Best and safest one I saw was the @lordmarcovan technique.... He puts an edge between the gaps on his deck and rocks the slab back and forth until it cracks.
I wrap a rag around the slab and put it in my 8" vise edgewise and then slowly tighten the vise jaws until I hear it crack. If it's not cracked sufficiently to pry it apart then I do it some more until it's reached the point it can be pried open. Key point is that I don't want the slab to fall apart to the point that the coin falls out because even though it's wrapped in a rag, the edges of the broken plastic slab can scratch the coin.
The OP won't see this because he has me blocked, but there is an old thread about cracking slabs. Have you ever cracked a coin out of a slab
https://www.cointalk.com/threads/have-you-ever-cracked-a-coin-out-of-a-slab.205297/#post-1428414 Interesting thread. OP may enjoy it, thanks.
When I was doing it, I did it all wrong. I use my linesman pliers and a small screwdriver. Now I don't bother to crack anything out.
I use the same exact method. It works well but you have to be very careful that the coin doesn't get damaged or scratched. I've never had a problem. Bruce
I’ve got a European medal in an NGC slab. I don’t think TNT and a Sherman tank could get this thing open.
A beautiful medal, Santinidollar. No problem breaking open this type of slab...though I wouldn't personally. The "vice method" I described above would work. Bruce
Too many people overthink it. It is very easy to do, even without tools as I demonstrated. But if you wanna go at it with a vise or whatever else in your toolbox, fine.
