapped valve bodies and pump casings.

Flange (Collar Bolts)

Precision collar bolts engineered for subsea pipeline flanges, Compact Flanges, and specialized API wellhead equipment.

Hexagon Bolts & Screws

Heavy hex structural bolts and machine screws manufactured to close tolerances for structural steel and equipment mounting.

Socket Head Capscrews

High tensile internal drive fasteners ideal for confined spaces in blowout preventers (BOPs), chokes, and control manifolds.

12-Point Bolts & Nuts

High-fatigue, high-strength 12-point flange fasteners widely specified in subsea trees, turbines, and aerospace-grade oilfield machinery.

Hardened Heavy Washers

Heavy-duty structural washers (ASTM F436 / DIN 6916) providing uniform load distribution across critical circular flange faces.

Bi-Hexagon & Specialized Fasteners

Custom engineered 12-point bi-hex bolts, slotted nuts, collar studs, and bespoke machining fasteners engineered to OEM drawings.

API 20E & 20F Bolting Specification Levels (BSL)

The American Petroleum Institute establishes three distinct Bolting Specification Levels (BSL-1, BSL-2, and BSL-3). These BSL designations define ascending technical, quality, testing, and qualification criteria. As the consequence of potential bolting failure increases in critical applications, higher BSL levels are specified to eliminate risk.

  • BSL-1 (API 20E Only): Establishes baseline quality, chemical composition, heat treatment, and mechanical testing requirements for standard alloy and carbon steel oilfield bolting.
  • BSL-2 (API 20E & API 20F): Introduces enhanced volumetric non-destructive examination (NDE), stricter heat treatment controls, elevated temperature testing, and magnetic particle / liquid penetrant inspection.
  • BSL-3 (API 20E & API 20F): Represents the absolute pinnacle of quality criticality. Reserved for applications where bolting failure is not an acceptable option, requiring 100% NDE inspection, microstructural analysis, and individual component serial traceability.
API Critical Oil and Gas Bolting Manufacturing Intact360

Comprehensive Material Grades & Alloys Stocked

Intact360 maintains extensive mill-certified raw bar stock, enabling rapid production across standard carbon steels, high-temperature alloys, stainless steels, duplex alloys, heat resisting grades, and exotic non-ferrous metals:

Carbon & Alloy Steels API 20E Qualified
ASTM A193 B7 ASTM A193 B7M ASTM A320 L7 ASTM A320 L7M ASTM A320 L43 Property Class 8.8 Property Class 10.9 Property Class 12.9 ASTM A540 B23 (Class 1 - 5) ASTM A540 B24 (Class 1 - 5) ASTM A194 2H / 2HM ASTM A194 Grade 7 / 7M
Stainless Steels CRA Alloys
ASTM A193 B8 (Class 1 & 2) ASTM A193 B8M (Class 1 & 2) ASTM A193 B8T (Class 1 & 2) ASTM A193 B8C ASTM A193 B6 ASTM A453 660 (Grades A, B, C, D) 17/4 PH (UNS S17400) A2 / A4 (Class 50, 70, 80) UNS S31254 / 254SMO® Nitronic 50® Nitronic 60® Urea Grade 25.22.2® SS 310 SS 321 SS 410
Nickel Alloys API 20F & API 6ACRA
Inconel® 625 Inconel® 718 (API 6ACRA) Inconel® 800 (HT) Inconel® 825 Inconel® 925 Hastelloy® C-276 Hastelloy® C-22 Hastelloy® X Monel® 400 Monel® K500 UNS N07716 (120K/140K) UNS N07725 (120K/140K) UNS N09945 (125K/140K)
Duplex & Super Duplex Steels Subsea Service
UNS S32760 (Zeron 100) UNS S32750 (2507) UNS S31803 UNS S32205 (2205) UNS S32550 (Ferralium 255)
Heat Resisting Alloys High Temperature
ASTM A193 Grade B16 Durehete 1055™ Nimonic 80A™ Nimonic 90™
Non-Ferrous & Titanium Alloys Marine & Defence
Hiduron® Cupro Nickel (CuNi 90/10 & 70/30) Aluminum Bronze (C63000 / C63200) Phosphor Bronze Titanium Grade 2 Titanium Grade 5 (Ti-6Al-4V) Titanium Grade 7 NES 833 / 834 / 835 Def Stan Materials

Mandatory Applications Across API Specifications

API 20E and API 20F compliant bolting is mandatory for critical equipment manufactured in accordance with key energy standards, including API 6A, API 6D, API 6DSS, API 16A, API 16C, and API 17D.

Primary oil & gas equipment utilizing our certified bolting includes:

  • Blow Out Preventers (BOPs) & Drill-Through Equipment
  • Subsea Wellheads, Christmas Trees & Manifolds
  • Drilling & Production Risers, Jumpers & Gas Export Systems
  • High Pressure / High Temperature (HP/HT) Flanged Connections
  • Pipeline Valves, Choke & Kill Manifolds, and Subsea Connectors

API 20E Alloy Steel Material Specifications

Standard Material Grade Specification Type Service & Operating Conditions
ASTM A193 Grade B7 / B7M Alloy Steel (AISI 4140/4142) High-temperature and standard high-pressure oilfield service. B7M variant features 100% hardness testing for NACE MR0175 sour service.
ASTM A320 Grade L7 / L7M / L43 Low-Temperature Alloy Steel Severe low-temperature impact service (down to -150°F / -101°C). L43 offers enhanced hardenability for heavy section studs.
ASTM A194 Grade 2H / 7 / 2HM / 7M High Tensile Heavy Hex Nuts Companion heavy hex nuts engineered to match A193 and A320 studbolts under extreme tensile loads and sour service environments.
ASTM A540 Grade B22 / B23 (Class 1-5) Special High-Strength Alloy Steel Extreme strength bolting for nuclear, subsea BOP, and ultra-high pressure wellhead containment systems.

