Tuesday, April 11, 2017

Mold marks

Storm drain cover

The triangle with the three screw heads, at the top and and bottom center of the storm drain cover, are mold marks from the casting process.

The center portion of this cover gets buffed regularly by rubber tires; the non-buffed portions oxidize.

Relaxed 3d view of cover

This 3d relaxed view stereogram provides an "in situ" of the storm drain cover.


  1. Are there mold marking in the lower right (and upper left corners) as well?

    1. Yes, a closer look shows that there are some mold marks in those two corners. They are not very distinct, and, are not as interesting as the 'screw head' ones.

      Thanks for catching those!