Title:
SCREW
Document Type and Number:
Japanese Patent JP2020106072
Kind Code:
A
Abstract:
To provide a screw in which screwing-in can be performed by a general-purpose driver bit and which is capable of suppressing occurrence of head crack by preventing an excessive fastening force from acting on the screw at a time point in which fastening is completed.SOLUTION: In a screw 11 which comprises a head 14 in one end of a screw shaft part 13 and in which a square recess 21 to which a square tip end of a driver bit is fitted is provided in the head 14, a recessed groove 22 is provided from a top face 14a of the head 14 to a bottom of the square recess 21 at a position closer to a rear part of an inner surface 21b of each of sides 21a of the square recess 21 in a screw-in rotation direction on the inner surface 21b. A narrow inner surface 23 is formed between an opening edge which is positioned at a rear side of the recessed groove 22 in the screw-in rotation direction, and a rear end of the inner surface 21b in the screw-in rotation direction.SELECTED DRAWING: Figure 3
Inventors:
VOO DON HAI
Application Number:
JP2018244097A
Publication Date:
July 09, 2020
Filing Date:
December 27, 2018
Export Citation:
Assignee:
WAKAI HOLDINGS CO LTD
International Classes:
F16B23/00; F16B25/10
Domestic Patent References:
JP2011075078A | 2011-04-14 | |||
JP2012159092A | 2012-08-23 | |||
JPH09264312A | 1997-10-07 | |||
JP2007321851A | 2007-12-13 |
Foreign References:
EP1538348A1 | 2005-06-08 | |||
US6293745B1 | 2001-09-25 |