The objective of this research is to analyze and evaluate the hand arm vibration exposure of hand held grass
cutter machines during their normal operation time. On-site field measurement for five different types of hand held
grass cutter machines. In this research, the hand arm vibration exposure levels of different machines were measured
at practical cutting condition in accordance to guidelines on occupational vibration which are presented in the
occupational safety and health standard manual. The hand arm vibration level on the worker’s both right and left
handles of the grass cutter machine were measured and analyzed, respectively. The vibration frequency weighting
acceleration was calculated by using h-weighting. The hand arm vibration acceleration value was expressed in the
root-mean-square (rms) combination of all three major axis (ahwx, ahwy & ahwz). The estimated daily vibration exposure,
A(8) were differ between 2.1 to 20.7 ms-2 for right hand while 2.7 to 29.1 ms -2 for left hand. In short, worker will
induce fingers blanching in 10% of the exposed person after less than 3.7 years exposed to hand arm vibration.