I tend to use clearance slots a number of times on my mating parts to allow for movement and have a practice of adding two washers(a plain washer and a spring washer, one over the other) followed by the bolt. Currently, the process I use is to add a plain washerto the assembly first and then add a spring washer, and the bolt later. Is there a way I can put in both plain and spring washers both at the same time when i am fastening over slot? Any help is greatly appreciated!