Using most masonry fasteners can be such a hassle. First you drill a clearance hole in the lumber, then a hole in the masonry for the anchor sleeve, (meanwhile making sure everything is still lined up). Finally, everything comes back apart so you can drop the anchor sleeve in the hole. Hopefully, the sleeve will grab when the screw is tightened.These great new concrete screws don't use any type of anchor sleeve at all. In fact, all you do is drill a hole into the concrete through the part you are anchoring and drive the screw. Because of the special thread pattern and extra hard steel, the screw cuts its own threads in the concrete. These screws aren't just painted for looks. Their color comes from a special epoxy coating, so they pass a 25 cycle Kesternich corrosion test with less than 15% red rust! Give them a try - they are perfect for attaching framing lumber, electrical boxes, brackets, or almost anything else to concrete. Not recommended for use in brick or cinder block. This item requires a non-standard 5/32" diameter pilot hole.
CONCRETE SCREW ENGINEERING DATAPittsburgh Testing Laboratory tested the 1/4" concrete screws for both pull-out and shear in two grades of structural concrete using 2-3/4" long screws embedded to a depth of 1" in a 3/16" drilled hole. Tests for pull-out and shear were repeated three times for both concrete grades. Test values for other materials will be different.
Test: Pull-out Load (lb) Shear Load (lb) Concrete Strength: 3,000 psi 4,000 psi 3,000 psi 4,000 psi Test 1 1,445 1,690 1,610 1,420 Test 2 1,510 1,645 1,545 1,585 Test 3 1,490 1,665 1,550 1,525
Independent testing of the 3/16" masonry screws was performed in a similar manner in 3,725 psi hard rock concrete. The pull-out values shown below are the average for ten tests:
Embedment: 1" 1-1/4" 1-1/2" 1-3/4" Pull-out Load (lb): 1,030 1,315 1,450 1,834
- Additional Information
PRODUCT GROUP SCREWS & FASTENERS CATEGORY Concrete Screws SUB-CATEGORY Concrete Screws THREAD SIZE 3/16" LENGTH 1-3/4" MATERIAL Epoxy RECESS Combo HEAD Flat BRAND NAME McFeely's THREAD TYPE Tapping POINT TYPE Concrete DRIVER BIT TYPE #2 QUANTITY 25-Pack COLOR N/A SHIPPING RESTRICTIONS N/A SKU RFR-0316-D