Self drilling screws eliminate the need for separate drilling and tapping tasks for faster, more economical installations of materials such as aluminum and sheet metal. There is no need for a pilot hole saving you time and money; Drilit® Self drilling screws are manufactured to have a drill bit head that creates a hole while fastening material for faster installations of your projects.

General Uses and Applications for Drilit Self-Drilling Screws

Steel-to-steel connections
Wood-to-steel connections
Composite material-to-steel connections

Applications and Benifits of Drilit Self-Drilling Screws

Eliminates separate drilling and tapping operations
Fasteners coated with Stalgard® and Gray Stalgard® finish typically show no red rust or other base metal corrosion on significant surfaces after 1000 hours of 5% neutral salt spray exposure (per ASTM b117)
Screws with EPDM bonded Sealing washers are available in multiple sizes and configurations for applications requiring a weather-tight seal
Fasteners coated with Gray Stalgard® are compatible with ACQ-treated lumber with retention levels no higher than .25 pcf

Approvals and Listings of Drilit Self-Drilling Screws

International Code Council, Evaluation Service (ICC-ES), ESR-3294
International Code Council, Evaluation Service (ICC-ES), ESR-4367
Code compliant with the International building Code/International Residential Code: 2021 IbC/IRC, 2018 IbC/IRC, 2015 IbC/IRC, and 2012 IbC/IRC
Tested in accordance with ICC-ES AC118 for use in Steel-to-Steel Connections
Tested in accordance with ICC-ES AC500 for attaching Miscellaneous building Materials to Steel

Drillit Self-drilling Screws Save You Time And Money

Dillit® Extended Capacity Self-Drilling Screws

Drilit Self-Drilling Screws with Bonded Sealing Washers

Drilit Wood to Metal Self-Drilling Screws

Drillit Self drilling Screws Out Preforms other Screws

Drillit Self-drilling Screws are Durable

Drillit Self-drilling Screws are Reliable

Self Drilling Screw Design Diagram and Technical Specifications

Usable Thread Length = UTL
length minus flute length & first 3 (lead) threads

Drillit Self-drilling Screws Usable Thread Length

Application Thickness of Elco Drilit® Self-Drilling Screws

Coarse thread better for thin material (<16 gauge or .060”)

Fine thread better for thicker material (> 16 ga.)

Self-Drilling Screw Drill Point Sizes

#1 Self-Drilling Screws – Smaller than Thread Minor
#2 Self-Drilling Screws – Equal to Thread Minor
#3 Self-Drilling Screws – Mid-range between Major & Minor
#4, 4.5 & 5 Self-Drilling Screws – Sized slightly larger than mid-point

Drill Point must be finished drilling through the entire application before the threads engage in the top of the material.

Drilling and Tapping Capacity (Maximum Material Thickness)*

* NOTE: Some drill and tap capacities may vary due to special features on some fasteners. Refer to ordering and technical information for difference in drilling and tapping capacities for any individual fastener

† Lapped panels: 18 ga. to 18 ga.

Drilling Capacity/ Application Thickness

The drilling capacity indicates the maximum diameter a self-drilling screw can produce in the material thickness by point type.

Maximum Combined Material Thickness By Point Type Selectiom

** Applies to #12 diameter screws with point types 4, 4.5 and 5

Drilit® Self-Drilling Head Types

Thread Thickness

A Self-Tapping Screw That Drills its Own Hole!

Standard Self Drilling Screws -Hardness
Case Hardened product has high hardness, low ductility

Case Hardening –The Standard Heat Treatment Process for Carbon Steel and 410 Series Stainless Self-Drilling Screw products are made for non-structural and non-dissimilar metal or light duty thin steel applications.

Case Hardening

Outer “Case” =
High hardness is required to drill steel
Core (inner section)
Carbon steel: Hardness from RC 32 to 40 (IFI)

Stalgard®High-Performance Protective Coatings
Provide consistent, high corrosion resistance in construction applications

1000 hour Salt Spray
ASTM B117 Salt Spray Testing Compliant

ICC Approved Elco Drilit® Self Drilling Screws