High quality Butyl tapes

Stain less steel 304 grade Bimetal self drilling Screws available

Decking screws with high drilling capacity available ( used for thicker channel )

A self-tapping screw is a screw which can tap its own hole as it is driven into the material.
Common features are the screw thread covering the whole length of the screw from tip to
head and a pronounced thread hard enough for the intended substrate, often case-
hardened
A Self-Drilling Screw is a Self-Tapping Screw with the added feature of a drill point. The drill
point looks a lot like the point of a drill. It will drill a hole and form the mating threads in one
operation.

Some self-tapping screws are also self-drilling, which means that, in addition to the tap-like
flute in the leading threads, there is also a preliminary drill-like fluted tip that looks much
like the tip of a centre drill. These screws combine a drilling action and the fastener
installation itself into only one driving motion (instead of separate drilling, tapping, and
installing motions); they are thus very efficient in a variety of hard-substrate applications,
from assembly lines to roofing.
There are various types of Self-Drilling screws available suitable for a number of
applications.

Head Styles – Hex Head, Pan head, CSK head, Truss Head, Wafer head etc.

Point Length

The unthreaded section from the point to the first
thread should be long enough to assure the drilling
action is complete before the first thread engages the
drilled metal. Screw threads advance at a rate of up
to ten times faster than the drill flute can remove
metal. All drilling therefore should be complete before
threads begin to form.

DRILL POINT SELECTION

Drill Flute

The length of the drill flute determines the metal
thickness that can be drilled. The flute itself provides
a channel for chip removal during drilling action. If it
becomes completely embedded in material, drill chips
will be trapped in the flute and cutting action will
cease. This will cause the point to burn up or break.

Drilling Through Wood to Metal.

If your application calls for drilling through wood over
1/2" thick, a clearance hole is required. Select a
fastener with breakaway wings for this type of job. The
wings will ream a clearance hole and break-off when
they contact metal surface (minimum metal thickness
0.06") to be drilled.

Thread Selection

*Thread Length.

Always choose a fastener with sufficient threads to fully engage in the base metal. For
attachments to 1/4" base steel, a self-drilling screw should have at least 1/4" of threads.
It is helpful, but not critical, that the threads also engage in the material being fastened.
The head of the fastener provides the bearing force for the material being fastened,
while the threads provide the clamping force in the base material.

*Thread Pitch.

The thickness of material being fastened and diameter of the screw determine the type
of thread pitch to be used. In general, the thinner the fastened materials, the fewer the
number of threads. The thicker the material, the greater the number of threads. This
principle is due to two primary methods of thread engagement/holding power: Clamping
and Threading.

In light gauge metal, the materials are actually being clamped together by the upper and lower threads.

Thinner base material requires a coarser thread pitch to assure proper clamping. The
thicker the material, the finer the threads must be. In very thick metal (3/8" to 1/2" thick),
a fine thread is advisable. This will allow the thread to tap into the base material with less
installation torque than a coarse thread.

Application of butyl tapes in Roofing

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