ANSI B16.5 Flanges, ASME B16.5 Flange Material Supplier, Manufacturer, Exporter in India
Amardeep Steel, based in Mumbai, manufactures and exports ASME B16.5 Flanges which happens to be the flange standard you'll find in piping systems across the world. We produce these flanges from NPS 1/2" through NPS 24" (larger sizes up to 48" available on request), in pressure classes ranging from 150 to 2500. Materials? We work with carbon steel, stainless steel, alloy steel, duplex and nickel alloy grades.
We've been at this for over thirty years now, shipping to more than 65 countries. Our ASME B16.5 flanges come ISO-certified and include weld neck, slip-on, blind, socket weld, threaded, lap joint, reducing types. Every piece is manufactured to ASTM material specs and tested according to EN 10204/3.1B standards. You'll get full Mill Test Reports with your order, plus third-party inspection reports when needed.
This page covers everything you need: dimensions, pressure-temperature ratings, weight charts, tolerances, and material grades for ASME B16.5 flanges. Need a quote? Our team typically responds the same day.
Table of Contents
What Is ASME B16.5?
ASME B16.5 (Steel Pipe Flanges and Flanged Fittings) is the most widely used flange standard in the global piping industry. Originating from ASA B16E (1932) and formally redesignated ASME B16.5 in 1996, the standard governs flanges and flanged fittings in sizes NPS 1/2" (DN 15) to NPS 24" (DN 600) across seven pressure classes: Class 150, 300, 400, 600, 900, 1500, and 2500. The standard specifies pressure-temperature ratings, dimensions, tolerances, material requirements, identification markings, and testing methods for cast and forged steel pipe flanges. For sizes NPS 26" and above, the corresponding standard is ASME B16.47.
ASME B16.5 Flange Identification Markings
All ASME B16.5 flanges must be marked per MSS SP-25 with the following:
- Manufacturer name or trademark
- Material designation, e.g. ASTM A105
- Pressure class, e.g. CL150
- Standard conformance, B16.5
- Size (NPS)
- Temperature rating where applicable
- For Ring Type Joint flanges: letter R and groove number
Amardeep Steel flanges are fully marked and shipped with EN 10204 / 3.1B Mill Test Reports.
ASME B16.5 Flange Specifications - Standards, Sizes & Pressure Classes
| Specification | Detail |
|---|---|
| Standards | ASME/ANSI B16.5, B16.47 Series A & B, B16.48, BS4504, BS 10, EN-1092, DIN, GOST, ASME/ANSI B16.36/16.47A/16.47B, MSS SP44, ISO 70051, JIS B2220, BS1560-3.1, API 605, EN 1092 |
| Size Range | NPS 1/2" (DN 15) to NPS 24" (DN 600) per ASME B16.5 | Up to NPS 48" (DN 1200) per ASME B16.47 |
| Pressure Classes | Class 150, 300, 400, 600, 900, 1500, 2500 |
| DIN Pressure Ratings | PN6, PN10, PN16, PN25, PN40, PN64 |
| JIS Ratings | 5K, 10K, 16K, 20K, 30K, 40K, 63K |
| Flange Face Types | Raised Face (RF), Ring Type Joint (RTJ), Flat Face (FF), Large Male-Female (LMF), Lap-Joint Face (LJF), Small Male-Female (SMF), Small/Large Tongue & Groove |
| Production Technique | Forged, heat treated and machined |
| Coating Options | Oil black paint, anti-rust paint, zinc plated, yellow transparent, cold and hot dip galvanized |
| Test Certificates | EN 10204/3.1B, 100% Radiography Test Report, Third Party Inspection Report, Raw Materials Certificate |
| Non-Destructive Testing | Direct-reading spectrograph, hydrostatic testing machine, X-ray detector, ultrasonic flaw detector, magnetic particle detector |
| NACE Compliance | MTC per EN 10204 3.1 and EN 10204 3.2, NACE MR0103, NACE MR0175 |
| Special Design | As per customer drawing |
| Uses & Applications | Oil & gas pipelines, petrochemical & acid processing, chemical plants, power generation, water treatment, food & beverage, paper & pulp, offshore platforms, nuclear power, shipbuilding |
| Export Countries | Saudi Arabia, UAE, USA, UK, Germany, Singapore, Australia, South Africa, Canada, and 60+ other countries |
Types of ASME B16.5 Flanges
ASME B16.5 covers the following flange types, each suited to specific pressure, temperature, and installation requirements:
Weld Neck Flange (WNRF)
Long tapered hub welded to the pipe. Best suited for high-pressure and high-temperature systems where structural integrity and leak prevention are critical.
Slip-On Flange (SORF)
Slides over the pipe and is fillet welded inside and out. Lower cost and easier to align than weld neck; suitable for low to moderate pressure.
Blind Flange (BLRF)
Closes the end of a pipe, valve, or pressure vessel opening. Used for isolation, pressure testing, and future expansion points.
Socket Weld Flange (SWRF)
Pipe inserts into a socket bore and is fillet welded. Used for small bore, high-pressure lines where fatigue resistance is important.
Threaded / Screwed Flange
Screws directly onto externally threaded pipe. No welding required; ideal for systems where welding is impractical or hazardous.
