| Horological hints & tips | May 2006 |
Letting down mainspringsLet-down keys are quite expensive. You also need several to cover a range.Why not use a good old-fashioned chuck tap wrench? These are fully variable and will fit any size of square shank, and are well strong enough to tap 6mm to 8mm threads through steel plate. William Maysey, UK |
| Current issue | Sample copy | Subscriptions | Hints & tips |
|
| © 1977 to 2008 Splat Publishing Ltd |
![]() |