Nails having selected heat treatment and hardening
AssigneeIllinois Tool Works Inc.
InventorsGeronimo E. Lat, Louis M. Spoto, Kent B. Godsted
Life of this patent
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Abstract
A selectively hardened nail includes a nail head, an elongated shank, and a tip. A portion of the nail shank is made harder than the remainder by selectively heat treating that portion, and cooling it. The nail has controlled bending properties. The selectively hardened portion does not significantly bend when the nail is fired at a surface using a power driving tool, or during use of the nailed object.
Claims20
A selectively hardened nail, comprising a nail head, an elongated shank, and a tip, the nail including:
- a selectively hardened portion, encompassing an axial part of the shank, which has a Rockwell "C" hardness of at least about 40;
- and
- a softer portion, encompassing another axial part of the shank, which has a Rockwell "C" hardness of not more than about 35;
- wherein the selectively hardened portion encompasses an upper part of the nail shank below the head.
A selectively hardened nail, comprising a nail head, an elongated shank, and a tip, the nail including:
- a selectively hardened portion, encompassing an axial part of the shank, which has a martensitic metallurgical structure;
- and
- a softer portion, encompassing another axial part of the shank, which has a ferritic pearlitic metallurgical structure.
A selectively hardened nail, comprising a nail head, an elongated shank, and a tip;
- the nail including:
- a selectively hardened portion, encompassing an axial part of the shank, which has been selectively heated to at least about 1400.degree. F. and quenched;
- and
- a softer portion, encompassing another axial part of the shank.
A selectively hardened nail, comprising a nail head, an elongated shank, and a tip, the nail including:
- a selectively hardened portion, encompassing an axial part of the shank, which has a Rockwell "C" hardness of at least about 40;
- and
- a softer portion, encompassing another axial part of the shank, which has a Rockwell "C" hardness of not more than about 35;
- wherein the selectively hardened portion encompasses an intermediate part of the nail shank.
Dependencies are inferred from the claim text.