Classification Based on Modulus of Elasticity:
Young's modulus is resolute by conducting bending test. On this basis timber is classified as following:
Group A: E = 12.5 kN/mm^{2}
Group B: E = 9.8 kN/mm2 to 12.5 kN/mm^{2}
Group C: E = 5.6 kN/mm2 to 9.8 kN/mm^{2}.