Threaded / Screwed Bronze Flanges Manufacturer & Exporter
Threaded flanges connect to pipe through an internal thread, avoiding welding at the joint. Bronze and gunmetal are well suited because they machine cleanly and hold thread form.
What is a Threaded flange?
A threaded or screwed flange is bored and internally threaded so that threaded pipe screws directly into it. The joint is made mechanically, which suits installations where hot work is restricted, where the pipe material is not easily welded to the flange, or where the line may need to be dismantled.
Thread quality drives the integrity of the joint. Because bronze machines well, threads can be cut accurately and consistently; free-cutting grades such as C83600, C93200 and C84400 are the usual choices for this flange type. Thread form (for example NPT or BSP) must be specified when ordering, since the two are not interchangeable.
Construction
- Internally threaded bore, tapered or parallel as specified
- Optional hub to give thread engagement length
- Flat or raised face, per standard
- Bolt-hole pattern to the specified standard or drawing
- Chamfer or relief at thread entry as required
Values vary according to applicable specification, material condition and customer requirements.
Threaded Bronze Flanges — specification
| Connection | Internal thread — NPT, BSP or other specified form |
|---|---|
| Thread inspection | Gauged to the thread standard named in the order |
| Facing | Flat face / raised face / custom |
| Pressure class | As defined by the applicable standard; limited by thread joint design |
| Sizes | As per customer requirement / applicable standard |
| Pressure classes | Pressure classes and pressure-temperature ratings are defined by the standard applied and depend on alloy and temperature. Available as per applicable material and dimensional standard. |
| Facing options | Flat face (FF), raised face (RF) or custom facing as specified by the standard or drawing. |
| Standards | Typical reference standards for copper-alloy flanges include ASME B16.24 (cast copper alloy pipe flanges and flanged fittings), MSS SP-106 (cast copper alloy flanges and flanged fittings) and EN 1092-3 (copper alloy flanges). Customer drawings and other national or project standards are also worked to. The standard to be applied is confirmed when the enquiry is reviewed. |
|---|---|
| Dimensions | Outside diameter, thickness, bore, bolt-circle diameter, number and size of holes per the standard or customer drawing. Available as per applicable material and dimensional standard. |
Available bronze materials
Available as per applicable material and dimensional standard. Select a grade for composition limits, mechanical properties and corrosion notes.
| UNS grade | Alloy family | Note |
|---|---|---|
| UNS C83600 | Leaded red brass / composition bronze (Cu-Sn-Pb-Zn) | UNS C83600 — commonly called gunmetal, composition bronze or red bronze — is the traditional general-purpose cast alloy for valves, pump parts and pipe fittings, and the material behind our gunmetal flanges. |
| UNS C93200 | Leaded tin bronze (Cu-Sn-Pb-Zn) | UNS C93200 is a leaded tin bronze widely used where free machining, good pressure tightness in castings and bearing behaviour matter more than very high strength. |
| UNS C84400 | Leaded semi-red brass (Cu-Zn-Pb-Sn) | UNS C84400 is a leaded semi-red brass, often called valve composition, used extensively for valves, plumbing and general fittings where free machining and economy matter. |
| UNS C95400 | Aluminium bronze (Cu-Al-Fe) | UNS C95400 is a heat-treatable aluminium bronze that combines high strength with good wear and corrosion performance, making it a common choice for demanding pump, valve and marine components. |
Where these flanges are used
- Plumbing and utility water lines
- Low-pressure process and cooling lines
- Fire-protection and service piping where permitted by the system code
- Pump, strainer and instrument connections
See also: Water Treatment · HVAC · Industrial Piping.
Inspection and testing
- Thread gauging against specified standard
- Bore diameter and thread depth
- Face flatness and finish
- Hole pattern (PCD) and bolt-hole size
- Material identification and documents as agreed (MTC, inspection report, as applicable)
Made to your specification
Special thread forms, sizes, thread lengths and hub dimensions can be produced to drawing. Please state the thread standard in your enquiry.
For non-standard dimensions, see custom & special flanges.
Related flange types
- Blind FlangesBlind flanges are solid discs used to close the end of a pipe, valve or pressure vessel nozzle.
- Plate FlangesPlate flanges are flat rings with a bore and a bolt-hole pattern.
- Custom / Special FlangesSend your drawing, sample or specification.
Have a Bronze Flange Requirement?
Send us your drawing, specification, material grade, size and quantity.