Flat Washer Head Partially Threaded Structural Wood Screws, 3.0
  • Code Approval
  • ICC, ETA
  • Connection Type
  • Wood/Wood
  • Applications
  • Timber Framing, Log Home Building, Mass & Heavy Timber Construction
  • Manufacturer
  • SWG

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Flat Washer Head

Shank Cutter

Partially Threaded

Counter Thread Tip

Product Description

Product Description

The ASSY FWH 3.0 are partially threaded high performances structural fasteners. They are ICC-ESR [3179] approved fasteners, designed to pull tightly together connection elements.

They are two-in-one engineered screw that combines the pulling power of a washer-head screw with the clean finish of a countersunk head screw. Their design offers a precise setting without the need for pre-drilling [may be recommended for long models].

Their blue passivated zinc coating makes them adequate for use in low corrosive environment, such as dry service condition. They participate in LEED BD+C 2.0 certification [MRc 4.1 & 4.2, 2 points possible] thanks to the percentage of post-consumer recycled steel used to manufacture them.



Diameter 5/16″ (8 mm)
Lengths 6-1/4″ (160 mm) to  15-3/4” (400 mm)
  • Partially threaded structural fasteners 3.0
  • Installed with AW Bits
  • Flat washer head for a clean architectural finish
  • Ideal for wood-to-wood connections
  • Blue passivated zinc coating
  • Counter thread tip providing a fast fastener wood bite & installation
  • Equipped with a shank cutter reducing the installation torque needed
  • LEED certification letter available upon request




SpecificationASSY F.W.H.Thread LengthDrive BitPackaging Qty.
# ItemMaterialHead
[3] FWH08100Hardened Steel Flat Washer Head5/16 x 48 x 1003 1/880RW 4050
[3] FWH08160Hardened Steel Flat Washer Head5/16 x 6 1/48 x 1603 1/880RW 4050
[3] FWH08200Hardened Steel Flat Washer Head5/16 x 7 7/88 x 2003 1/880RW 4050
[3] FWH08240Hardened Steel Flat Washer Head5/16 x 9 1/28 x 2404100RW 4050
[3] FWH08300Hardened Steel Flat Washer Head5/16 x 11 7/88 x 3004100RW 4050
[3] FWH08360Hardened Steel Flat Washer Head5/16 x 14 1/48 x 3604100RW 4050
[3] FWH08400Hardened Steel Flat Washer Head5/16 x 15 3/48 x 4004100RW 4050
CAD Drawings

2D & 3D Geometry

ProductASSY FWH DiameterFile Extension
Design Guides

Design Guides

Structural Screw Catalog

A catalog with all information on our ICC & CCMC code-approved fasteners, including dimensions, references & design properties.

Structural Screw Connection Design Guide

Companion to the Structural Screws Catalog, it provides easy-to-read tables for the most common mass timber connections with design values & installation instructions.

Code Approvals

Code Approvals

ICC Code Approval ESR-3179 for Partially Threaded Fasteners - 2022 Edition (October)

CCMC Code Approval 13677-R

ISO 50001 Certification for ASSY Fasteners

LA Research Report (LARR): RR 26073

White Papers

White Papers

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

Technical Blogs

Technical Blogs

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