Low expansion cast iron lapping tool
AssigneeKabushiki Kaisha Toshiba
InventorsTakanobu Nishimura, Motoo Suzuki, Tastuyoshi Aisaka
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Abstract
A lapping tool with a flatness in the range below 20 .mu.m which is made of at least cast iron having an austenitic matrix and consisting essentially of from 1% up to 3.5% carbon, up to 1.5% silicon, from 32% to 39.5% nickel, from 1% to less than 4% cobalt, up to 41% of the combined total of nickel plus cobalt and the balance substantially all iron providing a low expansion coefficient, good castability, good cutting properties and good damping capacity. (By % is meant % by weight).
Claims9
A lapping tool with a surface roughness in a range below 20 .mu.m which is made of at least a cast iron having an austenitic matrix and consisting essentially of from 1 to 3.5% carbon, up to 1.5% silicon, 32 to 39.5% nickel, 1 to less than 4% cobalt, up to 41% of the combined total of nickel plus cobalt and the balance substantially all iron. (% is meant for % by weight).
Dependencies are inferred from the claim text.