Lap Joint Flange
Used in conjunction with a stub end. The flange slides freely over the pipe, allowing easy alignment of bolt holes and frequent dismantling.
Reducing Flange
Connects pipes of two different nominal diameters in a single fitting, eliminating the need for a separate reducer.
Long Weld Neck Flange (LWN)
Extended hub used as a nozzle connection on vessels, columns, and heat exchangers. Common in refinery and petrochemical applications.
ASME B16.5 Flange Material Grades - Carbon Steel, Stainless Steel & Alloy
ASME B16.5 Flanges are manufactured from the following ASTM/ASME-approved material grades. Select the grade that matches your service conditions, corrosion requirements, and pressure class:
| Material Category | Grades / Specifications |
|---|---|
| Stainless Steel Flanges | ASTM/ASME A/SA182 F304, F304L, F316, F316L; ASTM/ASME A/SA351 CF8, CF3, CF8M, CF3M; DIN 1.4301, 1.4306, 1.4401, 1.4404, 1.4308, 1.4408, 1.4409 |
| Carbon Steel Flanges | ASTM/ASME A/SA105, A/SA105N, A/SA216-WCB; DIN 1.0402, 1.0460, 1.0619; ASTM A350 LF2; High Yield ASTM A694 (F52 F56 F60 F65 F70 F80) |
| Alloy Steel Flanges | ASTM A182 / ASME SA182 F5, F9, F11, F12, F22, F91 |
| Duplex Steel Flanges | S31803 / S32205 — A182 Gr F51 / F52 / F53 / F55 / F60 / F61 |
| Super Duplex Stainless Steel Flanges | S32750 / S32760 — A182 Gr F51 / F52 / F53 / F55 / F60 / F61 |
| Titanium Flanges | ASTM B381 / ASME SB381 — Gr. 1, Gr. 2, Gr. 4, Gr. 5, Gr. 7 |
| Copper Nickel Flanges | ASTM/ASME SB 61/62/151/152; Cu-Ni 90/10 (C70600); Cu-Ni 70/30 (C71500); UNS C71640 |
| Inconel Flanges | ASTM B564 / ASME SB564 — Inconel 600, 601, 625, 718, 690, X750 |
| Monel Flanges | ASTM B564 / ASME SB564 — Monel 400 (N04400), Monel 500 (N05500) |
| Hastelloy Flanges | ASTM B564 / ASME SB564 — Hastelloy C276, C22, C4, C2000, B2, B3, X |
| Nickel Alloy Flanges | ASTM B564 / ASME SB564 — Nickel 200, 201, 205, 205LC |
| Incoloy Flanges | ASTM B564 / ASME SB564 — Incoloy 800, 800H, 800HT, 825, 925 |
| Alloy 20 | ASTM B462 / ASME SB462 — Alloy 20Cb-3 |
| 254 SMO | ASTM A182 / ASME SA182, UNS S31254, DIN 1.4547 |
| Aluminium | 5052 / 6061 / 6063 / 2017 / 7075 |
| Nimonic | Nimonic 75, 80A, 90 |
| Other | Tin bronze, Aluminium bronze, Lead bronze; Brass 3602/2604/H59/H62; Copper T1/T2/C10100–C17200 series |
ASME B16.5 Flange Dimensions - Class 150 to 2500 (All Sizes)
All dimensions are in inches. These tables cover weld neck (WN), slip-on (SO), and blind flange configurations for each pressure class as defined in ASME B16.5 Table E1.1 through E7.1.
ASME B16.5 Class 150 Flange Dimensions
Class 150 flanges are the most widely used pressure class, suitable for general service applications at lower pressures and temperatures. Sizes NPS 1/2" to NPS 24".
