The Faithfull Engineers Square has been carefully crafted from high quality tool steel, these squares are accurate to BS939 Grade B standard. The stock and blade are precision ground to ensure straightness and accuracy, and the spring steel blade is hardened and tempered for increased durability. Size: 75mm (3in) External size: 95 x 60mm Internal size: 75 x 41.5mm Stock thickness: 8.5mm Blade thickness: 1.7mm FAIES3