407FK4 Tsumura Light Type 20[50cm] 3/8 .058 72 drive links

Tsumura chainsaw bars are manufactured and assembled using advanced technology machines and salt heat treatment to provide high standards of durability, strength, finish and accuracy. They incorporate uniform groove gauge tolerances for precise chain fit and improved cutting stability over the bar nose.   Guide bars require both of contrasting characteristics of toughness and hardness. Tsumura has adopted salt heat treatment that draws both of the contrasting characteristics. The salt bath heat treatment is the best way to achieve ideal steel which has toughness and hardness. Normally, Steel is heated over 800°C immediately, but the salt bath heat treatment provides a gradual steady heat method. Then, a good hardened steel structure, which is stable with less distortion, can be obtained. There are two types of solid guide bar. One has a replaceable sprocket nose and the other has a hard nose. Solid guide bars are manufactured from one plate of super hard alloyed steel SKS-51. Light Type bars have dove-tailed notches that are staggered and cut into the bar surface and packed with hard resin which reduces the weight of the guide bar by about 20%. This improves cutting efficiency and stability and also reduces user fatigue.