EX are letters that are commonly used in the timber industry and can be confusing if you’re not a frequent timber buyer. 

With products like 125 x 22mm 2EX feather edge, or 125 x 47mm 2EX cant rails it can be difficult to know the actual size timber you’re buying. 

When buying timber that isn’t square such as feather edge, which is wedge shaped, the dimensions provided are the dimensions before the end product is produced. 

125 x 22mm is the size of the square plank of timber used to create the individual feather edge boards. The 2 in 2EX is referring the the number of lengths of feather edge milled from each 125 x 22mm plank. 

Another example is a 75 x 75mm length of timber cut diagonally to produce two triangular lengths, this would be described as 75 x 75 2EX.