Steel Torx Drive Flat Head Double Lock Screw for exterior use - Double ThreadLok™ design pulls
and holds boards tight, preventing screws from backing out as
lumber dries out. Ribbing on the seat of the screw head allows
countersinks the screw without mushrooming. Torx plus drive means
better grip with power drivers and less stripped screws. Suitable
for marine and industrial applications where corrosion resistance
While stainless steel offers the
ultimate surface protection, it does not have the shear strength
of a the comparable carbon steel HCR-X series. I would not
recommend stainless steel for structural applications. They are
great for decks, rails and sheathing.....especially exposed
fasteners as the aeshetics are better.
These screws are sold in
MasterPacks....three 5 lbs boxes.
Comparison Photo -
standard vs doublelock stainless screw