| 摘要 |
PROBLEM TO BE SOLVED: To provide a sewing machine needle having sufficient deformation resistance and wear resistance of a needle tip while keeping high resiliency as a needle. SOLUTION: The needle tip part within the range of 1.5 to 5.0 mm from a needle end 4 on the lower side of a needle hole 2 is defined as a high hardness area of hardness 800 to 950 (HV), the range of 0.1 to 0.5 mm on the upper side following the high hardness area L<SB>1</SB>is defined as a low hardness area L<SB>2</SB>of hardness 500 to 650 (HV), the needle body part of the upper side following the low hardness area L<SB>2</SB>is defined as a middle hardness area L<SB>3</SB>of the hardness 690 to 770 (HV) further, and the high hardness area L<SB>1</SB>on the needle tip side and the middle hardness area L<SB>3</SB>on the side of the needle body part 1 are connected by the narrow low hardness area L<SB>2</SB>. COPYRIGHT: (C)2010,JPO&INPIT
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