I need to attach a 120 x 200 cm (47.2" x 78.7") whiteboard to a concrete wall with some plaster on it, and the whiteboard arrived with 4 screws which seem kind of small to me.
I will be attaching the whiteboard in all four corners with these screws, but compared to the size of the whiteboard I find them to be rather small. The whiteboard is 15 kilograms (33 pounds) heavy.
I would like to use the install kit that came with the whiteboard, since I don't have longer screws of the same diameter to fit the wholes in the corners of the whiteboard (and would like to avoid an unnecessary trip to a hardware store to buy some, given the current pandemic) but I'm worried the whole thing will just come apart and fall if I use the provided kit.
So my question is, are these screws appropriate for mounting the whiteboard? Or should I use longer ones? What length would be appropriate?