You almost certainly know the slotted screw head much better than the flathead screw. Just one extended slit allows for the flat screwdriver to become inserted. Screwheads that demand a countersink will likely have an angular form under the head. Whilst non-countersunk designs will likely be flat. Another prevalent inspection https://typesoflanaiscreen20616.dreamyblogs.com/29747922/types-of-screw-heads-no-further-a-mystery