| NPS | OD | Min.T | RF Dia. | Bolt Holes | Hole Dia. | Bolt Circle | SO Bore | WN Bore | Hub Base | Hub Top | SO LTH | WN LTH |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/2 | 3.50 | 0.38 | 1.38 | 4 | 0.62 | 2.38 | 0.88 | 0.62 | 1.19 | 0.84 | 0.56 | 1.81 |
| 3/4 | 3.88 | 0.44 | 1.69 | 4 | 0.62 | 2.75 | 1.09 | 0.82 | 1.50 | 1.05 | 0.56 | 2.00 |
| 1 | 4.25 | 0.50 | 2.00 | 4 | 0.62 | 3.12 | 1.36 | 1.05 | 1.94 | 1.32 | 0.62 | 2.12 |
| 1-1/4 | 4.62 | 0.56 | 2.50 | 4 | 0.62 | 3.50 | 1.70 | 1.38 | 2.31 | 1.66 | 0.75 | 2.19 |
| 1-1/2 | 5.00 | 0.62 | 2.88 | 4 | 0.62 | 3.88 | 1.95 | 1.61 | 2.56 | 1.90 | 0.81 | 2.38 |
| 2 | 6.00 | 0.69 | 3.62 | 4 | 0.75 | 4.75 | 2.44 | 2.07 | 3.06 | 2.38 | 0.94 | 2.44 |
| 2-1/2 | 7.00 | 0.81 | 4.12 | 4 | 0.75 | 5.50 | 2.94 | 2.47 | 3.56 | 2.88 | 1.06 | 2.69 |
| 3 | 7.50 | 0.88 | 5.00 | 4 | 0.75 | 6.00 | 3.57 | 3.07 | 4.25 | 3.50 | 1.12 | 2.69 |
| 3-1/2 | 8.50 | 0.88 | 5.50 | 8 | 0.75 | 7.00 | 4.07 | 3.55 | 4.81 | 4.00 | 1.19 | 2.75 |
| 4 | 9.00 | 0.88 | 6.19 | 8 | 0.75 | 7.50 | 4.57 | 4.03 | 5.31 | 4.50 | 1.25 | 2.94 |
| 5 | 10.00 | 0.88 | 7.31 | 8 | 0.88 | 8.50 | 5.66 | 5.05 | 6.44 | 5.56 | 1.38 | 3.44 |
| 6 | 11.00 | 0.94 | 8.50 | 8 | 0.88 | 9.50 | 6.72 | 6.07 | 7.56 | 6.63 | 1.50 | 3.44 |
| 8 | 13.50 | 1.06 | 10.62 | 8 | 0.88 | 11.75 | 8.72 | 7.98 | 9.69 | 8.63 | 1.69 | 3.94 |
| 10 | 16.00 | 1.12 | 12.75 | 12 | 1.00 | 14.25 | 10.88 | 10.02 | 12.00 | 10.75 | 1.88 | 3.94 |
| 12 | 19.00 | 1.19 | 15.00 | 12 | 1.00 | 17.00 | 12.88 | 12.00 | 14.38 | 12.75 | 2.12 | 4.44 |
| 14 | 21.00 | 1.31 | 16.25 | 12 | 1.12 | 18.75 | 14.14 | 13.25 | 15.75 | 14.00 | 2.19 | 4.94 |
| 16 | 23.50 | 1.38 | 18.50 | 16 | 1.12 | 21.25 | 16.16 | 15.25 | 18.00 | 16.00 | 2.44 | 4.94 |
| 18 | 25.00 | 1.50 | 21.00 | 16 | 1.25 | 22.75 | 18.18 | 17.25 | 19.88 | 18.00 | 2.62 | 5.44 |
| 20 | 27.50 | 1.62 | 23.00 | 20 | 1.25 | 25.00 | 20.20 | 19.25 | 22.00 | 20.00 | 2.81 | 5.62 |
| 22 | 29.50 | 1.75 | 25.25 | 20 | 1.38 | 27.25 | 22.22 | 21.25 | 24.25 | 22.00 | 3.07 | 5.82 |
| 24 | 32.00 | 1.81 | 27.25 | 20 | 1.38 | 29.50 | 24.25 | 23.25 | 26.12 | 24.00 | 3.19 | 5.94 |
ASME B16.5 Class 300 Flange Dimensions
Class 300 flanges carry significantly higher working pressures than Class 150 at the same temperature. Used in medium-to-high pressure piping systems. All dimensions in inches.
| NPS | OD | Min.T | RF Dia. | Bolt Holes | Hole Dia. | Bolt Circle | SO Bore | WN Bore | Hub Base | Hub Top | SO LTH | WN LTH |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/2 | 3.75 | 0.50 | 1.38 | 4 | 0.63 | 2.62 | 0.88 | 0.62 | 1.50 | 0.84 | 0.81 | 2.00 |
| 3/4 | 4.62 | 0.56 | 1.69 | 4 | 0.75 | 3.25 | 1.09 | 0.82 | 1.88 | 1.05 | 0.94 | 2.19 |
| 1 | 4.88 | 0.62 | 2.00 | 4 | 0.75 | 3.50 | 1.36 | 1.05 | 2.12 | 1.32 | 1.00 | 2.38 |
| 1-1/4 | 5.25 | 0.69 | 2.50 | 4 | 0.75 | 3.88 | 1.70 | 1.38 | 2.50 | 1.66 | 1.00 | 2.50 |
| 1-1/2 | 6.12 | 0.75 | 2.88 | 4 | 0.88 | 4.50 | 1.95 | 1.61 | 2.75 | 1.90 | 1.13 | 2.63 |
| 2 | 6.50 | 0.81 | 3.62 | 8 | 0.75 | 5.00 | 2.44 | 2.07 | 3.31 | 2.38 | 1.25 | 2.69 |
| 2-1/2 | 7.50 | 0.94 | 4.12 | 8 | 0.88 | 5.88 | 2.94 | 2.47 | 3.94 | 2.88 | 1.44 | 2.94 |
| 3 | 8.25 | 1.06 | 5.00 | 8 | 0.88 | 6.62 | 3.57 | 3.07 | 4.62 | 3.50 | 1.63 | 3.06 |
| 3-1/2 | 9.00 | 1.12 | 5.50 | 8 | 0.88 | 7.25 | 4.07 | 3.55 | 5.25 | 4.00 | 1.69 | 3.13 |
| 4 | 10.00 | 1.19 | 6.19 | 8 | 0.88 | 7.88 | 4.57 | 4.03 | 5.75 | 4.50 | 1.82 | 3.32 |
