Well.... Todd, you know how McMasters website is. For some reason, you can't post a link to a specific part, just the main part list page.
Here is the spring pin page:
https://www.mcmaster.com/#standard-spring-pins/=1a4g65d
I ordered the steel coiled spring pin. Part# 91598A482.
I suggest ordering the Heavy Duty Coiled Spring Pin. Part# 95755A415.
Instead of 50 in a pack, you get 25, but the cost is still pretty manageable.
You get about 21 more pins for the same money as you can spend with MTD, lol.