Device for manufacturing austenitic stainless steel drill screws
US5308286A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 16, 1992 |
| Grant date | May 3, 1994 |
| Priority date | — |
| Expiry date | Dec 16, 2012 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16B25/103
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method for manufacturing drill screws from austenitic stainless steel, which offers sufficient hardness for drilling and tapping into sheet iron and avoids the problems of intergranular corrosion and other erosions by taking full advantage of hardenability through cold working of austenitic stainless steel. The drill screw is manufactured by cold working from austenitic stainless steel. The above-mentioned material is formed into the head section (1) and shaft section (2) by header processing. The tip of the shaft section (2) is formed into the drill section (3) with the point (4), and with the cutting edge (5) running up to the tip. This is accomplished by pressing with a pair of pointer dies (7). On the die face (8), the cutting edge (9) and the receiving face (10) face each other. The shaft part (2) is formed into the screw part (6) by threading with a rolling die. Finally, all surface areas are passivated before aging treatment is applied.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.