>>8623031I use these, they work suprisingly well in my x-acto knife despite not being the same brand just put a little tape on the side and they fit snuggly saws right through plastics and wood and foam
https://www.amazon.com/Zona-39-925-Replacement-Blades-5-Pack/dp/B000MDLFNQ/ref=mp_s_a_1_4?dchild=1&keywords=xacto+saw+blade&qid=1607730756&sr=8-4