Small clear test specimens with different width to pin-diameter ratio (l/d) were loaded for creep rapture and time to failure was discussed in terms of the effect of length to pin-diameter ratio. The time to failure of the test specimens with l/d from 6.7 to 10 was longer and that of the test specimens with l/d from 4.3 to 6 was shorter than the time to failure estimated by the Madison Curve. The test results indicated that the duration of load factor for the tested joints should be evaluated with consideration of the effect of the width to pin-diameter ratio.