C.R. LAURENCE P1319C CRL 3/16\” Plastic Screw Anchor Without Shoulder – 100 Each (100 Pack). Year after year, these are our best-selling plastic anchors. CRL Plastic Screw Anchors are designed to be used with wood or sheet metal screws. Their multiple-ribbed construction ensures secure holding power in hard or soft materials, from concrete to plaster. They are available in two styles: the shoulderless anchors will fit flush to the surface, the type with shoulders keep the anchor from slipping through the hole. 3/16\” and 1/4\” (5 and 6 mm) sizes accommodate screw sizes from #4 through #10.. Part Numbers Variations: P1319C Our Best Selling Plastic Anchors | Use in Concrete, Block, Brick and Wallboard | Use With Wood or Sheet Metal Screws | Anchors Without Shoulders