Alloy SteelBar/Rod
Description (English)
Q1: What is Waukesha Metal 88 / Alloy 88? Alloy 88 (Waukesha Metal 88, "WM88") is a nickel-base anti-galling alloy patented by Waukesha Foundry in 1954 and standardised as ASTM A494 Grade CY5SnBiM (UNS N26055). Its bismuth and tin additions form self-lubricating phases in the microstructure, so parts slide against other hard metals without liquid lubrication. It is often loosely called a "non-galling stainless steel", but it is actually a nickel-based alloy.
Size Range
- 20–250 mm (typical cast bar)
Grade Specification
| System | Value |
|---|---|
| Grade | Alloy 88 (Waukesha 88 / WM88 equivalent) |
| 🇺🇸 UNS | N26055 |
| Common Trade Names | Alloy 88, Waukesha 88, CY5SnBiM, ILLIUM 8 (equivalent trade references) |
Chemical Composition
| Element | Value |
|---|---|
| Ni | Bal |
| Fe | 5 |
| Cr | 12.5 |
| Mo | 3 |
| Bi | 4 |
| Sn | 4 |
| Mn | 0.8 |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength | ≈ 330–480 MPa (48–70 ksi) |
| Yield Strength | ≈ 260 MPa (38 ksi) |
| Elongation | ≥ 30% (cast condition) |
| Hardness | 121–170 HB (149 HB typical) |
| Elastic Modulus | 186 GPa (27.0 × 10⁶ psi) |
| Galling Performance | Galls at roughly 1/5 the rate of 316 stainless steel (manufacturer data) |
Physical Properties
| Property | Unit | Value |
|---|---|---|
| Density | - | 8.6 g/cm³ (0.31 lb/in³) |
| Coefficient of Thermal Expansion | - | 8.0 × 10⁻⁶ in/in·°F (0–260°C) — similar to 304 stainless steel |
| Thermal Conductivity | - | Low — 16.7 BTU·in/(hr·ft²·°F) at 105°F, valued for temperature-sensitive areas |
| Electrical Resistivity | - | 112.7 µΩ·cm at 77°F |
| Magnetic Permeability | - | ≈ 10⁻⁴ H/m — essentially non-magnetic, not attracted by a magnet |
| Machinability | - | Comparable to 304 stainless steel |
Applications
- Food & Beverage: Rotary lobe & positive displacement pump rotors;Unlubricated bushings, wear rings, pump covers
- Dairy:Pump components for CIP-cleaned process lines
- Pharmaceutical:Hygienic pump and valve internals
- Valves:Valve seats, stems and trim requiring anti-seize behaviour
- Polymer Processing:Low-temperature anti-galling screws and dies
- Defense & Marine:Corrosion-resistant unlubricated bearing surfaces
- General Industry:Any close-tolerance metal-on-metal sliding pair without lubrication