Washer Head, Stainless Steel Self-Tapping Wood Screw
  • Code Approval
  • ICC, ETA
  • Connection Type
  • Wood/Wood
  • Applications
  • Timber Framing, Log Home Building,
    Mass & Heavy Timber Construction

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Washer Head

Ring Thread Tip

Corrosion Resistant


Product Description

Product Description

The ASSY A2 Stainless Steel wood screw is structural, corrosion-resistant, and self-tapping with a large washer head that eliminates the need for an additional washer. The screw design also reduces wood splitting while offering a precise setting without the need for pre-drilling.  Code-approved reliability, the ASSY A2 SK has been awarded an ICC-ESR approval in the United States.


Diameters1/4″ (6 mm)5/16″ (8 mm)
Lengths3-1/8” (80 mm)  to  14-1/4” (360 mm)
  • Corrosion-free
  • Each increase in screw diameter also increases the screw’s washer head diameter
  • Ring thread tip reduces wood splitting and promotes precise setting
  • Provides tremendous head pull-through capacity
  • Partially threaded to pull members together tightly
  • Suitable for ledger board to rim joist connections, and ledger board to stud wall connections
  • No additional washer required

The ASSY A2 SK is suitable for a broad range of projects from log home building to multi-story mass timber construction. 



SpecificationASSY A2 SKThread LengthAW Drive BitPackaging Qty.
# ItemMaterialHead
A2SK0680Stainless SteelWasher Head1/4" x 3-1/8"6 x 802"50AW 30100
A2SK0690Stainless SteelWasher Head1/4" x 3-1/2"6 x 902"50AW 30100
A2SK06100Stainless SteelWasher Head1/4" x 4"6 x 1002 3/8"60AW 30100
A2SK06120Stainless SteelWasher Head1/4" x 4-3/4"6 x 1202 3/4"70AW 30100
A2SK06140Stainless SteelWasher Head1/4" x 5-1/2"6 x 1402 3/4"70AW 30100
A2SK0880Stainless SteelWasher Head5/16" x 3-1/8"8 x 802"50AW 4050
A2SK08100Stainless SteelWasher Head5/16" x 4"8 x 1002"50AW 4050
A2SK08120Stainless SteelWasher Head5/16" x 4-3/4"8 x 1203 1/8"80AW 4050
A2SK08140Stainless SteelWasher Head5/16" x 5-1/2"8 x 1403 1/8"80AW 4050
A2SK08160Stainless SteelWasher Head5/16" x 6-1/4"8 x 1603 1/8"80AW 4050
A2SK08180Stainless SteelWasher Head5/16" x 7-1/8"8 x 1803 1/8"80AW 4050
A2SK08200Stainless SteelWasher Head5/16" x 7-7/8"8 x 2003 1/8"80AW 4050
A2SK08220Stainless SteelWasher Head5/16" x 8-5/8"8 x 2203 1/8"80AW 4050
A2SK08260Stainless SteelWasher Head5/16" x 10-1/4"8 x 2604"100AW 4050
A2SK08300Stainless SteelWasher Head5/16" x 11-7/8"8 x 3004"100AW 4050
A2SK08360Stainless SteelWasher Head5/16" x 14-1/4"8 x 3604"100AW 4050
CAD Drawings

CAD Drawings

ProductASSY A2 SK DiameterFile Extension
ASSY A2 SK1/4"6
ASSY A2 SK5/16"8
Design Guides

Design Guides

Structural Screw Design Guide

The most complete tool for high-capacity mass timber connections design using ICC and CCMC code approved ASSY structural fasteners.

Structural Mass Timber Fastening Design Guide

Companion to the Structural Screws Design Guide, it provides pre-designed, easy-to-read tables for tens of mass timber connections using high-capacity ASSY self-tapping screws.

Code Approvals

Code Approvals

ICC Code Approval ESR-3179 for Partially Threaded Fasteners - 2021 Edition (August)

ISO 50001 Certification for ASSY Fasteners

LA Research Report (LARR): RR 26073

Installation Instructions

Installation Instructions

Structural Fasteners Installation Guide

The structural fasteners installation guide is a practical document designed to simplify the installation process of ASSY self-tapping screws.

White Papers

White Papers

Timber Moisture Content Changes and Associated Stress Predictions on Structural Wood Screws

Substitution of Lag Screws with Wood Screws

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