Screws having selected heat treatment and hardening
US6109851A · kind A · utility
33Cited by
45References
25Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 13, 1999 |
| Grant date | Aug 29, 2000 |
| Priority date | — |
| Expiry date | Jan 13, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2221/01
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A carbon steel screw has one or more portions which have been selectively hardened by selective heat treatment and quenching. In one embodiment, an upper portion of the screw head is selectively hardened to prevent or reduce damage when torque is applied using a driving tool. In another embodiment, the screw tip is selectively hardened for more effective penetration into a substrate. Preferably, the selectively heated portions are selectively quenched to reduce or avoid distortion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.