| 5 | 11.00 | 1.31 | 7.31 | 8 | 0.88 | 9.25 | 5.66 | 5.05 | 7.00 | 5.56 | 1.94 | 3.82 |
| 6 | 12.50 | 1.38 | 8.50 | 12 | 0.88 | 10.62 | 6.72 | 6.07 | 8.12 | 6.63 | 2.00 | 3.82 |
| 8 | 15.00 | 1.56 | 10.62 | 12 | 1.00 | 13.00 | 8.72 | 7.98 | 10.25 | 8.63 | 2.38 | 4.32 |
| 10 | 17.50 | 1.81 | 12.75 | 16 | 1.12 | 15.25 | 10.88 | 10.02 | 12.62 | 10.75 | 2.56 | 4.56 |
| 12 | 20.50 | 1.94 | 15.00 | 16 | 1.25 | 17.75 | 12.88 | 12.00 | 14.75 | 12.75 | 2.82 | 5.06 |
| 14 | 23.00 | 2.06 | 16.25 | 20 | 1.25 | 20.25 | 14.14 | 13.25 | 16.75 | 14.00 | 2.94 | 5.56 |
| 16 | 25.50 | 2.19 | 18.50 | 20 | 1.38 | 22.50 | 16.16 | 15.25 | 19.00 | 16.00 | 3.19 | 5.69 |
| 18 | 28.00 | 2.31 | 21.00 | 24 | 1.38 | 24.75 | 18.18 | 17.25 | 21.00 | 18.00 | 3.44 | 6.19 |
| 20 | 30.50 | 2.44 | 23.12 | 24 | 1.38 | 27.00 | 20.20 | 19.25 | 23.12 | 20.00 | 3.69 | 6.32 |
| 22 | 33.00 | 2.57 | 25.25 | 24 | 1.63 | 29.25 | 22.22 | 21.25 | 25.25 | 22.00 | 3.93 | 6.43 |
| 24 | 36.00 | 2.69 | 27.62 | 24 | 1.63 | 32.00 | 24.25 | 23.25 | 27.62 | 24.00 | 4.13 | 6.56 |
ASME B16.5 Class 400 Flange Dimensions
Class 400 flanges are less common but specified in some refinery and process plant designs. Bore ID (WN) available on request. All dimensions in inches.
| NPS | OD | Min.T | RF Dia. | Bolt Holes | Hole Dia. | Bolt Circle | SO Bore | Hub Base | Hub Top | SO LTH | WN LTH |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/2 | 3.75 | 0.56 | 1.38 | 4 | 0.63 | 2.62 | 0.88 | 1.50 | 0.84 | 0.88 | 2.06 |
| 3/4 | 4.62 | 0.62 | 1.69 | 4 | 0.75 | 3.25 | 1.09 | 1.88 | 1.05 | 1.00 | 2.25 |
| 1 | 4.88 | 0.69 | 2.00 | 4 | 0.75 | 3.50 | 1.36 | 2.12 | 1.32 | 1.06 | 2.44 |
| 1-1/4 | 5.25 | 0.81 | 2.50 | 4 | 0.75 | 3.88 | 1.70 | 2.50 | 1.66 | 1.12 | 2.62 |
| 1-1/2 | 6.12 | 0.88 | 2.88 | 4 | 0.88 | 4.50 | 1.95 | 2.75 | 1.90 | 1.25 | 2.75 |
| 2 | 6.50 | 1.00 | 3.62 | 8 | 0.75 | 5.00 | 2.44 | 3.31 | 2.38 | 1.44 | 2.88 |
| 2-1/2 | 7.50 | 1.12 | 4.12 | 8 | 0.88 | 5.88 | 2.94 | 3.94 | 2.88 | 1.62 | 3.12 |
| 3 | 8.25 | 1.25 | 5.00 | 8 | 0.88 | 6.62 | 3.57 | 4.62 | 3.50 | 1.81 | 3.25 |
| 3-1/2 | 9.00 | 1.38 | 5.50 | 8 | 1.00 | 7.25 | 4.07 | 5.25 | 4.00 | 1.94 | 3.38 |
| 4 | 10.00 | 1.38 | 6.19 | 8 | 1.00 | 7.88 | 4.57 | 5.75 | 4.50 | 2.00 | 3.50 |
| 5 | 11.00 | 1.50 | 7.31 | 8 | 1.00 | 9.25 | 5.66 | 7.00 | 5.56 | 2.12 | 4.00 |
| 6 | 12.50 | 1.62 | 8.50 | 12 | 1.00 | 10.62 | 6.72 | 8.12 | 6.63 | 2.25 | 4.06 |
| 8 | 15.00 | 1.88 | 10.62 | 12 | 1.12 | 13.00 | 8.72 | 10.25 | 8.63 | 2.69 | 4.62 |
| 10 | 17.50 | 2.12 | 12.75 | 16 | 1.25 | 15.25 | 10.88 | 12.62 | 10.75 | 2.88 | 4.88 |
| 12 | 20.50 | 2.25 | 15.00 | 16 | 1.38 | 17.75 | 12.88 | 14.75 | 12.75 | 3.12 | 5.38 |
| 14 | 23.00 | 2.38 | 16.25 | 20 | 1.38 | 20.25 | 14.14 | 16.75 | 14.00 | 3.31 | 5.88 |
| 16 | 25.50 | 2.50 | 18.50 | 20 | 1.50 | 22.50 | 16.16 | 19.00 | 16.00 | 3.69 | 6.00 |
| 18 | 28.00 | 2.62 | 21.00 | 24 | 1.50 | 24.75 | 18.18 | 21.00 | 18.00 | 3.88 | 6.50 |
| 20 | 30.50 | 2.75 | 23.12 | 24 | 1.62 | 27.00 | 20.20 | 23.12 | 20.00 | 4.00 | 6.62 |
| 22 | 33.00 | 2.88 | 25.25 | 24 | 1.75 | 29.25 | 22.22 | 25.25 | 22.00 | 4.25 | 6.75 |
| 24 | 36.00 | 3.00 | 27.25 | 24 | 1.88 | 32.00 | 24.25 | 27.62 | 24.00 | 4.50 | 6.88 |
ASME B16.5 Class 600 Flange Dimensions
Class 600 flanges are widely used in high-pressure oil and gas and chemical processing applications. Covers all flange types including weld neck, slip-on, and blind. All dimensions in inches.
