Screw Chucks

[Doris]

Hi everyone,

This will come across as a stupid question but hear me out.

I have 2 screw chucks and they both seem to have different diameter screws, which is fine. But lately i have found that one hole will fit for soft wood and not for hardwoods.

Am I doing something wrong here? I thought that one size would fit all but I've noticed that this doesn't seem to be the case.

 

[Random Orbital Bob]

It's just because the threads sink further into (the more spongy) softwood than they do hard so your hole diameter needs to be less for sw compared to hw for the same screw diameter.