| Year | 2015 |
| Date | 24-Jul |
| Volume | 215 |
| Issue | 4,513 |
| Page | 184 |
| Category | Workshop |
| Part | |
| Title | Further developments in drill sharpening |
| Author | D.A.G.Brown |
| Notes | Looks at four facet geometry. Proof of the pudding, practical demonstration, other models of cutter grinder |