UNS C84400 Bronze Flanges Manufacturer & Exporter
C84400 is a leaded semi-red brass known as valve composition, or 81-3-7-9. It is a free-machining, economical casting alloy for valve, fitting and general plumbing flanges.
UNS C84400 at a glance
- Leaded semi-red brass: nominal 81 Cu - 3 Sn - 7 Pb - 9 Zn
- Cast to ASTM B584
- Machinability rating 90 — the highest of the grades on this site
- Leaded: not for potable-water wetted parts
Material Overview and Designation
Designation and classification
UNS C84400| Item | Detail |
|---|---|
| UNS designation | C84400 |
| Common names | Valve composition; 81-3-7-9; leaded semi-red brass |
| Alloy family | Cast copper-zinc-tin-lead (leaded semi-red brass) |
| Casting specification | ASTM B584 (sand castings for general applications) |
| Nominal composition | 81 Cu - 3 Sn - 7 Pb - 9 Zn |
Chemical Composition
Chemical composition (weight %)
SM-CHEM-C84400| Element | Range, % |
|---|---|
| Copper (Cu) | 78.0 – 82.0 |
| Tin (Sn) | 2.3 – 3.5 |
| Lead (Pb) | 6.0 – 8.0 |
| Zinc (Zn) | 7.0 – 10.0 |
| Nickel, iron, antimony, sulfur, phosphorus, aluminium, silicon | Residual limits per ASTM B584 |
Principal-element ranges, weight %, per ASTM B584. Confirm against the edition named in your purchase order.
Mechanical Properties
Mechanical properties: ksi (MPa)
SM-MECH-C84400| Condition / specification | Tensile, min | Yield, min | Elongation, min % |
|---|---|---|---|
| Typical reference value (as cast) | ≈36 (≈250) | ≈14 (≈95) | Varies with section |
| Minimum values | Set in ASTM B584 for the edition on your order | – | – |
Values are specification minimums or typical reference data and depend on product form, casting method and condition. Acceptance values are those in the specification and purchase order that apply to your order. Minimum values are taken from the edition of ASTM B584 named on the purchase order.
Physical and Fabrication Properties
Physical and fabrication data
SM-PHYS-C84400| Property | Value |
|---|---|
| Machinability rating | 90 (CDA scale, free-cutting brass C36000 = 100) |
| Brinell hardness, typical | ≈50 – 60 (500 kg load) |
Physical and fabrication values are published reference data (CDA / producer data sheets). Machinability: free-cutting brass C36000 = 100.
Corrosion Characteristics and Service
C84400 resists atmospheric exposure and fresh water and performs well in general valve and plumbing duty at moderate pressure and temperature. Its zinc content is higher than that of C83600, so resistance to selective leaching (dezincification) should be reviewed for aggressive or stagnant water.
As a leaded alloy it is not specified for potable-water wetted components under U.S. lead-free requirements. Seawater, ammonia-bearing media and oxidizing acids are better served by other alloys.
Manufacturing and Machining
C84400 is the most freely machining alloy on this site. Short chips and low cutting forces mean fast cycle times, good finish on gasket faces and economical flange production. It is cast to ASTM B584 and is commonly supplied as sand-cast blanks.
As with other leaded copper alloys, joining to pipe is by brazing or soldering rather than fusion welding.
UNS C84400 Flanges and Applications
C84400 flanges are used for valve and fitting connections, plumbing and general low-pressure piping where economy and fast machining are priorities and leaded alloys are acceptable. The common style is the threaded flange, with slip-on, blind and reducing flanges available.
Flange types in UNS C84400
SM-FLG-C84400| Flange type | Notes |
|---|---|
| Threaded / Screwed Flanges | Common valve and fitting flange style |
| Blind Flanges | Low-pressure closures |
| Reducing Flanges | Valve-side adaptors |
| Slip-On Flanges | Brazed pipework connections |
- Valve end connections
- Pipe fittings and plumbing flanges (non-potable)
- General industrial low-pressure service
- Pump and utility piping
Inspection and Documentation
Material is verified against UNS C84400 and the ASTM B584 edition on the order, with an MTC where required. Dimensional inspection covers OD, thickness, bore or thread, PCD and hole pattern, and visual examination checks gasket faces. Other tests are carried out only when listed on the purchase order.
Applicable Standards
Applicable standards
SM-STD-C84400| Standard | Scope |
|---|---|
| ASTM B584 | Copper alloy sand castings for general applications |
| ASTM B30 | Copper-base alloys in ingot form |
| ASME B16.24 | Cast copper alloy pipe flanges and flanged fittings, where applicable |
| MSS SP-106 | Cast copper alloy flanges and flanged fittings, where applicable |
| MSS SP-25 | Standard marking system for valves, fittings, flanges and unions |
The edition and specification on your purchase order govern. Listing a standard here does not imply approval or certification to it.
UNS C84400: common questions
What is C84400 valve composition?
C84400 is a leaded semi-red brass with a nominal 81 percent copper, 3 percent tin, 7 percent lead and 9 percent zinc, cast to ASTM B584.
How machinable is C84400?
It has a CDA machinability rating of 90, the highest of the seven grades we supply, which keeps cycle times short on flange machining.
Why is C84400 not used for potable water?
It is a leaded alloy, and U.S. lead-free requirements restrict leaded alloys for drinking-water wetted parts.
Related Information
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