Fixing body top and sides together

[richard37066]

I may open up a can of worms here but I've never claimed to be anything but an opinionated, incorrigible old codger - so here goes.

A typical wood screw has threads which not only taper in diameter but also in depth as well as one moves towards the tip of the screw. It's been my experience that, when one attempts to really crank down on a wood screw, there's always the chance of easily stripping the hole. A sheet metal screw, on the other hand, has threads which are consistent in diameter and depth except for the first couple of teeth at the tip. It is my (un)considered opinion that the sheet metal screw therefore affords greater holding strength given the fact that the shear strength of the wood is the limiting factor regardless of the type of screw used. In other words, the greater the "bite", the greater the ultimate strength of the joint.

Yes, I know - wood screws have been used for millenia and proven reliable in most applications. I, on the other hand, prefer to crank things down with a torque wrench whenever possible. I build things like the Brooklyn Bridge - it'll never fall apart.

With ALL due respect,

Richard

[sheffield steel]

Spot on Richard, I use St/St self tappers.
Dave .

[sheffield steel]

Spot on Richard my friend, I use St/St self tappers.
Dave.

[bluesteel]

Well, glue and screw is certainly the way I'm going with mine. And the point about self-tappers is really on the money! Got the workshop back in order now after the winter, and the sawbench is good to go, so no more excuses, time to cut those pieces of timber and start putting the body together. Cross fingers!

Will

[johan]

I would leave open the screw holes it gives you the opportunity to check the screws on their resistance because the wood works and maybe shrinks. johan.