| NPS | OD | Min.T | RF Dia. | Bolt Holes | Hole Dia. | Bolt Circle | SO Bore | Hub Base | Hub Top | SO LTH | WN LTH |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/2 | 3.75 | 0.56 | 1.38 | 4 | 0.63 | 2.62 | 0.88 | 1.50 | 0.84 | 0.88 | 2.06 |
| 3/4 | 4.62 | 0.62 | 1.69 | 4 | 0.75 | 3.25 | 1.09 | 1.88 | 1.05 | 1.00 | 2.25 |
| 1 | 4.88 | 0.69 | 2.00 | 4 | 0.75 | 3.50 | 1.36 | 2.12 | 1.32 | 1.06 | 2.44 |
| 1-1/4 | 5.25 | 0.81 | 2.50 | 4 | 0.75 | 3.88 | 1.70 | 2.50 | 1.66 | 1.12 | 2.62 |
| 1-1/2 | 6.12 | 0.88 | 2.88 | 4 | 0.88 | 4.50 | 1.95 | 2.75 | 1.90 | 1.25 | 2.75 |
| 2 | 6.50 | 1.00 | 3.62 | 8 | 0.75 | 5.00 | 2.44 | 3.31 | 2.38 | 1.44 | 2.88 |
| 2-1/2 | 7.50 | 1.12 | 4.12 | 8 | 0.88 | 5.88 | 2.94 | 3.94 | 2.88 | 1.62 | 3.12 |
| 3 | 8.25 | 1.25 | 5.00 | 8 | 0.88 | 6.62 | 3.57 | 4.62 | 3.50 | 1.81 | 3.25 |
| 3-1/2 | 9.00 | 1.38 | 5.50 | 8 | 1.00 | 7.25 | 4.07 | 5.25 | 4.00 | 1.94 | 3.38 |
| 4 | 10.75 | 1.50 | 6.19 | 8 | 1.00 | 8.50 | 4.57 | 6.00 | 4.50 | 2.12 | 4.00 |
| 5 | 13.00 | 1.75 | 7.31 | 8 | 1.12 | 10.50 | 5.66 | 7.44 | 5.56 | 2.38 | 4.50 |
| 6 | 14.00 | 1.88 | 8.50 | 12 | 1.12 | 11.50 | 6.72 | 8.75 | 6.63 | 2.62 | 4.62 |
| 8 | 16.50 | 2.19 | 10.62 | 12 | 1.25 | 13.75 | 8.72 | 10.75 | 8.63 | 3.00 | 5.25 |
| 10 | 20.00 | 2.50 | 12.75 | 16 | 1.38 | 17.00 | 10.88 | 13.50 | 10.75 | 3.38 | 6.00 |
| 12 | 22.00 | 2.62 | 15.00 | 20 | 1.38 | 19.25 | 12.88 | 15.75 | 12.75 | 3.62 | 6.12 |
| 14 | 23.75 | 2.75 | 16.25 | 20 | 1.50 | 20.75 | 14.14 | 17.00 | 14.00 | 3.69 | 6.50 |
| 16 | 27.00 | 3.00 | 18.50 | 20 | 1.63 | 23.75 | 16.16 | 19.50 | 16.00 | 4.19 | 7.00 |
| 18 | 29.25 | 3.25 | 21.00 | 20 | 1.75 | 25.75 | 18.18 | 21.50 | 18.00 | 4.62 | 7.25 |
| 20 | 32.00 | 3.50 | 23.00 | 24 | 1.75 | 28.50 | 20.20 | 24.00 | 20.00 | 5.00 | 7.50 |
| 22 | 34.25 | 3.75 | 25.25 | 24 | 1.88 | 30.63 | 22.22 | 26.25 | 22.00 | 5.25 | 7.75 |
| 24 | 37.00 | 4.00 | 27.25 | 24 | 2.00 | 33.00 | 24.25 | 28.25 | 24.00 | 5.50 | 8.00 |
ASME B16.5 Class 900 Flange Dimensions
Class 900 flanges begin at NPS 3" (no 1/2" to 2-1/2" in Class 900). Used in high-pressure steam, gas, and process lines. WN bore ID (*) available on request. All dimensions in inches.
