Wanted to make a tapered table saw clamp with cam lock clamps. The base of the 1/2" cam lock did not fit in the slot. Measured with vernier calipers and found the 1/2" groove diameter is 0.47 and the 3/8" groove diameter is 0.34. Couldn't measure 5/16" as it's a single cutting blade. This can be acceptable when hanging items on slots; however, did not work with cam-lock clamps.