Stainless Steel Threaded Flange

S&S Stainless International, a leading stainless steel flange manufacturer, supplies high-quality stainless steel threaded flanges compliant with ASME B16.5 standards. Featuring internal threads, these stainless steel flanges are designed to screw onto externally threaded pipes, eliminating the need for welding. This makes them ideal for applications where welding is impractical or undesirable. Commonly used in low-pressure and low-temperature systems, these stainless steel flanges are also suited for environments requiring non-permanent connections. Trust S&S Stainless International for reliable, precision-engineered flange solutions tailored to your needs.

What is a Threaded Flange?

A stainless steel threaded flange, compliant with ASME B16.5, is an ideal solution for low-pressure and low-temperature systems where welding isn’t feasible. Its internal threads allow for secure and straightforward installation by screwing onto external pipe threads, making it perfect for applications requiring non-permanent connections or frequent disassembly. This flange type is commonly used with smaller-diameter pipes and provides reliable performance in systems with moderate operational demands. Choose S&S Stainless International for durable, high-quality threaded flanges tailored to diverse industrial needs.

Product Overview of Stainless Steel Threaded Flange

  • Design of Threaded Flange
    • The stainless steel threaded flange has a tapered threaded bore to match the external threads of the pipe.
    • Available Sealing Surface: Raised Face(RF), and Flat Face(FF).
  •  Material of Threaded Flange

    • Constructed from premium ASTM A182 stainless steel grades like 304 and 316, the stainless steel threaded flange resists corrosion, rust, oxidation, and chemical damage, ensuring long-term durability.

  •  Pressure Ratings of Threaded Flange
    • Available in ASME B16.5 lower pressure classes such as 150, 300, and 600, making the threaded flange suitable for demanding applications.
  •   Non-Welded Connection of Threaded Flange
    • The threaded flange is screwed directly onto the pipe without the need for welding, making the installation quick and easy.
  •  

Stainless Steel Threaded Flange Dimensions

ASME B16.5

ASME B16.5 stainless steel blind flange dimension chart, covering pressure classes from 150 to 600.

