Edges of mounting holes or mounting threads should be kept .150 away from plate edges. Allow ample distance between features Allow at least .060 land area between grooves and features, and at least .045 between round holes and grooves and other features. The more the better. Put radii on groove paths Designing grooves with generous radii allows for shorter CNC tool paths and provides better laminar fluid flow characteristics. Putting round grooves in plates requires flipping the plate for machining which is more expensive to manufacture and can create tolerance and misalignment problems.
Square grooves are better but the sharp corners can create stress points.
Square grooves with radius corners are better yet but may require special tooling or double machine paths which can be more expensive to manufacture. See the chart below for Rothermel Associates' standard groove dimensions. Multiply valve by desired volume to get proper groove length. The table above shows our standard groove dimensions. The grooves are machined by using a ball-end mill.