Screw Head Type?

[ChuHeff]

Hello, Not sure this question deserves a new thread of it's own, but didn't know where to post the questions, so here it is. I just purchased a Rock Island vise, model 591. It a great little vise which seems to have had comparatively little use. I am removing the jaws to clean behind and be sure all is good. The static jaw screws are quite tight so I am going to soak those for a few days before giving them a serious go. The dynamic jaw insert screws came out fairly easily. These are Phillips drive screws. One of them has a fairly messed up Phillips drive so I will want to replace it. If possible with the same type and Phillips drive. My question is what is this type of screw called? It has a flat head, but the sloped edges are quite long. The screw in the photo is 3/4" OA length and the head itself is about 5/16" of that length. The head also appears to me to have less slope than a typical machine screw? I have seen these before, but it has been a while and I don't remember where. Thanks for your help!

 

[steaks&anvils]

This has been discussed on one or both of these two threads. They are both very long threads so you will have to spend some time looking.

I believe it has been decided you have to make your own.

https://www.garagejournal.com/forum/showthread.php?t=44782

https://www.garagejournal.com/forum/showthread.php?t=252830&highlight=vises+101

 

[Millwrong]

Yikes! I've never seen a flathead with that steep of an angle. I'm sure the thread is standard, why not bore the jaws out with an 82° countersink and use a typical FHCS?

 

[RTM]

Yup, like steak said, make your own. I used SHCS, spun them down in a drill against the grinder.

 

[ChuHeff]

Hello, Thank you all for your input. Due to jaw size and type on this vise, the best course of action seems like grinding down a cap crew would be best. Being a woodworker, this will be new for me, but looking forward to giving it a go. I'm not even sure why I bought this vise. I already own a fixed base Wilton 930 but this vise is such good shape the I was drawn to it! Thanks again.

 

[Provincial]

If you want to keep a Phillips drive on your replacement screw, start with a Phillips drive "fillister" head screw. That will give you the material you need to make the tapered head. If you can find someone with a small metal lathe, the modification will be easy. If not, the method RTM reported will work well.