API 20F Corrosion Resistant Material Specifications

CRA Alloy Grade Material Class / Strength Level Corrosion Resistance & Applications
ASTM A453 Grade 660 Class A, B, C & D (A286 Stainless) High-temperature precipitation hardening iron-base CRA alloy for subsea and valve flange bolting.
API 6ACRA UNS N07716 / N07725 Inconel® 716 / 725 (120K & 140K) Age-hardened nickel alloys with outstanding resistance to hydrogen embrittlement, pitting, and sour gas corrosion.
API 6ACRA UNS N07718 Inconel® 718 (120K & 140K) High-strength nickel-chromium CRA alloy engineered for extreme HP/HT subsea wellhead and BOP bolting.
API 6ACRA UNS N09925 / N09935 / N09945 Incoloy® 925 / 945 (110K, 125K, 140K) Premium nickel-iron-chromium alloys offering immunity to chloride stress corrosion cracking in aggressive oilfield brine.
UNS R30035 (MP35N®) Work Strengthened & Aged Ultra-high strength cobalt-nickel-chromium-molybdenum alloy for supreme subsea critical service applications.
Duplex & Super Duplex UNS S31803, S32205, S32750, S32760 High PREN stainless steels for marine, offshore riser, and subsea manifold piping systems.

Advanced Protective Coatings & Surface Finishes

To prevent galling, ensure uniform torque-tension relationships, and withstand marine atmospheric exposure, Intact360 applies high-performance surface coatings engineered specifically for energy infrastructure.

Our comprehensive coating options include:

  • PTFE Fluoropolymer (Xylan® / Xylar®): Multi-layer low friction coatings providing exceptional chemical barrier protection and consistent torque coefficients.
  • Zinc-Nickel Electroplating (ZnNi): High-performance sacrificial alloy coating enduring 1,500+ hours of continuous salt spray testing without red rust formation.
  • Hot-Dip Galvanizing (HDG) & Sherardizing: Heavy duty zinc coatings ideal for structural marine and offshore topside installations.
  • Cadmium & Copper Plating: Excellent anti-galling lubrication properties for high-pressure threaded valve stem and subsea connections.
  • Zinc & Manganese Phosphating: Oil-retaining baseline protective finishes for standard indoor and oil-immersed subsea machinery.
Short Lead Time & Emergency Shutdown Deliveries

We understand that unplanned drilling rig downtime and refinery turnarounds cost millions. Intact360 maintains substantial raw material stock of API-compliant alloys, allowing rapid execution and short-lead manufacturing of custom studbolts, tap end studs, and heavy hex nuts for urgent global dispatch.

Bulk API Bolting Procurement

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Technical FAQ

API 20E & API 20F Bolting Technical FAQ

What is the difference between API 20E and API 20F bolting specifications?
API 20E governs carbon steel and alloy steel bolting used in petroleum and natural gas equipment, whereas API 20F specifies requirements for corrosion-resistant bolting such as stainless steels, CRA nickel alloys, and age-hardened alloys.
What are Bolting Specification Levels (BSL-1, BSL-2, and BSL-3)?
BSLs define ascending levels of technical, quality, qualification, and testing severity. BSL-1 covers standard severe applications, BSL-2 increases quality controls, and BSL-3 represents the highest criticality level reserved for applications where bolting failure is not an acceptable option.
What API equipment specifications mandate API 20E and API 20F fasteners?
API 20E/20F bolting is mandatory across API 6A (Wellhead & Christmas Tree), API 6D (Pipeline Valves), API 6DSS (Subsea Valves), API 16A (Drill-Through Equipment), API 16C (Choke & Kill Systems), and API 17D (Subsea Wellheads & Trees).
What material grades are qualified under API 20E and API 20F?
API 20E includes ASTM A193 B7/B7M, A320 L7/L7M/L43, A194 2H/7/2HM/7M, and A540 B22/B23. API 20F covers ASTM A453 Grade 660 Class D, API 6ACRA N07716, N07718, N07725, N09925, N09935, N09945, and UNS R30035.
What anti-corrosion protective coatings are available for subsea studbolts?
Protective coatings include PTFE fluoropolymer (Xylan/Xylar), Zinc-Nickel, Hot-Dip Galvanizing, Cadmium plating, Sherardizing, Zinc/Manganese Phosphating, Copper Plating, and Zinc Flake coatings.
Does Intact360 supply material test certificates with API 20E and 20F orders?
Yes. All Intact360 API 20E and 20F bolting products are delivered with complete EN 10204 3.1 or 3.2 material test certificates covering raw material heat traceability, heat treatment charts, NDT results, Charpy impact testing, microstructural evaluation, and dimensional verification.
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