AMPCO® Manganese Bronze

AMPCO® 674

Nominal composition:

Aluminum(Al)1.6%Extruded and Dawn


AMPCO® 673 and AMPCO® 674 are wrought zinc-manganese-silicon-lead-copper alloys which are widely specified for a variety of bearing and/or corrosive applications: bushings, gears, cams, nuts and bolts, connector rods, idler shafts and other shafting, worm gears, feed fingers, lead nut screws, etc.

Both alloys have excellent capacity for hot forming, with hot forgeability ratings of 100. AMPCO® 674 exhibits a machinability rating of 25%, while AMPCO® 673 has a considerably higher rating of 80%.

The most significant difference in the two materials is in the higher lead content of AMPCO® 673 which increases that alloy’s machinability but decreases its tensile and yield values.

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