| Year | 1952 |
| Date | 25-Sep |
| Volume | 107 |
| Issue | 2,679 |
| Page | 418 |
| Category | Drilling |
| Part | |
| Title | A Twist Drill Point Grinding Jig |
| Author | W.D.Arnot |
| Notes | Chuck arbor, the base, bolts, trial assembly, ball retainers, the cam, locking-collar, operating wheel, camm counter-thrust pillar, return spring, withdrawal spring, feed-limiting screw, setting the drill for grinding, operation, setting the jig |