Low Profile 10 in. Black Steel Adjustable Support Bracket for Countertops

This info is provided on the site of the bracket..... depends on multiple factors, so you need to read the very clear instructions on their web site!

If you put them pretty close, I believe these would be fine...(if you install them according to directions) ...... 15" over hand is not a big deal....I have over 20", so that is where I would get the solid steel 1/2inch supports...

The do answer this in the product description.....best to read it... I would do more not less, depending on the weight of the counter and the over hang......can't remember what they said off hand....but I think it is about every 2 feet.....get the bigger size then you think....you can go very close to the edge with this very thin steel.

I believe it is 1/4 inch...but the item description clearly states this...(normal ones are 1/2 inch)

this is stated in the product description....OR utube/google the product.....lots of info on spacing out there.....

The brackets have a calibrated preload based upon the weight of the countertop. The table below is used to set the preload based upon 3 of the most common countertop weights: 1 1/4" (3 cm) granite = 18 lbs/sq ft, 3/4" (2 cm) granite) = 12 lbs/sq ft, and lighter materials = 6 lbs/sq ft. The average weight of concrete is about 12 lbs/sq foot. So if the thickness of the concrete is 1" use this value to set the preload. If the concrete is 1 1/2", then use 18 lbs/sq ft to set the preload. Brackets should be spaced about 18" apart.

I don't think you should!!! Don't use the top one!! When you add the REQUIRED "pre load" the bracket it will LEAVE the wall on the top!!!! This won't be possible if you have secured the support via the top hole tight to the wall! I know it is hard to get, but the set screws that you turn on the top of the bracket move the bracket off the wall in order to add the "load" you need to hold up your granite./ counter.

They go under your granite counter tops....they are super thin....and they don't go to the end....about 2 inches from the end of the under neath of the counter...... the bottom part goes INSIDE your cabinets.....so they are really not noticeable when installed. You have to be on the floor looking up to the bottom of the granite to see them!

Hello AmyL, You will still want the added support of the ledger board. The granite shelf is going to be heavy on its own. When you think about the added weight of someone potentially leaning on it that weight gets beyond the shelf brackets ability to balance the load. The ledger board as pictured in your photo can be used instead of an additional bracket on the cabinet side. I hope this helps. Cheers, Chris