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ASTM A105 Carbon Steel Flanges Supplier

Forged A105 / A105N pipe flanges to ASME B16.5 and B16.47, from stock in Mumbai, India.

ASTM A105 / ASME SA105 Forged Flanges in Mumbai

ASTM A105 carbon steel forged flanges

Dinesh Tube India supplies ASTM A105 carbon steel flanges from Mumbai to EPC contractors, refineries, power plants, process plants and fabricators in India and abroad. Our flanges are forged and machined to ASTM A105 / ASME SA105 by approved forging manufacturers, and supplied with an EN 10204 3.1 certificate traceable to the heat number.

We supply weld neck, slip-on, blind, socket weld, threaded, lap joint and RTJ flanges from 1/2" to 48", Class 150 to 2500, in A105 or normalised A105N.

This page gives the full technical data for A105. To compare A105 with low-temperature and high-yield flange grades, see our carbon steel flanges page.

Table of Contents


What Is ASTM A105?

ASTM A105 is the standard specification for carbon steel forgings for piping components: flanges, fittings, valve bodies and similar parts for ambient and high-temperature pressure service. ASME adopts it for boiler and pressure vessel work as SA105. It is the most widely used flange material in process piping and is the forged partner of A106 Gr B pipe and A234 WPB fittings.

A105 is a plain carbon–manganese steel. It is not a corrosion-resistant material; flanges are supplied with a rust-preventive oil or paint, and galvanising or coating can be added for outdoor or wet service. For service below −29 °C, use A350 LF2 flanges, which are impact tested at −46 °C.

ASTM A105 Flange Specification

Material

ASTM A105 / ASME SA105; A105N (normalised)

Size

1/2" – 24" (B16.5); 26" – 48" (B16.47 Series A / B)

Pressure Class

Class 150, 300, 600, 900, 1500, 2500; PN 6 – PN 64

Dimensions

ASME B16.5, B16.47, B16.48 (line blanks), EN 1092-1, BS 4504, DIN

Types

WN, SO, blind, SW, threaded, lap joint, long weld neck, spectacle blind, orifice

Face

Raised face (RF), flat face (FF), ring type joint (RTJ)

Bore / Schedule

SCH 10 to XXS to match pipe (weld neck and socket weld)

Facing Finish

Serrated 125–250 µin Ra (3.2–6.3 µm) or as specified

Coating

Rust-preventive oil, black paint, yellow primer, hot-dip galvanised

Certification

EN 10204 3.1; 3.2 / third-party inspection; NACE MR0175 on request
ASTM A105 flange specification

ASTM A105 Chemical Composition

ElementLimit, %
Carbon (C)0.35 max
Manganese (Mn)0.60 – 1.05
Phosphorus (P)0.035 max
Sulphur (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
Cu + Ni + Cr + Mo + V1.00 max
Cr + Mo0.32 max
Carbon equivalent (CE)0.47 max (≤ 2" thick), 0.48 max (> 2")

For each 0.01% carbon below 0.35%, manganese may be increased by 0.06% above 1.05%, up to 1.35% max. CE = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15.

ASTM A105 Mechanical Properties

PropertyRequirement
Tensile strength, min485 MPa (70 ksi)
Yield strength, min250 MPa (36 ksi)
Elongation in 2 in. (50 mm), min30% (basic), 22% (4D round specimen)
Reduction of area, min30%
Hardness137 – 187 HBW

A105 vs A105N Flanges

A105A105N
StandardASTM A105ASTM A105, ordered normalised
Heat treatmentAs-forged allowed for many parts; annealing, normalising, normalising and tempering, or quench and tempering where requiredNormalised (sometimes normalised and tempered)
Grain structureCan be coarse in as-forged partsFine, uniform grain
ToughnessNot specifiedBetter and more consistent; Charpy test only if ordered
Typical useGeneral and utility pipingRefinery, oil and gas and project specs that call for normalising

"A105N" is not a separate grade in ASTM A105; the N means the flange is normalised, which many project specifications require. Under A105, heat treatment is mandatory for flanges above Class 300 and for some other parts. Normalising does not make A105N suitable for low-temperature service; for that, use A350 LF2.

A105 Flange Pressure–Temperature Ratings (ASME B16.5)

TemperatureClass 150Class 300Class 600Class 900Class 1500
−29 to 38 °C19.6 bar51.1 bar102.1 bar153.2 bar255.3 bar
100 °C17.7 bar46.6 bar93.2 bar139.8 bar233.0 bar
200 °C13.8 bar43.8 bar87.6 bar131.4 bar219.0 bar
300 °C10.2 bar39.8 bar79.6 bar119.5 bar199.1 bar
400 °C6.5 bar34.7 bar69.4 bar104.2 bar173.6 bar

Material Group 1.1. Class 2500 at 38 °C is 425.5 bar. Prolonged service above about 425 °C can cause graphitisation of carbon steel; check ASME B16.5 and your design code for the exact rating at design temperature.

