Pittsburgh Testing Laboratory tested the 1/4” 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 (Lbs)			Shear Load (Lbs)
Concrete Strength:	3000 PSI	4000 PSI	3000 PSI	4000 PSI
	1445	1690	1610	1420
	1510	1645	1545	1585
	1490	1665	1550	1525

Independent testing of the 3/16” masonry screws was performed in a similar manner in 3725 PSIHard Rock concrete. The pull-out values shown below are the average for 10 tests.

Embedment:	1”	1-1/4”	1-1/2”	1-3/4”
Pull-out Load (Lbs)	1030	1315	1450	1834

Eliminate anchor sleeves with these concrete screws. Just drill a hole into the concrete through the part you are anchoring, then drive the self-tapping screw. Fasteners should be embedded between 1" and 1-3/4" into the concrete, with pilot holes at least 1/4" deeper than the expected screw penetration. In extra hard concrete, a 7/32" pilot may prevent breakage and make the 1/4" screws easier to drive. In addition to epoxy coated steel, these screws are also available in 410 Stainless steel. Unlike most stainless grades, the 410 series is hardenable, making it perfect for these masonry fasteners, although some corrosion resistance is sacrificed. It isn't unusual for the 410 stainless screws to have a very light red tint after exterior exposure. Note: These screws are not designed for use in brick or cinder block (concrete block is OK). Made in USA/Canada or Taiwan.