Elgiloy

Elgiloy®, a cobalt-chromium-nickel spring alloy

Elgiloy® (UNS R30003, W.Nr 2.4711), sold in Europe as Phynox, is a cobalt-chromium-nickel-molybdenum alloy in which cobalt is the largest constituent and iron makes up the balance. That puts it in a different class from the nickel-chromium heat-resisting grades: it is specified for fatigue strength, corrosion resistance and non-magnetic behaviour, not for oxidation resistance at furnace temperatures. It is cold worked and then age hardened, and reaches its highest strength in thin sections — which is why it is most often ordered as strip, foil and wire.

Key Properties:

• Very high fatigue strength when cold worked and age hardened
• Corrosion resistance in chlorides, seawater and sour (H₂S) service
• Non-magnetic
• Good resistance to stress relaxation, so a spring holds its load
• Biocompatible — ASTM F1058 is a surgical implant specification

Applications:

• Springs, diaphragms and pressure-sensing elements
• Medical devices — stents, catheters, orthodontic and surgical instruments
• Oil and gas — sour-service springs, subsea valve and choke internals
• Aerospace — clock and power springs

Available Forms:

• Elgiloy Sheets
• Elgiloy Plates
• Elgiloy Foils
• Elgiloy Coils
• Elgiloy Strips
• Elgiloy Rods
• Elgiloy Round Bars
• Elgiloy Hex Bars
• Elgiloy Wires
• Elgiloy Wire Mesh
• Elgiloy Pipes & Tubes