| NPS | OD | Min.T | RF Dia. | Bolt Holes | Hole Dia. | Bolt Circle | SO Bore | WN Bore | Hub Base | Hub Top | SO LTH | WN LTH |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 3 | 9.50 | 1.50 | 5.00 | 8 | 1.00 | 7.50 | 3.57 | * | 5.00 | 3.50 | 2.12 | 4.00 |
| 4 | 11.50 | 1.75 | 6.19 | 8 | 1.25 | 9.25 | 4.57 | * | 6.25 | 4.50 | 2.75 | 4.50 |
| 5 | 13.75 | 2.00 | 7.31 | 8 | 1.38 | 11.00 | 5.66 | * | 7.50 | 5.56 | 3.12 | 5.00 |
| 6 | 15.00 | 2.19 | 8.50 | 12 | 1.25 | 12.50 | 6.72 | * | 9.25 | 6.63 | 3.38 | 5.50 |
| 8 | 18.50 | 2.50 | 10.63 | 12 | 1.50 | 15.50 | 8.72 | * | 11.75 | 8.63 | 4.00 | 6.38 |
| 10 | 21.50 | 2.75 | 12.75 | 16 | 1.50 | 18.50 | 10.88 | * | 14.50 | 10.75 | 4.25 | 7.25 |
| 12 | 24.00 | 3.12 | 15.00 | 20 | 1.50 | 21.00 | 12.88 | * | 16.50 | 12.75 | 4.63 | 7.88 |
| 14 | 25.25 | 3.38 | 16.25 | 20 | 1.63 | 22.00 | 14.14 | * | 17.75 | 14.00 | 5.12 | 8.38 |
| 16 | 27.75 | 3.50 | 18.50 | 20 | 1.75 | 24.25 | 16.16 | * | 20.00 | 16.00 | 5.25 | 8.50 |
| 18 | 31.00 | 4.00 | 21.00 | 20 | 2.00 | 27.00 | 18.18 | * | 22.25 | 18.00 | 6.00 | 9.00 |
| 20 | 33.75 | 4.25 | 23.00 | 20 | 2.13 | 29.50 | 20.20 | * | 24.50 | 20.00 | 6.25 | 9.75 |
| 24 | 41.00 | 5.50 | 27.25 | 20 | 2.63 | 35.50 | 24.25 | * | 29.50 | 24.00 | 8.00 | 11.50 |
ASME B16.5 Class 1500 Flange Dimensions
Class 1500 flanges are specified for very high-pressure service, commonly in upstream oil and gas and high-pressure steam applications. All dimensions in inches.
| NPS | OD | Min.T | RF Dia. | Bolt Holes | Hole Dia. | Bolt Circle | SO Bore | Hub Base | Hub Top | SO LTH | WN LTH |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/2 | 4.75 | 0.88 | 1.38 | 4 | 0.88 | 3.25 | 0.88 | 1.50 | 0.84 | 1.25 | 2.38 |
| 3/4 | 5.12 | 1.00 | 1.69 | 4 | 0.88 | 3.50 | 1.09 | 1.75 | 1.05 | 1.38 | 2.75 |
| 1 | 5.88 | 1.12 | 2.00 | 4 | 1.00 | 4.00 | 1.36 | 2.06 | 1.32 | 1.62 | 2.88 |
| 1-1/4 | 6.25 | 1.12 | 2.50 | 4 | 1.00 | 4.38 | 1.70 | 2.50 | 1.66 | 1.62 | 2.88 |
| 1-1/2 | 7.00 | 1.25 | 2.88 | 4 | 1.12 | 4.88 | 1.95 | 2.75 | 1.90 | 1.75 | 3.25 |
| 2 | 8.50 | 1.50 | 3.63 | 8 | 1.00 | 6.50 | 2.44 | 4.12 | 2.38 | 2.25 | 4.00 |
| 2-1/2 | 9.62 | 1.62 | 4.13 | 8 | 1.12 | 7.50 | 2.94 | 4.88 | 2.88 | 2.50 | 4.12 |
| 3 | 10.50 | 1.88 | 5.00 | 8 | 1.25 | 8.00 | — | 5.25 | 3.50 | — | 4.62 |
| 4 | 12.25 | 2.12 | 6.19 | 8 | 1.38 | 9.50 | — | 6.38 | 4.50 | — | 4.88 |
| 5 | 14.75 | 2.88 | 7.31 | 8 | 1.63 | 11.50 | — | 7.75 | 5.56 | — | 6.12 |
| 6 | 15.50 | 3.25 | 8.50 | 12 | 1.50 | 12.50 | — | 9.00 | 6.63 | — | 6.75 |
| 8 | 19.00 | 3.62 | 10.63 | 12 | 1.75 | 15.50 | — | 11.50 | 8.63 | — | 8.38 |
| 10 | 23.00 | 4.25 | 12.75 | 12 | 2.00 | 19.00 | — | 14.50 | 10.75 | — | 10.00 |
| 12 | 26.50 | 4.88 | 15.00 | 16 | 2.12 | 22.50 | — | 17.75 | 12.75 | — | 11.12 |
| 14 | 29.50 | 5.25 | 16.25 | 16 | 2.38 | 25.00 | — | 19.50 | 14.00 | — | 11.75 |
| 16 | 32.50 | 5.75 | 18.50 | 16 | 2.63 | 27.75 | — | 21.75 | 16.00 | — | 12.25 |
| 18 | 36.00 | 6.38 | 21.00 | 16 | 2.88 | 30.50 | — | 23.50 | 18.00 | — | 12.88 |
| 20 | 38.75 | 7.00 | 23.00 | 16 | 3.12 | 32.75 | — | 25.25 | 20.00 | — | 14.00 |
| 24 | 46.00 | 8.00 | 27.25 | 16 | 3.63 | 39.00 | — | 30.00 | 24.00 | — | 16.00 |
ASME B16.5 Class 2500 Flange Dimensions
Class 2500 is the highest ASME B16.5 pressure class, limited to NPS 1/2" to NPS 12". Used in extreme pressure and temperature service conditions. All dimensions in inches.
