• Technical Blogs
  • Jul 11, 2022

Tips & Tricks—Build Your Installation Jigs for 45⁰ & 90⁰ Structural Fasteners

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Modern Mass Timber Design concepts have become more versatile with the use of structural fasteners arranged at varying angles to the wood grain. The most common angle to the grain, or fastener axis-to-force relationships, of 45- and 90-degrees are used to allow for a broad and cost-effective range of connection performances in designs, with respect to strength, stiffness, and ductility.

The integrity of the connection design also relies on accurate fastener installation on site. Basic and simple tools are an effective way of increasing installation accuracy considering limited training and fundamental concepts of craftsmanship. This blog post highlights a proven step-by-step method to fabricate a predrill jig for fastener installation at the most common angles of 45- and 90-degrees.

Approximately 6-min read


Basic Theory for 45⁰ & 90⁰ Fastener Configuration

If you are only looking for the hack, jump directly to the section 45⁰ & 90⁰ Predrilling / Installation Jig fabrication.

The performance properties in connection design are, besides many others, a function of the angle to grain relationship between the fastener axis and the wood grain and/or the force to fastener axis relationship. It is known that inclined full-thread fasteners, arranged at 45⁰ to the force direction, are acting in withdrawal and exhibit higher capacity and stiffness when compared to threaded fasteners acting in typical shear applications. Shear applications can be defined where the force component is acting perpendicular to the fastener axis; they are also known to exhibit more ductile behaviour at the loss of capacity and stiffness. Either fastener arrangement requires certain installation practices and is adding value to the engineer’s toolbox and the integrity of the connection.

Practical experience has indicated that installation tolerances of +/-3⁰ can be realized on-site without sophisticated jigs and tools. Most standard connections will perform within the desired limits in this acceptable tolerance range; however, when outside of these tolerance specifications one may expect connection performances to be influenced and design professionals should be consulted for evaluation. To assure accurate repetitive installation of large volumes of fasteners in mass timber buildings, the use of predrill jigs or other assisting tools is recommended. Installation recommendations can be found in our latest blog on how to install MTC Solutions fasteners.

The fabrication of the simple predrill/installation jig demonstrated in this blog post can assist with accurate fastener installation, better connection performance, and less cost through reduced repair or on-site corrections.


45⁰ & 90⁰ Predrilling / Installation Jig fabrication
Approximate construction time: 15 min

Please note that the following instructions are brief and may not be complete for all circumstances. Only qualified personnel should perform these tasks with the appropriate training, proper tools, and safety equipment.

Tools and Material

  • Speed square
  • Handsaw or table saw
  • Pencil
  • plywood
  • Drill
  • Drill bit
  • Screws
  • Personal Protection Equipment

Fabrication guidelines

1.Layout & cut a rectangle
Using the speed square, mark out a rectangle on your plywood. After, use the table saw to cut the rectangle.

2.Mark the angle
Find the middle of the rectangle and draw a 45⁰ line through it using your speed square.

3.Set the blade
Set the table saw blade to 45⁰ to mitre cut the edge.

4.Cut in half
Set the table saw fence to 45⁰ and the blade to 45⁰, cut the rectangle along the 45-degree line to create the beveled edge.

Align and assemble the two pieces with screws.  Mitre cuts facing each other creating a grove


90⁰ Predrilling /Installation Jig Fabrication

For the 90⁰ jig, follow steps as per the 45⁰ jig fabrication until step 4, then proceed as follows:

1.Mark the line
Using the speed square, take one of the two pieces of the jig and draw a line 3/8” away from the shortest side of the trapezoid.

Using the table saw cut the board following the line.

Align the two pieces, making sure that the inclined side is lined up, to create an offset on the opposite side. Screwing the two pieces using the power drill and screws.


For more details on how to install MTC fasteners, download our Structural Screw Catalog.

For any questions, contact our Technical Support Team 😉.

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