Most material splitting is prevented because of the Trim Head Screws' exceptionally small head and the W-Cut thread design. Pre-drilling is only necessary if the building material's limitations require a pilot hole to be drilled, as in hard woods like Mahogany, Ipé, etc.
We have modified its innovative FIN/Trim Head Screw to include reverse threading under the head of the fastener. Based on extensive tests, we have found that the reverse thread helps the screw head disappear beneath the surface of the wood composite material reducing or eliminating the dimple that sometimes appears when using the FIN/Trim screw. The reverse thread feature is available on RT/Composite Head screws from 2" to 3 1/8".