Gulf Union Ozone stocks ASTM A105 forged carbon steel flanges to ASME B16.5 across all five flange types — weld neck, blind, slip-on, socket weld, and threaded — in every pressure class from 150# to 2500#. SAEP-347 compatible. EN 10204 Type 3.1 Mill Test Certificates supplied with every order. Same-day dispatch from Jeddah.
ASTM A105 is the ASTM International standard specification for carbon steel forgings used in piping applications. It covers flanges, valves, fittings, and similar pressure-retaining parts intended for use at ambient and elevated temperatures. ASTM A105 is the most widely specified carbon steel forging grade in oil and gas, petrochemical, refinery, and power piping systems worldwide — and in Saudi Arabian industrial projects in particular.
The specification covers a single composition range — carbon steel with a maximum carbon content of 0.35%, manganese 0.60–1.05%, and silicon 0.10–0.35%. The forgings are produced in the normalised, normalised and tempered, annealed, or quenched and tempered condition. Mechanical property requirements include a minimum tensile strength of 485 MPa (70 ksi) and yield strength of 250 MPa (36 ksi), with Charpy V-notch testing not mandatory for ambient-temperature service.
ASTM A105 forged flanges are manufactured per ASME B16.5 (NPS ½″ to 24″, Class 150 to 2500) or ASME B16.47 (NPS 26″ and larger). Gulf Union Ozone supplies A105 flanges fully conforming to ASME B16.5 dimensional requirements, with EN 10204 Type 3.1 Mill Test Certificates from approved mills traceable to the heat number on each component.
| Element | Max / Range |
|---|---|
| Carbon (C) | 0.35% max |
| Manganese (Mn) | 0.60–1.05% |
| Phosphorus (P) | 0.035% max |
| Sulfur (S) | 0.040% max |
| Silicon (Si) | 0.10–0.35% |
| Copper (Cu) | 0.40% max |
| Nickel (Ni) | 0.40% max |
| Chromium (Cr) | 0.30% max |
| Molybdenum (Mo) | 0.12% max |
| Vanadium (V) | 0.08% max |
ASTM A105 is the standard for forged carbon steel piping components — flanges, fittings, and valves — for ambient and high-temperature service. A105N (normalized) is required by ASME B31.3 and Saudi Aramco SAES-L-108 for all carbon steel flanges above Class 600. The key properties: tensile strength ≥70,000 psi, yield strength ≥36,000 psi, Brinell hardness ≤197 HBW.
All five ASME B16.5 flange types are available in ASTM A105 forged carbon steel from Gulf Union Ozone's Jeddah stock.
| Type | Code | Pressure Classes | Sizes (NPS) | Typical Use |
|---|---|---|---|---|
| Weld Neck | WN | 150# to 2500# | ½″ to 24″ | High-pressure, high-temp, cyclic service |
| Blind | BL | 150# to 2500# | ½″ to 24″ | Line isolation, hydrotesting, blanking |
| Slip-On | SO | 150#, 300# | ½″ to 24″ | Utility, water, low-pressure process |
| Socket Weld | SW | 150# to 2500# | ½″ to 2″ | Small-bore instrument and HP connections |
| Threaded | TH | 150#, 300# | ½″ to 4″ | No-weld applications, low-pressure utility |
Default facing for ASME B16.5 A105 flanges — Class 150 and above. Concentrates gasket load for better sealing. Standard for oil and gas, petrochemical, and Aramco piping systems.
Required when mating with cast iron or ductile iron equipment. Prevents bending of the brittle flanged equipment under bolt-up loads. Class 150 and 300 only.
Grooved face with solid metal ring gasket. Used for Class 900 and above, and mandatory on wellhead / Christmas tree connections. Metal-to-metal seal. Available in A105 on request.
ASTM A105N flanges are available in six face types: raised face (RF) for Class 150–600, ring type joint (RTJ) mandatory for Class 900 and above, flat face (FF) for cast iron equipment, and large male/female and tongue-and-groove for heat exchanger and pressure vessel connections. Weld neck flanges (most common for high-pressure piping), slip-on, socket weld, blind, lap joint, and threaded configurations all use A105N as the body material in carbon steel service.
