this sort of screw is often a non-structural fastener. It is supposed to become tightened and loosened by hand using the ridged sides. Some are designed with a key-like flat facet or fashioned for flat or Phillip head https://types.blog/types-of-screw-heads/
The Ultimate Guide To types of screw heads
Internet 2 hours 36 minutes ago mattiesgtw431727Web Directory Categories
Web Directory Search
New Site Listings