| NPS | OD | Min.T | RF Dia. | Bolt Holes | Hole Dia. | Bolt Circle | Hub Base | Hub Top | SO LTH | WN LTH |
|---|---|---|---|---|---|---|---|---|---|---|
| 1/2 | 5.25 | 1.19 | 1.38 | 4 | 0.88 | 3.50 | 1.69 | 0.84 | 1.56 | 2.88 |
| 3/4 | 5.50 | 1.25 | 1.69 | 4 | 0.88 | 3.75 | 2.00 | 1.05 | 1.69 | 3.12 |
| 1 | 6.25 | 1.38 | 2.00 | 4 | 1.00 | 4.25 | 2.25 | 1.32 | 1.88 | 3.50 |
| 1-1/4 | 7.25 | 1.50 | 2.50 | 4 | 1.12 | 5.13 | 2.88 | 1.66 | 2.06 | 3.75 |
| 1-1/2 | 8.00 | 1.75 | 2.88 | 4 | 1.25 | 5.75 | 3.12 | 1.90 | 2.38 | 4.38 |
| 2 | 9.25 | 2.00 | 3.63 | 8 | 1.12 | 6.75 | 3.75 | 2.38 | 2.75 | 5.00 |
| 2-1/2 | 10.50 | 2.25 | 4.13 | 8 | 1.25 | 7.75 | 4.50 | 2.88 | 3.12 | 5.62 |
| 3 | 12.00 | 2.62 | 5.00 | 8 | 1.38 | 9.00 | 5.25 | 3.50 | — | 6.62 |
| 4 | 14.00 | 3.00 | 6.19 | 8 | 1.63 | 10.75 | 6.50 | 4.50 | — | 7.50 |
| 5 | 16.50 | 3.62 | 7.31 | 8 | 1.88 | 12.75 | 8.00 | 5.56 | — | 9.00 |
| 6 | 19.00 | 4.25 | 8.50 | 8 | 2.12 | 14.50 | 9.25 | 6.63 | — | 10.75 |
| 8 | 21.75 | 5.00 | 10.63 | 12 | 2.12 | 17.25 | 12.00 | 8.63 | — | 12.50 |
| 10 | 26.50 | 6.50 | 12.75 | 12 | 2.63 | 21.25 | 14.75 | 10.75 | — | 16.50 |
| 12 | 30.00 | 7.25 | 15.00 | 12 | 2.88 | 24.38 | 17.38 | 12.75 | — | 18.25 |
ASME B16.5 Flange Size Chart
The ASME B16.5 flange size chart below shows nominal pipe size (NPS) to DN equivalents and key dimensional reference points used across all pressure classes.
| NPS | DN | Common Classes | Common Types |
|---|---|---|---|
| 1/2 to 2 | 15 to 50 | 150, 300, 600, 1500, 2500 | WN, SO, SW, TH, BL |
| 2-1/2 to 12 | 65 to 300 | 150, 300, 400, 600, 900, 1500, 2500 | WN, SO, BL, LJ, Reducing |
| 14 to 24 | 350 to 600 | 150, 300, 400, 600, 900, 1500 | WN, SO, BL, LJ |
| 26 to 48 | 650 to 1200 | ASME B16.47 on request | Large diameter flanges |
ASME B16.5 Flange Tolerances
All ASME B16.5 flanges supplied by Amardeep Steel conform to the following ASME B16.5 dimensional tolerances per Table 7 of the standard:
| Tolerance Parameter | Permissible Deviation |
|---|---|
| Flange Thickness (T) - NPS <= 18" | +3.0 mm / -0.0 mm |
| Flange Thickness (T) - NPS >= 20" | +5.0 mm / -0.0 mm |
| Raised Face OD (2.0 mm RF) | +/-1.0 mm |
| Raised Face OD (7.0 mm RF) | +/-0.5 mm |
| Flange Face Perpendicularity - NPS <= 5" | +/-1 degree |
| Flange Face Perpendicularity - NPS >= 6" | +/-0.5 degree |
| Welding End OD - NPS <= 5" | +2.0 mm / -1.0 mm |
| Welding End OD - NPS >= 6" | +4.0 mm / -1.0 mm |
| Bore (Slip-On & Lapped) - NPS <= 10" | +1.0 mm / -0.0 mm |
| Bore (Slip-On & Lapped) - NPS >= 12" | +1.5 mm / -0.0 mm |
| Center-to-Contact Surface - NPS <= 10" | +/-1.0 mm |
| Center-to-Contact Surface - NPS >= 12" | +/-1.5 mm |
Full tolerance tables per ASME B16.5 Table 7 are available on request from our technical team.
