Stud Bolts, Nuts, Screws, Threaded Rod & Washers
Electroless Nickel Plating Fasteners are coated by a chemical process that deposits an even layer of nickel-phosphorus or nickel-boron alloy on the surface of a solid substrate, like metal or plastic. The process involves dipping the substrate in a water solution containing nickel salt and a suitable reducing agent.
Unlike electroplating, the process does not require passing an electric current through the bath and the substrate; the reduction of the nickel cations in solution to metallic nickel is achieved by purely chemical means. Thus EN plating creates an even layer of metal regardless of the geometry of the surface in contrast to electroplating which suffers from uneven current density due to the effect of substrate shape on the electric field at its surface.
Electroless Nickel-PTFE is a nickel-phosphorous-polytetrafluoroethylene (PTFE) co-deposit on metal substrates. The process yields a surface with the engineering properties of nickel and the additional lubricity of PTFE.
| Properties | Electroless Ni-P | Hard chromium |
|---|---|---|
| Melting point (°C) | 890 | 1610 |
| Internal stress on steel (MPa) | < 7 | 200-300 |
| Electrical resistivity (|iWm) | 0.9 | 0.14-0.66 |
| Thermal conductivity (W/mK) | 8 | 67 |
| Modulus of elasticity (GPa) | 200 | 100-200 |
| Elongation (%) | 1-1.5 | <<0.1 |
| Coefficient of thermal expansion (10 - 6 /°C) | 12 | 6 |
| Adhesion strength (MPa) | 300-400 | Good |
| Tensile strength (MPa) | > 700 | < 200 |
| Hardness (HV 0.1 ) | 480-500* | 800-1000 |
| Coefficient of friction versus steel (lubricated) | 0.13 | 0.16 |
| Taber wear resistance (mg/1000 cycles) | 15-20 + | 2-3 |