To clinch a nail is to secure the nail by bending it down after it has protruded through the piece of wood to the other side. Bolts can also be in a clinch. When you hammered down nails as a boy, building your tree house, you didn’t know it but you clinched all those nails.
Reasons to Clinch a Nail
The reason to clinch a nail is that it significantly prevents nail withdrawal. You should always clinch a nail across the grain, for better nail withdrawal resistance.
In green wood especially, a clinched nail will give from 50 percent to 150 percent or more resistance to withdrawal than a nail that isn’t clinched.
When green wood seasons and tightens, then the resistance between a nail that has been clinched and one that hasn’t goes up over 300 percent.
Because of the unsightly nature of clinching nails, it is generally confined to those areas out of sight or in construction of boxes or other temporary containers.