ASME B16.5 Flange Pressure-Temperature Ratings - Class 150 to 2500 (PSIG)
The table below shows maximum allowable non-shock working pressure (PSIG) for Group 1.1 material (A105 Carbon Steel) across all ASME B16.5 pressure classes and temperature ranges.
| Temperature F | Class 150 | Class 300 | Class 400 | Class 600 | Class 900 | Class 1500 | Class 2500 |
|---|---|---|---|---|---|---|---|
| -20 to 100 | 285 | 740 | 985 | 1480 | 2220 | 3705 | 6170 |
| 200 | 260 | 680 | 905 | 1360 | 2035 | 3395 | 5655 |
| 300 | 230 | 655 | 870 | 1310 | 1965 | 3270 | 5450 |
| 400 | 200 | 635 | 845 | 1265 | 1900 | 3170 | 5280 |
| 500 | 170 | 605 | 805 | 1205 | 1810 | 3015 | 5025 |
| 600 | 140 | 570 | 755 | 1135 | 1705 | 2840 | 4730 |
| 650 | 125 | 550 | 730 | 1100 | 1650 | 2745 | 4575 |
| 700 | 110 | 530 | 710 | 1060 | 1590 | 2655 | 4425 |
| 750 | 95 | 505 | 675 | 1015 | 1520 | 2535 | 4230 |
| 800 | 80 | 410 | 550 | 825 | 1235 | 2055 | 3430 |
| 850 | 65 | 320 | 425 | 535 | 640 | 955 | 2655 |
| 900 | 50 | 230 | 305 | 460 | 690 | 1150 | 1915 |
| 950 | 35 | 135 | 185 | 275 | 410 | 685 | 1145 |
| 1000 | 20 | 85 | 115 | 170 | 255 | 430 | 715 |
ASME B16.5 Flange Suppliers in India
Amardeep Steel Centre supplies ASME B16.5 Flanges across all major industrial cities in India including Mumbai, Delhi, Kolkata, Chennai, Hyderabad, Ahmedabad, Bangalore, Pune, Surat, Lucknow, Nagpur, Visakhapatnam, Nashik, Coimbatore, Vadodara, Bhubaneswar, Ludhiana, Jalandhar, Amritsar, Chandigarh, Jaipur, Indore, Bhopal, Gwalior, Jabalpur, Raipur, Bhilai, Durgapur, Asansol, Siliguri, Jamshedpur, Patna, Ranchi, Kochi, Kozhikode, Mangalore, Guwahati, and all Union Territories across India.
ASME B16.5 Flange Export Destinations
Amardeep Steel exports ASME B16.5 Flanges to 65+ countries worldwide including the United States of America, United Kingdom, United Arab Emirates, Saudi Arabia, Qatar, Oman, Kuwait, Iraq, Iran, Germany, France, Italy, Spain, Netherlands, Belgium, Norway, Sweden, Denmark, Finland, Poland, Czechia, Romania, Ukraine, Russia, Turkey, Malaysia, Singapore, Indonesia, Thailand, South Korea, Japan, Vietnam, Philippines, Australia, New Zealand, South Africa, Nigeria, Ghana, Egypt, Morocco, Algeria, Tunisia, Brazil, Mexico, Argentina, Chile, Peru, Colombia, Venezuela, Canada, and more.
Related Flange Products
Looking for specialized flanges or alternative standards? Explore our complete range:
By Standard
Frequently Asked Questions
What is the difference between ASME B16.5 and ASME B16.47?
ASME B16.5 covers flanges in sizes NPS 1/2" to NPS 24". ASME B16.47 covers large-diameter flanges in sizes NPS 26" to NPS 60" in Series A (MSS SP-44) and Series B (API 605).
What pressure classes does ASME B16.5 cover?
ASME B16.5 defines seven pressure classes: Class 150, 300, 400, 600, 900, 1500, and 2500. Class 2500 is limited to NPS 1/2" to NPS 12".
What materials are permitted under ASME B16.5?
ASME B16.5 permits carbon steel (A105, A350), alloy steel (A182 F5-F91), stainless steel (A182 F304/316), and non-ferrous alloys. Plate materials are permitted only for blind and reducing flanges without hubs.
What is the correct ASME B16.5 flange marking?
Each flange must show manufacturer name, material grade, pressure class, B16.5 conformance, NPS size, and heat number. RTJ flanges additionally require the R mark and groove number per MSS SP-25.
What is the difference between Class 150 and Class 300 flanges?
Class 300 flanges have thicker bodies, larger bolt circles, and higher working pressure ratings than Class 150 at any given temperature. For example, at 100 degF in A105 steel: Class 150 = 285 PSIG vs Class 300 = 740 PSIG.
What is the maximum size for ASME B16.5 flanges?
ASME B16.5 covers flanges up to NPS 24" (DN 600). Amardeep Steel can also supply larger flanges up to NPS 48" per ASME B16.47; contact us for availability.
