Phosphorous Bronze Fasteners
UNS C54400 / C51000 Phosphor Bronze Hex Bolts, Screws, Nuts & Washers Supplier
Excellent Fatigue Resistance, Superior Spring Properties, and Seawater Corrosion Protection
Product Overview
Kuldevi Forge & Fittings is a leading manufacturer and supplier of premium **Phosphorous Bronze Fasteners** (copper-tin-phosphorous alloy). Conforming to high-grade standards including **UNS C54400**, **C51000**, and **C51900**, our phosphor bronze bolts, nuts, and spring washers are engineered specifically for applications demanding low coefficient of friction, high elasticity, and outstanding fatigue limits.
Phosphor bronze alloys typically contain copper remainder, 3.5% to 10% tin, and up to 0.5% phosphorus. The tin content boosts overall corrosion resistance and tensile strength, while phosphorus acts as a deoxidizing agent during melting, which significantly increases wear resistance and stiffness. These attributes make phosphor bronze bolts highly sought after for electrical connectors, spring components, marine propeller shafts, valve components, and heavy-duty industrial machinery.
Our production capabilities include CNC machined fasteners up to M100 (4" diameter) and 1500mm length, and hot-forged Phosphor Bronze Hex Screws up to M36 (1-1/2" diameter) and 1100mm length. These fasteners demonstrate superior resistance to chemical environments, organic acids, and marine seawater environments compared to conventional brass bolting systems.
Standard Specifications
| Fasteners Standard | IS, GB, BS, ASME, ANSI, DIN, ASTM, JIS, UNI, ISO and all International Standards |
|---|---|
| Material Specifications | ASTM B139 | UNS C54400, C51000, C51100, C51900, C52100 (CDA 510, 544) |
| Bolt / Screw Size | M2 to M160 | 1/4" to 2" | Custom Sizes up to 4" (M100) |
| Thread Requirements | UNC, UNF, UNEF, UNS, NPT, BSW, BSF, Metric Coarse, Metric Fine |
| ASME Nut Standards | ASME B18.2.2 (Hex Nuts) | ANSI B18.2.4.1M & B18.2.4.2M |
| Stud Length Standards | ASME B16.5 (Stud Bolts) | Threading as per high-precision gauges |
| Available Forms | Hex Bolts, Hex Screws, Spring Washers, Flat Washers, Thrust Washers, Heavy Hex Nuts, Continuous Threaded Rods, Stud Bolts, Slotted Screws, Phillips Head Screws, Round, Square, and Custom Forgings |
Equivalent Grades
| CDA / UNS | ASTM Standard | SAE Standard |
|---|---|---|
| C54400 (Free-cutting Phos Bronze) | ASTM B139 | SAE J461 / SAE J463 |
| C51000 (510 Phos Bronze) | ASTM B139 / B505 | SAE J461 / SAE J463 |
| C51900 | ASTM B139 | SAE J463 |
DIN and ISO Designations
Standards references mapped to equivalent international designations.
| Form | DIN Standard | ISO Standard |
|---|---|---|
| Hex Nuts | DIN 934 / DIN 970 | ISO 4032 / ISO 4033 |
| Hex Screws / Bolts | DIN 931 / DIN 933 | ISO 4014 / ISO 4017 |
| Threaded Rods | DIN 975 / DIN 976 | Standard metric rods |
Chemical Composition (UNS C54400)
| Element | Composition percentage (%) |
|---|---|
| Copper (Cu) | Remainder |
| Tin (Sn) | 3.50 - 4.50% |
| Lead (Pb) | 3.00 - 4.00% |
| Zinc (Zn) | 1.50 - 4.50% |
| Iron (Fe, max) | 0.10% |
| Phosphorus (P) | 0.01 - 0.50% |
Mechanical Properties (UNS C54400)
| Property Name | Value (Imperial) | Value (Metric) |
|---|---|---|
| Tensile Strength (min) | 60 KSI | 415 MPa |
| Elongation in 2 in / 50 mm (min) | 10 % | 10 % |
| Machinability Rating | 80 % (Free Cutting) | 80 % (Free Cutting) |
Physical Properties (Phosphor Bronze Alloys)
| Physical Parameter | Value |
|---|---|
| Density (g/cm³) | 8.89 |
| Melting Temperature Range (°C) | 920 - 1000 °C |
| Thermal Conductivity (W/mK) | 86.5 W/mK |
| Electrical Resistivity (μΩ.m @ 15°C) | 9.0 μΩ.m |
| Coefficient of Thermal Expansion (0-250°C, per °C x 10^-6) | 17.3 |
| Relative Magnetic Permeability | < 1.01 (Virtually Non-magnetic) |
Tightening Torque Chart (Phosphor Bronze Screws)
Target torque values (ft-lbs) for spring socket cap screws under dry and lubricated installation states.
| Nominal Diameter (in) | TPI (Threads Per Inch) | Tightening Torque (ft-lb, Dry) | Tightening Torque (ft-lb, Lubricated) |
|---|---|---|---|
| 1/4″ | 20 TPI (Coarse) | 6.5 | 4.8 |
| 28 TPI (Fine) | 7.4 | 5.5 | |
| 5/16″ | 18 TPI (Coarse) | 13.2 | 10.0 |
| 24 TPI (Fine) | 14.7 | 11.0 | |
| 3/8″ | 16 TPI (Coarse) | 23.5 | 17.6 |