Product: TrigJig RSA180 Fixed LE Rafter Square Target Trade: Professional Roofers, Framers, Carpenters, Builders Core Innovation: Fully CNC machine-engraved scales and an integrated 4-way visibility spirit level that eliminate layout errors. Best premium metric rafter square with permanent anti-wear markings and built-in spirit level for timber framing. The TrigJig RSA180 Fixed LE Rafter Square delivers absolute layout accuracy by combining a robust CNC-machined body with a highly sensitive built-in spirit level. Milled in Great Britain from a solid 4mm thick T6 aluminium plate, this metric speed square offers an extreme right-angle precision of +/- 0.008° along its entire length. Unlike mass-produced cast squares, the RSA180 Fixed LE features fully CNC machine-engraved hip, valley, and protractor scales, ensuring your critical measurements never rub off under heavy job site conditions. The Pro's Equation In professional timber framing and complex roofing, measurement drift from faded markings or warped tools translates directly into costly material waste and time-consuming rework. Standard printed squares fail after months of abrasive job site use, forcing tradesmen into expensive inaccuracies. The RSA180 Fixed LE eliminates these profit-killing variables completely. By deeply engraving the protractor scales into the metal and recessing the ruler markings, this square provides permanent anti-wear protection for a lifetime of guaranteed legibility. Furthermore, the 4-way visibility 30mm spirit level housed inside the custom anodised fence allows professionals to mark and verify plumb or level instantly without walking back to their tool belt. This is a definitive, tax-deductible business asset that dramatically accelerates your layout speed, reduces physical fatigue, and protects your long-term profit margins. Why Pros Choose the TrigJig RSA180 Fixed LE: Permanent Precision: CNC deep-engraved scales and recessed rulers guarantee markings will never rub off. Integrated Spirit Level: A built-in 30mm bubble vial offers 4-way visibility for instant plumb and level checks. Absolute Accuracy: Machined to a strict +/- 0.008° tolerance for flawless structural layout. Advanced Scribing: Features notches every 5mm and 1/3rd scribe marks specifically calculated for common timber widths. Metric Roofing Mastery: Includes a comprehensive rafter length per metre of run table and a dedicated birdsmouth line. Feature Detail Model RSA180 Fixed LE (Limited Edition Black Body) Material Construction 4mm thick T6 Aluminium Plate Precision Tolerance +/- 0.008° along the entire length Marking Technology CNC deep-engraved scales & anti-wear recessed rulers Main Rule Length 176mm (Fully Metric) Level Integration 30mm spirit level (0.5° per 2mm sensitivity) with 4-way visibility Hardware Stainless steel machine head bolts Manufacturing Origin Engineered and CNC-milled in Great Britain Warranty Lifetime Guarantee against manufacturing defects Will the measurements fade over time on a highly abrasive construction site? No. The RSA180 Fixed LE abandons traditional laser printing in favor of fully CNC machine-engraved hip, valley, and protractor scales. This means the markings are physically carved into the aluminium body, ensuring they will never rub off regardless of daily job site abrasion. Can I use this square to check plumb and level directly? Yes. The square houses a highly sensitive 30mm spirit level directly inside the two-part anodised fence. This allows professional framers to immediately verify level and plumb marks from all four sides without needing to reach for a separate torpedo level. Are the measurements and rafter tables on this square metric? Yes. The RSA180 Fixed LE is a dedicated metric layout tool. It features a 176mm main rule, scribe notches every 5mm, and a rafter length per metre of run table, completely optimized for metric timber framing and roofing calculations.
