Mechanical properties of natural fibers can be strongly affected and determined by several important variables such as structure, microfibrillar angle, chemical compo­sition, cell dimensions, and defects (Azwa et al. 2013 ; Dittenber and GangaRao 2011; John and Anandjiwala 2007; Wong et al. 2010). Microfibrillar angle is the angle between fiber axis and the micro-fibrils. These angles are responsible for the mechanical properties of the fibers. The smaller the angle the higher strength and stiffness of the fiber while larger angles provide usually higher ductility. Generally, natural fibers with higher mechanical strength possess higher cellulose content, lon­ger cell length, higher degree of polymerization of cellulose, and lower microfibril­lar angle. Important mechanical properties like tensile strength and Young’s modulus usually increase as cellulose content and cell length increase (John and Thomas 2008; Methacanon et al. 2010). The mechanical properties of the date palm fiber and other natural fiber types can be shown in Table 1.4.