They want to avoid creating a stress riser at the corner. Any torque on either arm of the L will generate a stress on the corner, and this stress is more concentrated the smaller the radius is. This is not quite as big a concern with a sink cutout because there is far less opportunity to have a torque on one of the sides of a sink cutout (as they are supported on both ends).

I don't think mine is anywhere near 1.5". I will measure it when I get home and report back! I have 4-5 feet that extend on the L.

Thanks Hags!

one limitation is the radius of the CNC tooling assuming the fabricator has a CNC (most do.) this limits an inside radius to 1 or 1.5" depending on the tooling and requires handwork to finish out to a smaller radius.

stress risers can be a real concern but are usually discussed in the context of inside 90 degree corners. for your layout as described it should be a non-issue particularly with quartz.

Dang, shows you how observant I am. Mine is a 1.5"!! It is very generous and looking at it, I would prefer it a little smaller too but not that I ever noticed that until now!!

I can't imagine with the 12" overhang they can't give you a 1". I would imagine there is more risk of fracture in transport and handling then after installation.

Can't see how you could void the warranty if Cambria says 1/2" min.

Thanks Hags. The fabricator now agreed to do a smaller radius, but not sure how small they will go before they abandon responsibility for any damage/cracking. I'll find out tomorrow.

I know this is old, but I've been told that Cambria will go down to 1/4" inside corners, but they do charge extra for this.

I wouldn't go that small in engineered stone. Put a French miter in and have a 90 with no radius if you want tight.

Sophie. What’s wrong with the last design you posted? That looks like a good solution. I have a similar issue.

Sorry kurlanger, but in their infinite wisdom, the mods of this board have banned the greatest asset this board has ever had, Sophie Wheeler. You won't be getting an answer from one of the most knowledgeable persons anywhere here.

I could answer your question, but in remembrance of Sophie, and the horrible way she was treated here, I won't.