Cylinder Head Fully Threaded Self-Tapping Wood Screw
  • Code Approval
  • Connection Type
  • Wood/Wood
  • Applications
  • Timber Framing, Log Home Building, Mass & Heavy Timber Construction
  • Manufacturer
  • SWG

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Cylinder Head

Fully Threaded

Tapping Tip

Wood Reinforcement

Product Description

Product Description

The ASSY VG Cyl (Cylinder Head) screw is a fully threaded self-tapping wood screw engineered for timber reinforcement, beam repair, and connections where a small head is required for a clean, concealed, architectural finish.

Code-approved reliability, the ASSY VG Cyl screw has been awarded an ICC-ESR approval in the United States and the Canadian Construction Materials Centre Reports (CCMC) approval in Canada.  



Diameters1/4″ (6 mm) , 5/16″ (8 mm) , 3/8″ (10 mm)
Lengths3-1/8″ (80 mm)  to  31-1/2” (800 mm)
  • Small cylindrical head almost invisible when installed
  • Easily concealable with a wood plug
  • Zinc coating designed for dry service condition
  • Aggressive drill tip mimics a drill bit and bites into the wood and assures quick and easy installation
  • Ideal for incline wood-to-wood connections and wood reinforcement
  • Can be used in Timber Concrete Composite systems, potentially replacing ASSY VG CSK
  • For more connection examples and information see our Design Guides
  • All ASSY fasteners can 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. LEED certification letter is available on request.

The range of available lengths and diameters makeS the ASSY VG Cyl suitable for a broad range of projects from log home building to multi-story mass timber construction. The ASSY VG Cyl screw can also be used in beam upgrades and connections where a small screw head is required. ASSY fully threaded screws can be used in typical reinforcing applications, including checked or cracked members, potentially restoring them to nearly their full original strength following our Timber Reinforcement Guide.



