| Year | 1951 |
| Date | 01-Nov |
| Volume | 105 |
| Issue | 2,632 |
| Page | 583 |
| Category | In The Workshop |
| Part | 101 |
| Title | Making a Twist Drill Grinding Jig |
| Author | "Duplex" |
| Notes | Showing the point angle of a standard twist drill, clearance angles or back-off, cone angles, the early type of drill jig described (Van Royen), lip gauge, principles of construction |