1. The average life of farm machines on Iowa farms varies from 8 years for a spring-tooth harrow to 24 years for the farm wagon An average life for all machines is 15.2 years.

2. The life of individual machines varies much from the average. The average life of grain binders, for illustration, was found to be 16 years, but machines were found which lasted only 5 years; while others had a life of 33 years.

3. The average annual service of farm machines in days of use is very low, varying from 4 days for the seeder to 80 days for the wagon and gasoline engine. The average annual use of all farm machines is 16 days.

4. With few exceptions, the life of farm, machines is not directly influenced by the number of days used per year.

5. The annual cost of repairs varies from ¹/₂ of one percent of first cost for the roller, seeder and spring-tooth harrow, to 5 percent for one-row cultivators.

6. The average cost of service for one day varies from 8 cents for the one-row cultivator to $10.11 for ansilage cutter.

7. The most important factor in reducing the cost of each day’s service is a large number of days of use per year.

8. The total annual cost of a farm machine varies from 12 percent to 21 percent of the first cost.

9. While the housing of farm machinery is desirable, systematic repairing has more influence on the life of farm machines.

10. A well-equipped farm shop is a definite aid to systematic repair of farm machines.