SpecificationASSY VG CYL   Thread Length AW Drive BitPackaging Qty.
# ItemMaterialHead
CYL0680Hardened SteelCylinder Head1/4" x 3 1/8"6 x 802 7/8"73AW 30100
CYL06100Hardened SteelCylinder Head1/4" x 4"6 x 1003 5/8"93AW 30100
CYL06120Hardened SteelCylinder Head1/4" x 4 3/4"6 x 1204 1/2"113AW 30100
CYL06140Hardened SteelCylinder Head1/4" x 5 1/2"6 x 1405 1/4"133AW 30100
CYL06160Hardened SteelCylinder Head1/4" x 6 1/4"6 x 1606"153AW 30100
CYL06180Hardened SteelCylinder Head1/4" x 7 1/8"6 x 1806 3/4"173AW 30100
CYL06200Hardened SteelCylinder Head1/4" x 7 7/8"6 x 2007 5/8"193AW 30100
CYL08120Hardened SteelCylinder Head5/16" x 4 3/4"8 x 1204"104AW 4050
CYL08140Hardened SteelCylinder Head5/16" x 5 1/2"8 x 1404 7/8"124AW 4050
CYL08160Hardened SteelCylinder Head5/16" x 6 1/4"8 x 1605 5/8"144AW 4050
CYL08180Hardened SteelCylinder Head5/16" x 7 1/8"8 x 1806 1/2"164AW 4050
CYL08200Hardened SteelCylinder Head5/16" x 7 7/8"8 x 2007 1/4"184AW 4075
CYL08220Hardened SteelCylinder Head5/16" x 8 5/8"8 x 2208"204AW 4075
CYL08240Hardened SteelCylinder Head5/16" x 9 1/2"8 x 2408 7/8"224AW 4075
CYL08260Hardened SteelCylinder Head5/16" x 10 1/4"8 x 2609 5/8"244AW 4075
CYL08280Hardened SteelCylinder Head5/16" x 11"8 x 28010 3/8"264AW 4075
CYL08300Hardened SteelCylinder Head5/16" x 11 7/8"8 x 30011 1/8"284AW 4075
CYL08330Hardened SteelCylinder Head5/16" x 13"8 x 33012 3/8"314AW 4050
CYL08360Hardened SteelCylinder Head5/16" x 14 1/4"8 x 36013 1/2"344AW 4050
CYL08380Hardened SteelCylinder Head5/16" x 15"8 x 38014 3/8"364AW 4050
CYL08430Hardened SteelCylinder Head5/16" x 17"8 x 43016 1/4"414AW 4025
CYL08480Hardened SteelCylinder Head5/16" x 19"8 x 48018 1/4"464AW 4025
CYL08530Hardened SteelCylinder Head5/16" x 20 7/8"8 x 53020 1/4"514AW 4025
CYL08580Hardened SteelCylinder Head5/16" x 22 7/8"8 x 58022 1/4"564AW 4025
CYL10120Hardened SteelCylinder Head3/8" x 4 3/4"10 x 1204 1/8"105AW 5050
CYL10140Hardened SteelCylinder Head3/8" x 5 1/2"10 x 1404 7/8"125AW 5050
CYL10160Hardened SteelCylinder Head3/8" x 6 1/4"10 x 1605 3/4"145AW 5050
CYL10180Hardened SteelCylinder Head3/8" x 7 1/8"10 x 1806 1/2"165AW 5050
CYL10200Hardened SteelCylinder Head3/8" x 7 7/8"10 x 2007 1/4"185AW 5050
CYL10220Hardened SteelCylinder Head3/8" x 8 5/8"10 x 2208 1/8"205AW 5050
CYL10240Hardened SteelCylinder Head3/8" x 9 1/2"10 x 2408 7/8"225AW 5050
CYL10260Hardened SteelCylinder Head3/8" x 10 1/4"10 x 2609 5/8"245AW 5050
CYL10280Hardened SteelCylinder Head3/8" x 11"10 x 28010 3/8"265AW 5050
CYL10300Hardened SteelCylinder Head3/8" x 11 7/8"10 x 30011 1/4"285AW 5050
CYL10320Hardened SteelCylinder Head3/8" x 12 5/8"10 x 32012"305AW 5050
CYL10340Hardened SteelCylinder Head3/8" x 13 3/8"10 x 34012 3/4"325AW 5050
CYL10360Hardened SteelCylinder Head3/8" x 14 1/4"10 x 36013 5/8"345AW 5050
CYL10380Hardened SteelCylinder Head3/8" x 15"10 x 38014 3/8"365AW 5050
CYL10400Hardened SteelCylinder Head3/8" x 15 3/4"10 x 40015 1/8"385AW 5050
CYL10430Hardened SteelCylinder Head3/8" x 17"10 x 43016 3/8"415AW 5025
CYL10480Hardened SteelCylinder Head3/8" x 19"10 x 48018"456AW 5025
CYL10530Hardened SteelCylinder Head3/8" x 20 7/8"10 x 53019 7/8"506AW 5025
CYL10580Hardened SteelCylinder Head3/8" x 22 7/8"10 x 58021 7/8"556AW 5025
CYL10650Hardened SteelCylinder Head3/8" x 25 5/8"10 x 65024 5/8"626AW 5025
CYL10700Hardened SteelCylinder Head3/8" x 27 5/8"10 x 70026 5/8"676AW 5025
CYL10750Hardened SteelCylinder Head3/8" x 29 1/2"10 x 75028 5/8"726AW 5025
CYL10800Hardened SteelCylinder Head3/8" x 31 1/2"10 x 80030 1/2"776AW 5025
CAD Drawings

CAD Drawings

ProductASSY VG CYL DiameterFile Extension
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 3178 for Fully Threaded Screws - 2021 Edition

CCMC Code Approval 13677-R

ISO 50001 Certification for ASSY Fasteners

LA Research Report (LARR): RR 26072

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 Reinforcement Guide

Notch Reinforcement Design USA

Design for Reinforcement of Perpendicular to Grain Connection

Designing Timber Concrete Composite Systems (TCC) with ASSY Self-Tapping Screws

Purlin to Beam Connections Using ASSY Fully Threaded Fasteners

Roof-to-Wall Connections (Truss Uplift)

ASSY Screws vs. Lag Bolt

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

4D+ Embedment Reduction Factor for Screws Loaded in Withdrawal

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