A primary purpose of this study was to establish data on hand strength by Jamar dynamometer for normal Finnish adults aged 30 to 50 years. A second aim was to find out how five various breadths of grip affect the strength value. A sample of 103 male and 101 female adults, aged 19 to 62, from the southern part of Finland were tested using standardized positioning and instructions. Male and female subjects reached the highest grip strength using the third handle breadth of dynamometer, except females over 50 years. Female grip strength was 60% to 70% less than male grip strength. There was no significant difference in strength between dominant and non-dominant hands.