The ESE K9 Power Seamer comes from the factory set with clearance for .032 Aluminum max. The spacing between the second forming roll (R2) and the camfollower above that station limit the space for material. However, the K9 can be converted to run .040 Aluminum.
When the aluminum is folded over to the first stage it is actually three times the material thickness. Also, there is a cleat between the male and female legs adding additional thickness. The image shows material too big to fit between R2 and the camfollower.
K9 Power Seamers are shipped with an optional washer for seaming .040. Part number K9-243B can be installed between R2 and the flange on the driveshaft. It will increase the gap between R2 and the camfollower.
Use an allen wrench (also supplied with the seamer) to loosen the flat head socket cap (FHSC) screw that holds R2 onto the seamer. The roll can then be removed. NOTE: The delrin washer between the screw and roll might come apart separately or stay in the roll depending on wear.
With the washer installed the gap between R2 and the camfollower increases enough to seam .040 aluminum.
In the image above the material is able to pass through the R2 station with no interference. This step is important when single locking or double locking .040 aluminum. To single lock .040 aluminum there are R3 and R4 rolls to convert the K9 to a single lock seamer. To double lock .040 aluminum there are custom R3 and R4 rolls that should be installed.