Abstract
Fatigue tests on the three strand roller chains having various fitting conditions between middle link plates and pins were made. Results are as follows:
1. The fatigue strength of treble strand M-type roller chains (standard) having clearance between middle link plates and pins is twice as that of single strand chains.
2. The fatigue strength of treble strand P-type roller chains having interference between middle link plates and pins is 2.4 times as large as that of single strand chains.
3. The endurance ratio of multiple strand roller chains is smaller than that of single strand roller chains.
4. The fatigue strength reduction factor due to increase of strands is nearly independent to the number of cycles to estimate the fatigue strength.
5. The fatigue strength reduction factor takes the smallest value at P-type. M-type is the next. The value is the largest at L-type.
6. The load distribution for the each strand seems to be nearly uniform at P-type, considering from the form of destruction. In the other types, it seems to be not uniform.