Need ASTM A105 flanges? Send your flange type, size, class, face, bore schedule and quantity to kamlesh@dineshtube-india.com or call +91 83559 10913. You can also send an enquiry.

Types of ASTM A105 Flanges

ASTM A105 weld neck flange WNRF

A105 Weld Neck Flange

Butt-welded tapered hub for high pressure, temperature and cyclic service.
ASTM A105 slip-on flange SORF

A105 Slip-On Flange

Slides over the pipe and is fillet welded; low-cost choice for lower pressure.
ASTM A105 blind flange BLRF

A105 Blind Flange

Closes the end of a line, valve or nozzle; allows later extension.
ASTM A105 socket weld flange SWRF

A105 Socket Weld Flange

For small-bore lines, usually 2" and below, with a fillet weld.
ASTM A105 threaded flange NPT

A105 Threaded Flange

NPT threaded, no welding; for small, low-pressure and non-hazardous lines.
ASTM A105 ring type joint RTJ flange

A105 RTJ Flange

Ring groove for a metal ring gasket; high-pressure Class 600 and above.

Inspection and Testing

  •   Heat and product chemical analysis, with carbon equivalent reported
  •   Tensile and hardness tests per heat and heat-treatment lot
  •   Dimensional and visual inspection to ASME B16.5 / B16.47
  •   PMI, ultrasonic or magnetic particle testing on request
  •   Charpy impact test (supplementary) when ordered
  •   Marking with grade, size, class, heat number and standard

Flanges are packed with face protectors in wooden cases or on pallets for export.

ASTM A105 Flange Applications

  •   Refinery and petrochemical process piping
  •   Oil and gas plants and pipelines
  •   Steam, condensate and boiler feedwater lines
  •   Power plants and utilities
  •   Water, fire-fighting and cooling water systems
  •   Valve, pump and pressure vessel nozzle connections
Industries using ASTM A105 flanges

A105 flanges are normally used with A106 Gr B, A53 Gr B and API 5L Gr B pipe and carbon steel pipe fittings.

ASTM A105 Flanges: FAQs

What is ASTM A105 flange material?

ASTM A105 is forged carbon steel for piping components such as flanges, fittings and valve bodies, used at ambient and elevated temperatures. It has a minimum tensile strength of 485 MPa (70 ksi), minimum yield of 250 MPa (36 ksi) and a maximum hardness of 187 HBW. ASME adopts it as SA105.

What is the difference between A105 and A105N flanges?

A105N is A105 that has been normalised. ASTM A105 allows many flanges to be supplied as-forged, while A105N is always heat treated by normalising, which refines the grain and gives more consistent strength and toughness. Many refinery and oil and gas specifications call for A105N.

Is ASTM A105 the same as ASME SA105?

Yes, for practical purposes. ASME Section II adopts ASTM A105 as SA105 for use in boilers and pressure vessels, sometimes with minor additions. Flanges are often dual marked A105 / SA105.

What is the maximum temperature for A105 flanges?

ASME B16.5 gives ratings for A105 (Material Group 1.1) up to 538 °C, but prolonged service above about 425 °C can cause graphitisation of the carbide phase in carbon steel, so alloy steel flanges such as A182 F11 or F22 are usually chosen for sustained high-temperature service. The minimum is −29 °C; below that, use A350 LF2.

Can A105 flanges be used for low-temperature service?

Not below −29 °C as standard, because A105 is not impact tested. For low-temperature service use ASTM A350 LF2 Class 1 flanges, which are Charpy tested at −46 °C, with A333 Gr 6 pipe and A420 WPL6 fittings.

Are you a manufacturer of A105 flanges?

We are a supplier and exporter. Our A105 flanges are forged and machined by approved forging manufacturers to ASTM A105 and ASME B16.5, and we supply them with mill test certificates, third-party inspection when required, and export packing, along with matching pipe and fittings.

Export Destinations for A105 Flanges

We export ASTM A105 flanges to the Middle East (UAE, Saudi Arabia, Qatar, Kuwait, Oman, Bahrain, Iraq), Africa (Nigeria, Egypt, South Africa, Kenya, Ghana, Tanzania), Asia (Bangladesh, Sri Lanka, Nepal, Indonesia, Malaysia, Thailand, Vietnam, Philippines), Europe and the Americas on request.