The Limited Edition TrigJig RSA300 Adjustable Rafter Square is a large 300mm Rafter Square. 

With enhanced features, we've created it to be top of its class when it comes to design, build quality, usability and style.

As the bigger brother to the RSA180 Adjustable LE, it's ideal if you work with big timber. Developed for quick and simple marking/laying out of roof trusses with a smart adjustable fence that locks in position for speed, ease and repeatability. 

With several marking gauges on the tool's face, the RSA300 Adjustable can be used in many carpentry and fabrication projects, though its speciality is for roofing, timber framing and for use with large trusses and timber.

One  of our best rafter squares yet, the RSA300 Adjustable is manufactured in-house from the highest quality European aluminium. We CNC machine each tool to tight tolerances, with right angle precision of +/- 0.008° along the entire length. 

There are curved scribe notches throughout the length of the tool that relate to many common timber sizes. These can be used with a variety of marking tools such as carpenters pencils, automatic construction pencils or just a standard pencil. These also include thirds for marking rafter cuts. 

An anti-glare anodised surface and enlarged laser etched markings help with outdoor use. The laser marked graduation rulers and parallel scribe scales are recessed in pockets to avoid wear over time.

The degree lines are deep engraved so they won't rub off, and as they are made on the same CNC milling machine that profiles the square, the level of precision is excellent. 

The adjustable silver anodised aluminium fence is also CNC machined and is fixed to the tool via nylon 66 bearings for smooth operation that snaps back to exactly 0°. The fence can be locked in place with a stainless steel thumb screw for repeatable cuts and marking super precise birds mouths, without any repeat measuring required.

There are several features and marking gauges on the face of the tool, including;

• 300mm rule (plus a smaller rule along the fence edge)
• Deep engraved protractor gauge along the hypotenuse edge
• Common rafter and hip/valley rafter gauges in degrees
• Scribe lines for common timber dimensions
• 1/3rd scribe marks for common timber widths
• Rise per metre of run table
• Rafter length per metre of run table

• Constructed from high quality T6 aluminium
• High precision CNC machine profiled
• Adjustable CNC machined aluminium fence
• Anodised protective finish
• CNC laser marked graduation scales
• Made in Great Britain

The precision and workmanship from our manufacturing process is unrivalled and next level compared to mass produced, laser cut or cast rafter squares. The RSA300 Adjustable LE is built to an extremely high standard, made for tradespeople who are looking for exceptional durability, design and quality from their tools. 

Lifetime warranty when registered within 30 days of purchase -read more