| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that mold release characteristics upon ejection are bad and, as a result, there is a fear of deteriorating the durability of a mold remarkably by applying an excessive load on the mold or a fear of inviting the cause of trouble in the injection machine, further, forced ejection becomes impossible some times since an injection molded component is hardly deformed when recessed and projected parts are formed on the molded component integrally with the same employing a synthetic resin high in the value of tensile strength and low in the value of elongation whereby the forced ejection of the same is hard. SOLUTION: In the component for a writing instrument, which is manufactured employing the synthetic resin having the tensile strength of 4×102 kg/cm2 or more and the elongation of 200% or less while being provided with a recessed and projected part connected to another component through screwing, the projecting height of undercut of the recessed and projected part is specified so as to be 0.2 mm-0.05 mm. |
