Sprue plate bolt

That tends to be a good idea… You might also want to look at the spare screws in the NOE store … of which there are still currently 4 sets currently in stock … 

https://noebulletmolds.com/site/shop/bullet-casting-reloading/specialty-moulds/blank-moulds-parts/replacement-screws/

OBTW … Al tends to use the curved washer to help hold the sprue plate down flat against the mould body is also listed on the screw spare parts page to help keep tension on the sprue plates themselves, plus … all of the NOE moulds that I have also have a set screw in the sides of the mould to help hold the sprue plate screws firmly in place … once the screws are adjusted to your personal specifications.

Those two socket head screws are also identical , & it is also been my observation that the sprue plates are uniform in sprue hole placement … so with the identical screws you always may just have a second screw on hand … This plus the fact that … the NOE moulds are … by the way … machined so that the sprue plate can be installed in either direction on the mould body … as one might wish … Most all of the NOE competitors are not so uniformly oriented … So beware … if you remove the sprue plate on other brands that you remember which way you took the sprue plate off of .. ON the NOE moulds … if push comes to shove … the sprue plate stop screw can be swapped for the worn out sprue plate hinge screw, that you may have filed flats on … to be able to get you back into business until you can get your spare part screws ordered …  Lastly it has been my observation that the set screws that NOE installs to hold both of the above sprue plate screws in place tend to work rather well … Many other brands of moulds do not have such set screws to hold the sprue plate screws in place…