Nominal Diameter Pipe Diameter O.D.of Flange Diameter of Raised Face Diameter of Bolt Holes Circle Diameter of Bolt Holes Numbers of Bolt Holes Diameter of Bolt Holes(inch) Flange Thickness Hub Diameter Through Hub Length (H)
DN NPS ID D G, R K L B1-B4 A H1 H2 H3
15 ½’’ 21.3 90 35 60.5 16 4 M14 11.5 30 48 16 16
20 ¾’’ 26.9 100 43 70 16 4 M14 13 38 52 16 16
25 1’’ 33.7 110 51 79.5 16 4 M14 14.5 49 56 17 17
32 1 ¼’’ 42.4 120 63.5 89 16 4 M14 16 59 57 21 21
40 1 ½’’ 48.3 130 73 98.5 16 4 M14 17.5 65 62 22 22
50 2’’ 60.3 150 92 120.5 18 4 M16 19.5 78 64 25 25
65 2 ½’’ 76.1 180 105 139.5 18 4 M16 22.5 90 70 29 29
80 3’’ 88.9 190 127 152.5 18 4 M16 24 108 70 30 30
90 3 ½’’ 101.6 216 140 178 18 8 M20 24 122 71 - 32
100 4’’ 114.3 230 157.5 190.5 18 8 M20 24 135 76 33 33
125 5’’ 139.7 255 186 216 22 8 M20 24 164 89 36 36
150 6’’ 168.3 280 216 241.5 22 8 M20 25.5 192 89 40 40
200 8’’ 219.1 345 270 298.5 22 8 M20 29 246 102 44 45
250 10'’ 273 405 324 362 26 12 M24 30.5 305 102 49 49
300 12'’ 323.9 485 381 432 26 12 M24 32 365 114 56 56
350 14'’ 355.6 535 413 476 29.5 12 M27 35 400 127 57 79
400 16'’ 406.4 600 470 540 29.5 16 M27 37 457 127 64 87
450 18'’ 457 635 533.5 578 32.5 16 M30 40 505 140 68 97
500 20'’ 508 700 584 635 32.5 20 M30 43 559 145 73 103
550 22'’ 559 750 641 692 35.5 20 M33 46 610 149 - -
600 24'’ 610 816 692 749.5 35.5 20 M33 48 664 152 83 111
Nominal Diameter Pipe Diameter O.D. of Flange Diameter ofRaised Face Diameter of Bolt Holes Circle Diameter ofBolt Holes Numbers ofBoltHoles Diameter of Bolt Holes(inch) Flange Thickness Hub Diameter Through Hub Length
DN NPS ID D G, R K L B1-B4 A H1 H2 H3
15 ½’’ 21.3 95 35 66.5 16 4 M14 14.5 38 52 22 22
20 ¾’’ 26.9 120 43 82.5 18 4 M16 16 48 57 25 25
25 1’’ 33.7 125 51 89 18 4 M16 17.5 54 62 27 27
32 1 ¼’’ 42.4 135 63.5 98.5 18 4 M16 19.5 64 65 27 27
40 1 ½’’ 48.3 155 73 114.5 22 4 M20 21 70 68 30 30
50 2’’ 60.3 165 92 127 18 8 M16 22.5 84 70 33 33
65 2 ½’’ 76.1 190 105 149 22 8 M20 25.5 100 76 38 38
80 3’’ 88.9 210 127 168.5 22 8 M20 29 118 79 43 43
90 3 ½’’ 101.6 229 140 184 22 8 M20 30 140 81 45 45
100 4’’ 114.3 255 157.5 200 22 8 M20 32 146 86 48 48
125 5’’ 139.7 280 186 235 22 8 M20 35 178 98 51 51
150 6’’ 168.3 320 216 270 22 12 M20 37 206 98 52 52
200 8’’ 219.1 380 270 330 26 12 M24 41.5 260 111 62 62
250 10'’ 273 445 324 387.5 29.5 16 M27 48 321 117 67 95
300 12'’ 323.9 520 381 451 32.5 16 M30 51 275 130 73 102
350 14'’ 355.6 585 413 514.5 32.5 20 M30 54 426 143 76 111
400 16'’ 406.4 650 470 571.5 32.5 20 M33 57.5 483 146 83 121
450 18'’ 457 710 533.5 628.5 32.5 24 M33 60.5 533 159 89 130
500 20'’ 508 775 584 686 32.5 24 M33 63.5 587 162 95 140
550 22'’ 559 840 641 743 42 24 M39 66.5 640 165 - -
600 24'’ 610 915 692 813 42 24 M39 70 702 168 104 152
Nominal Diameter Pipe Diameter O.D. of Flange Diameter of Raised Face Diameter of Bolt Holes Circle Diameter of Bolt Holes Numbers of Bolt Holes Diameter of Bolt Holes(inch) Flange Thickness Hub Diameter Through Hub Length
DN NPS ID D G, R K L B1-B4 A H1 H2 H3
15 ½’’ 21.3 95 35 66.5 16 4 M14 14.5 38 52 22 22
20 ¾’’ 26.9 120 43 82.5 18 4 M16 16 48 57 25 25
25 1’’ 33.7 125 51 89 18 4 M16 17.5 54 62 27 27
32 1 ¼’’ 42.4 135 63.5 98.5 18 4 M16 21 64 67 29 29
40 1 ½’’ 48.3 155 73 114.5 22 4 M20 22.5 70 70 32 32
50 2’’ 60.3 165 92 127 18 8 M16 22.5 84 73 37 37
65 2 ½’’ 76.1 190 105 149 22 8 M20 29 100 79 41 41
80 3’’ 88.9 210 127 168.5 22 8 M20 32 117 83 46 46
90 3 ½’’ 101.6 229 140 184 26 8 M24 35 133 86 49 49
100 4’’ 114.3 275 157.5 216 26 8 M24 38.5 152 102 54 54
125 5’’ 139.7 330 186 267 29.5 8 M27 44.5 189 114 60 60
150 6’’ 168.3 355 216 292 29.5 12 M27 48 222 117 67 67
200 8’’ 219.1 420 270 349 32.5 12 M30 55.5 273 133 76 76
250 10'’ 273 510 324 432 35.5 16 M33 63.5 343 152 86 111
300 12'’ 323.9 560 381 489 35.5 20 M33 67 400 156 92 117
350 14'’ 355.6 605 413 527 39 20 M36 70 432 165 94 127
400 16'’ 406.4 685 470 603 42 20 M39 76.5 495 178 106 140
450 18'’ 457 745 533.5 654 45 20 M42 83 546 184 117 152
500 20'’ 508 815 584 724 45 24 M42 89 610 190 127 165
550 22'’ 559 870 641 778 48 24 M45 95 665 197 - -
600 24'’ 610 940 692 838 51 24 M48 102 718 203 140 184

