[roffey]

Originally Posted by spareparts

they're actually called welch plugs or core plugs even though every one calls them freeze plugs. Their primary purposes to plug the holes in the block that was used to get the sand out when it was cast. They don't have anything to do with freezing other than they push out when you let a block freeze, and no, they won't prevent a block from cracking

Nicely done, Thanks.