| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a ceramic screw body provided with a screw part capable of reducing manufacturing cost and having excellent electric insulation property, chemical resistance, protection against corrosion, and strength. <P>SOLUTION: A ceramic bolt 1 being the ceramic screw body is composed of a stem part 10 and a male screw part 11 formed by heating and baking a powder-like raw material containing zirconia being a main component and yttria being a by-component after molding by pressurization to realize such a shape that the male screw part 11 is provided on at least one end side of the stem part 10. Outside diameter of the stem part 10 is smaller than outside diameter of the male screw part 11. A connection part of the stem part 10 and the male screw part 11 has a tapered peripheral side face. A channel part 13 having a curved bottom face is peripherally provided on the peripheral side face on a male screw part 11 side of the connection part. Pitch dimension P of the male screw part 11 is set to be larger than pitch dimension of a coarse thread. A vertex 111 and a trough 112 of a screw thread 110 of the male screw part 11 are machined into curved faces. After heating and baking, surface machining treatment is applied to at least the male screw part 11. <P>COPYRIGHT: (C)2007,JPO&INPIT |
