PURPOSE: To provide a concrete nail that has two stepped screw portions, and is difficult to draw out after being fixed in concrete, and is finely cut by the radial notch in the neighborhood of the hole, and has larger stability than that of conventional nails when inserted into a hole.
CONSTITUTION: This screw nail comprises a first screw portion 28 having a uniform pitch and extending from a penetrating tip 16 toward a tightening head 14 along a shank 12; and a second screw portion 32 formed on the shank 12 at almost middle of the threads of the first screw portion 28. The second screw portion 32 has a smaller diameter than that of the first screw portion 28, and forms a first portion 24 while being screwed into the concrete hole 34. The first screw portion 28 elongates from the end of the second screw portion 32 toward the tightening head 14, and forms a second portion 26 for holding powder produced while being screwed into the concrete.
| WO/2009/087245 | UNIVERSAL ELASTIC RIVET |
| JPH09142335 | FASTENING STRUCTURE FOR ALUMINUM ALLOY SHEET AND STEEL SHEET OF VEHICLE FRAME |
RARUFU DEII TENIYUUTA
MAACHIN JIEI NIRUSEN