Saudi Aramco Engineering Procedure SAEP-347 governs the procurement of piping materials for Aramco-operated facilities. Annex 4 of SAEP-347 lists specific approved material numbers for each piping component type. ASTM A105 carbon steel forged flanges appear under several material numbers in Annex 4 — covering standard Class 150 to Class 600 flanges for process piping, utility services, and firewater systems.
For SAEP-347 compliance, each A105 flange supplied by Gulf Union Ozone is accompanied by: (1) EN 10204 Type 3.1 Mill Test Certificate from the originating mill; (2) Gulf Union Ozone Certificate of Conformance referencing the SAEP-347 material number and your purchase order; (3) heat number cross-reference report for Goods Receipt inspection traceability.
Use ASTM A105 for standard process piping above −29°C. Use ASTM A350 LF2 for low-temperature service — gas dehydration, refrigeration loops, LNG — where service temperature may fall below −29°C and Charpy impact at −46°C is required. Gulf Union Ozone stocks both grades.
| Grade | Min Temp | Max Temp | Charpy |
|---|---|---|---|
| A105 | −29°C | 538°C | Not required |
| A350 LF2 | −46°C | 343°C | Required at −46°C |
| A182 F11 | −29°C | 593°C | Not required |
| A182 F316L | −196°C | 816°C | Not required |
Temperature limits per ASME B16.5 Table 2-1.1 for respective material Groups. Consult piping class specification for service-specific limits.
Gulf Union Ozone holds all SAEP-347 Annex 4 flange material numbers that call for ASTM A105N carbon steel — covering Class 150 through 2500 weld neck, slip-on, and blind flanges in sizes ½" to 24" NPS. Every flange order includes an EN 10204 3.1 mill test certificate with chemical composition and mechanical properties, traceable to the original mill heat number. Certificates of Conformance confirming ASME B16.5 compliance are issued with every shipment.
ASTM A105 falls in Group 1.1 under ASME B16.5. Pressure ratings decrease with increasing temperature. The table below shows maximum allowable working pressure (MAWP) in PSI at selected temperatures.
| Class | −29 to 38°C | 100°C | 200°C | 300°C | 400°C | 450°C |
|---|---|---|---|---|---|---|
| Class 150 | 285 | 260 | 230 | 205 | 170 | 140 |
| Class 300 | 740 | 680 | 600 | 535 | 445 | 360 |
| Class 600 | 1480 | 1360 | 1200 | 1070 | 890 | 720 |
| Class 900 | 2220 | 2040 | 1800 | 1600 | 1335 | 1080 |
| Class 1500 | 3705 | 3400 | 3000 | 2670 | 2225 | 1800 |
| Class 2500 | 6170 | 5655 | 5000 | 4440 | 3705 | 3000 |
MAWP values in PSI per ASME B16.5-2017 Table 2-1.1, Group 1.1, for ASTM A105. Ratings are for RF and FF flanges. Always verify against your piping class data sheet. Specifications last verified: September 2026.
To receive an accurate quotation for ASTM A105 carbon steel flanges, provide the following information in your RFQ. Complete specifications allow Gulf Union Ozone to confirm stock availability, issue a quotation, and prepare EN 10204 Type 3.1 documentation within 24 hours.
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| Jeddah (pickup) | Same day |
| Riyadh | 24h |
| Eastern Province | 24–48h |
| All other KSA cities | 48h |
ASTM A105 is the standard specification for carbon steel forgings for piping applications — covering flanges, valves, fittings, and similar pressure-retaining parts. It is used in Classes 150 to 2500 across oil and gas, refinery, petrochemical, and infrastructure piping operating between −29°C and 538°C. A105 is the most commonly specified carbon steel flange grade on Saudi Aramco and EPC projects in Saudi Arabia.
Yes. ASTM A105 forged flanges appear in several material numbers in SAEP-347 Annex 4 for standard carbon steel piping classes. Gulf Union Ozone supplies A105 flanges with EN 10204 Type 3.1 Mill Test Certificates traceable to the heat number on each component — meeting the SAEP-347 documentation requirement for Aramco Goods Receipt inspection.
ASTM A105 can be used in sour service provided hardness does not exceed 22 HRC (237 HBW) — as required by NACE MR0175 / ISO 15156. Standard A105 forgings have a maximum hardness of 187 HBW, which is within the NACE MR0175 limit. For Aramco sour service governed by SAES-L-133, specific hardness testing may also be required — consult your piping class specification.