Self-Drilling Dowel

Cylinder Head Fastener for Internal Knife Plate Connections
  • Connection Type
  • Wood/Steel
  • Applications
  • Mass & Heavy Timber Construction

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Concealable Head

Partially Threaded

Self-Tapping Tip

Product Description

Product Description

The SDD Self-Drilling Dowel is a cylinder head dowel fastener designed for timber connections with knife plates. Its unique drilling tip eliminates the need for pre-drilling in wood, aluminum, and thin (< 1/8”) steel plates. It is made of hardened steel, resulting in higher shear resistance than non-hardened dowels.


Diameter 1/4″ (6.9 mm)
Lengths 2-7/8” (73 mm)  to  9-1/8” (233 mm)
  • Cylinder head dowel
  • Hardened steel
  • Continuous thread
  • Easy to install with a cordless drill

Its low installation torque makes the SDD easy to install with a cordless drill without the need for additional equipment. The continuous thread ensures a tight fit that reduces slip in critical connections and helps drive the dowel forward reducing the amount of force needed for installation. MTC Solutions’ SDD is designed to be used with AW 40 drill bits for exceptional fit and durability. The cylinder head can be easily plugged with a wooden dowel.



SpecificationSDDThread LengthDrive BitPackaging Qty.
# ItemMaterialHead
SDD0673Hardened Steel Cylinder Head0.27 x 2 7/86.9 x 731 1/431AW 4050
SDD0693Hardened Steel Cylinder Head0.27 x 3 5/86.9 x 931 5/840AW 4050
SDD06113Hardened Steel Cylinder Head0.27 x 4 1/26.9 x 113250AW 4050
SDD06133Hardened Steel Cylinder Head0.27 x 5 1/46.9 x 1332 3/860AW 4050
SDD06153Hardened Steel Cylinder Head0.27 x 66.9x 1532 3/470AW 4050
SDD06173Hardened Steel Cylinder Head0.27 x 6 3/46.9 x 1733 1/880AW 4050
SDD06193Hardened Steel Cylinder Head0.27 x 7 5/86.9 x 1933 1/290AW 4050
SDD06213Hardened Steel Cylinder Head0.27 x 8 3/86.9 x 2133 7/8100AW 4050
SDD06233Hardened Steel Cylinder Head0.27 x 9 1/86.9 x 2334 3/8110AW 4050
CAD Drawings

2D & 3D Geometry

ProductFile Extension
Self-Drilling Dowel
Design Guides

Design Guides

Structural Screw Catalog

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

Installation Instructions

Installation Instructions

Self-Drilling Dowels [SDD] Installation

Learn how to install MTC Solutions Self Drilling Dowels in this video showcasing an internal knife plate installed in CLT material.

Technical Blogs

Technical Blogs

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