Navigating Our Threaded Flange Dimension Table

This table provides detailed measurements for selecting the correct stainless steel threaded flange. You will find dimensions for:

  • Nominal Pipe Size (NPS): The standard pipe size for which the flange is designed.
  • Outside Diameter (OD) of Flanges: The total diameter of the flange itself.
  • Raised Face (RF) Height: The height of the raised portion of the flange sealing surface (if applicable).
  • Bolt Circle Diameter (BCD): The diameter on which the centers of the bolt holes lie.
  • Number of Bolts & Bolt Hole Diameter: Specifies the quantity and size of bolts required for connection.
  • Flange Thickness (T): The overall thickness of the flange.
  • Hub Diameter: The diameter of the cylindrical or tapered projection from the flange.
  • Through Hub Length: The length of the hub from the flange face to its end, indicating how far the pipe will extend into the flange.

Carefully match these dimensions to your project’s requirements to ensure a secure and leak-proof connection.

Custom Stainless Steel Flange by S&S Stainless International

S&S Stainless International specializes in precision-engineered custom stainless steel flanges tailored strictly to customer-provided technical drawings and unique operational specifications. Designed to solve complex cross-standard alignment challenges, our advanced forging and machining capabilities allow us to seamlessly combine ASME/ANSI, JIS, and EN 1092-1 standards—such as blending ASME bolt circles with EN sealing faces or JIS pressure dimensions—to deliver a 100% exact match for hybrid or legacy pipeline systems.

FAQs

1. What are the main advantages of using a threaded flange, and in what applications are they recommended?

Threaded flanges (also known as screwed flanges) feature an internal NPT or BSPT female thread that connects directly to externally threaded pipe without requiring welding. This makes them ideal for low-pressure, ambient-temperature piping systems, highly volatile or explosive environments where welding poses a fire hazard, and compact spaces where field welding equipment cannot be operated.

We supply forged stainless steel threaded flanges with precision-machined NPT (ANSI/ASME B1.20.1) or BSPT (ISO 7-1) female threads per ASME B16.5 specifications. Available in Class 150 and Class 300 pressure ratings (as well as PN10/PN16 per EN 1092-1), our threaded flanges can be ordered in Raised Face (RF) or Flat Face (FF) configurations in dual-certified ASTM A182 F304/304L and F316/316L material grades.

Every production batch undergoes strict thread pitch and depth checks using precision NPT/BSPT go/no-go plug gauges to guarantee smooth, leak-tight field assembly. Our QC team conducts 100% Positive Material Identification (PMI) chemical analysis, visual hub inspections, and dimensional verification. All shipments are solution annealed and supplied with EN 10204 3.1 Material Test Reports (MTRs) with Third-Party Inspection (TPI) support.

Standard factory manufacturing lead time is 30 to 45 days after order confirmation and drawing verification. We offer flexible MOQs for standard sizes (1/2″ to 24″), allowing international procurement managers to combine threaded flanges with weld neck flanges, slip-on flanges, blind flanges, and pipe fittings into a single consolidated container order to optimize freight costs.

To prevent thread damage, thread galling, or sealing face deformation during long-distance transit, all female threads are fitted with heavy-duty plastic threaded plugs, and flange faces are coated with rust-inhibiting oil and capped with plastic covers. Items are stacked with cardboard dividers inside seaworthy wooden cases lined with waterproof plastic film. We support flexible trade terms including EXW, FOB, CFR, CIF, and DDP via sea or air freight.

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Request a quote for stainless steel threaded flanges with your size, grade, and quantity.

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