Alloy information - Neyoro 28

The perfect alloys for high precision sliding contacts.

Our Neyoro 28 series are soft gold-silver alloys with small amounts of other metals added to produce the varying degrees of hardness needed for specific applications. The Neyoro 28 Series is extremely resistant to tarnish and corrosion, has low resistivity and maintains initial low contact resistance over long periods of service.

Neyoro 28 is resilient enough to serve as a contact spring, so that arm and contact can be made of the same material throughout. This is a real advantage where the contact arm must be small and the contact force is low. The material cannot be hardened by heat treatment, but can be hardened within limits by cold working. Neyoro 28 can be furnished to meet the various tempers of ASTM specifications B4777. In slip ring applications, silver rings, due to surface tarnish or for other reasons, have proved unsatisfactory in many applications where the slip rings must be very small and the energy level of the transmitted signal and the contact force are very low. Ins such cases, Neyoro 28 rings with Neyoro G brushes have proved to be very successful.

Neyoro 28 was developed specifically as a sliding contact material for use in potentiometers wound with relatively soft copper-nickel resistance wires such as constantan, where a soft contact is desirable to avoid excessive wear of the winding. The hardness of Neyoro 28 in the annealed condition provides minimum wear of both winding and contact for single-turn potentiometers. Its low contact resistance and freedom from corrosion are additional factors which make it ideal for this use. In multi-turn potentiometers and in slop rings, the additional hardness of Neyoro 28 is advantageous. It is quite ductile in either the cold-worked or annealed condition. A wire 0.010" in diameter can be flattened to 0.004", or 0.015" in diameter can be flattened to 0.006" thick.

Neyoro 28 is a binary gold-silver alloy that is softer than either Neyoro 28A or B, but in other respects its properties are similar. It was developed as a brush material for use with Neydium 90 silver alloy and coin silver slip rings or commutator segments, where long, trouble-free service is required. Neyoro 28A can usually be substituted if it is desirable to form the spring and contact in one piece. Neither Neyoro 28 nor 28B is generally recommended for springs.

Neyoro 28, 28A and 28B, are available in wire, strip and rolled shapes.