Wood screw

[Alfredo]

I don't think I need to pre-drill since I don't need to screw so close to the edges.

The advice to pre-drill likely wasn't about the risk of cracking near edges but rather to ensure the threads don't grip the "loose" part and only grip the "fixed" part. If you have a "too short" screw, the threads will catch on both parts. By pre-drilling the "loose" part, you avoid this.

At least that's how I understood the advice to pre-drill.

 

[Eddi Thomason]

The advice about pre-drilling was probably not about the risk of cracking near edges but rather about avoiding the threads gripping the "loose" part instead of just the "fixed" one. If you have a "too short" screw, the threads will engage both parts. By pre-drilling in the "loose" part, you avoid that.

At least that's how I interpreted the advice about pre-drilling.

I usually use clamps to avoid that problem!

 

[JOW]

Alfredo: that's what I meant... but you wrote it awfully much shorter

Nik206, yes, if there's space, it's not always possible.

 

[Alfredo]

Alfredo: that's what I meant... but you wrote it awfully much shorter .

I'm lazy.

yes, space permitting, not always possible.

And if there's a lot to screw, it's quite cumbersome, if it even works. Faster to pre-drill.

 

[Mikael_L]

But I actually meant to pre-drill to reduce the risk of splitting.

I think there's a considerable difference in the risk of splitting when I go from a 5 to 6 mm screw.
Especially with those with a countersunk head.

OK, a couple of decimeters from the end grain it never splits, but then if you get closer...

 

[Alfredo]

But I actually meant to pre-drill to reduce the risk of it cracking.

Missed your post about the risk of cracking. :blushing: And yes, of course, I agree that many times it's good/necessary to pre-drill to reduce the risk of cracking!

 

[Anders_Nilsson]

But I actually meant pre-drilling to reduce the risk of it cracking.

I think there is a significant difference in the risk of cracking when I go from a 5 to a 6 mm screw. Especially with those with a countersunk head.

OK, a couple of decimeters from the end grain it never cracks, but then as you get closer...

Yep, you should pre-drill with the screw's core diameter, it's the threads that provide the strength and they cut better when it's pre-drilled correctly. It's also not wrong, as someone mentioned, to pre-drill even the part to be fastened "a little tight." Check the box for how to drill. Otherwise, you can measure the core diameter. Or roughly say that you drill with about half the dimension.

/Anders

 

[thomasx]

Since I started using screws that actually cut the wood fibers, I've had very few problems with cracking wood, basically only caused by the head itself near the end. Highly recommended.

 

[Dr Fozz]

Since I started using screws that actually cut the wood fibers, I've had very few problems with the wood cracking, basically only caused by the head itself near the end. Highly recommended.

Tips on a good screw brand?

 

[thomasx]

Any tips on a good screw brand?

Heco and Fischer can be found in many places.

 

[J.B.]

Essve Cutters are great, available for both indoor and outdoor mounting, and it is C4 classified. I have used it in the horse stalls down there where it is urine and humid, and I can't see any corrosion after 4 years; a regular electro-galvanized one would have been gone by now.

 

[vojma]

Regarding pre-drilling to prevent the thread from catching in "the loose part."

If I'm going to insert a 6x100, I usually pre-drill with about a 3mm drill through the entire board and then with a 5.5mm from the back as far in as the threads will go. That way, you get a good base for the head to pull in. If you drill with 5.5 through the entire board, the head tends to sink in too easily.