study and comparison of the hardness of some iran made reciprocating mower blades

cutting blades are exposed to abrasion and breakage during operation. therefore a comparison of such mechanical properties as hardness among different blades is necessitated. in this research, the hardness of three iran made blades (khooshe-talaei, iran-derogar and combine-sazi) and two foreign (germany and u.s.a) manufactured ones were evaluated and compared with the standard figures. the results showed that, maximum and minimum mean values of blades’ edge hardnesses were 77.81 hra and 75.78 hra respectively for american and german blades. there was no significant difference observed between edge hardness in iranian and american blades. blades edge hardnesses for all producers matched the standard values. in a comparison of blades’ middle layer hardness, the maximum and minimum mean values were 55.88 hra and 52.29 hra respectively for american and iran-derogar made blades. none of the samples met the standard middle hardness requirement.