I was wondering what the two grey tile like bricks in the image below are? I wish to order some online, so would appreciate knowing their name.
This is a 3743 - Technic, Gear Rack 1 x 4 and there are 2 times 2 of these in your picture (2 on the left and 2 on the right).
I guess your description is a little vague, because if you are talking about the middle part (the shining light gray pieces), they are actually not bricks/tiles, but the axle end of an NXT motor (the right side of the motor in the below picture).
Technic, Liftarm 1 x 3 Thick
Item No: 32523
They are/were produced in many colours including both 'light bluish grey' and light grey'.
More details on bricklink
Just realised you you referred to them as 'tile like bricks' so maybe it is this:
Part 3743 Technic, Gear Rack 1 x 4 Bricklink link
It would be a lot easier if you could isolate the elements you are interested in and take better photo