Screws for MDF

[legul]

What dimension should you actually use when screwing together MDF boards? I understand that you have to pre-drill in the board that will be fastened and also pre-drill in the "lower board on edge" (it's supposed to become a wardrobe). I have 16 mm boards and was recommended a 4.5 X 30 "ESSVE Cutter Wood screw" but I think it's too short and I don't feel that the screw "grips" properly, how should you get the boards to hold together properly? What dimension should you pre-drill with, if I measure my screw 4.5 X 30 then the core is 2.9. Does that mean I should use 3 mm for a 4.5 mm screw?

 

[AndersS]

Glue, regular wood glue. You get a much more stable construction, which I also apply to certain IKEA furniture. Not detachable but better stability as I mentioned earlier.

 

[xibeca]

Spax has a special MDF screw, Spax-M (http://www.spax.com/gb/pdf/2/9.pdf), which works excellently when assembling MDF. Just a little glue and then tighten, no pre-drilling. However, I do not know where you can find it outside of Stockholm. Good luck!

 

[AndersS]

If you use glue, the purpose of the screw is to hold the material together while the glue cures. It is the glue that should hold the construction together.

 

[legul]

Apparently, it is not very common for people to build with MDF, so I guess I will have to explain how I solved my screwing.

Screw: 4.5X50
Drill 2 mm
No glue so I can dismantle the furniture without ruining it.

 

[imported_Byggaren]

There is a very good screw for MDF when screwing into the edge of a 16 mm board. It is sold, among others, by Clas Ohlson and is called Coupling Screw with item numbers: 11-1336-50 for 50 mm length and 11-1336-70 for 70 mm length. However, 50 mm length is quite sufficient. 15:-/10 pcs. or 129:-/100 pcs.

The entire 'block' is assembled with such screws. (Not the lady in the picture of course )




_____________________
Byggaren

 

[legul]

Thank you Builder
Impressive construction.
Unfortunately, I can't read your entire post, the text is cut off on the right, but I went and looked at Classe and saw the screw, what did you pre-drill with?

 

[imported_Byggaren]

Thanks Byggarn
Impressive build.
Unfortunately, I can't read your entire post, the text cuts off to the right, but I checked Classe and saw the screw, what did you pre-drill with?

I'll try again after the phone/Internet went out just when I had finished writing the response to you and was about to send it almost two weeks ago. However, I managed to adjust my post so that the text could be read.

The screw's core is 4 mm. Therefore, I first drilled (on the edge of a 16 mm MDF board) with a 4.2 mm bit, but it didn't work, it split. Then I increased to 4.5 - 4.7 and ended at 5 mm (outer thread's diameter is 7 mm). Usually, it works well, provided you drill in the middle of the edge and perpendicular (I used a drill guide from Classe, item number 20-4826 at 139, but if it was uncooperative, it resulted in a small bulge on the flat side in the direction the bit had drifted.

The actual 'shaft' of the screw requires a 7 mm bit and the holes must also be countersunk for the 'flange.'
___________________
Byggaren

 

[Saxpy]

Spax has a special MDF screw, Spax-M ([link]), which works excellently when assembling MDF. Just a little glue and then join together, no pre-drilling. However, I don't know where you can find it outside Stockholm. Good luck!

Reviving an old thread... Where in Stockholm can you get this screw? Axminster has it but it gets a bit expensive if you're not ordering more from there...

 

[xibeca]

Available at Fredells.