Breaking slate slabs

I would be tempted to cheat a bit. Do a through cut slightly wide of where you need it with a large AG with a diamond disc - slate cuts very nicely like this. Then use a chipping hammer or hammer and bolster to chip away at the cut edge to give it the riven or broken finish that you want.

Ask the supplier.

Bill

You obviously need a Karate practitioner. I used to work with on lady who could break about 10 at a time with her elbow. grin. I said to her once, so I know who to call if anyone attacks me with a slate tile then. I got a very sarcastic reply.

I often wonder if her elbow still works. Brian

Depending on what sort of look you want you probably want a bolster chisel to cut them. It should be enough to cut a line where you want it to break support either end and whack it hard in the middle.

So long as you can live with rough edges and some not breaking where you intended that ought to be good enough. You can also split slate into thinner pieces very efficiently with such a chisel. Method is essentially the same create a weakened line and then one good hit.

Cut a weakened line first with the bolster, turn it over then whack it. (or as John suggests use an angle grinder to weaken it)

You still get 3 rough broken edges if you cut it that way.

It is, in the first instance.

Use a diamond tool - either on your existing angle grinder - or hire a big 'un - to get the shapes roughed out, then 'distress' the edges with a hammer and cold chisel or similar. 'Angry' pliers can also be used to break bits off the edges for added rusticity,

Many thanks for all the suggestions. In order to even unload the pallet, I had to attack some of the largest stones just to move them. Some were thin enough for my 4" angle grinder to weaken adequately for the rest to break away, others responded OK to the bolster and split into thinner, lighter sections.

Looks like there is plenty for me to do.

I did ask the supplier, and they said

"You could try tapping with a chisel in a line along the middle to ?shock? the slate. You will need to repeat this process several times but there is no guarantee how the slate will split.

Another alternative is to smash the edge with a heavy mallet at a slight angle to break off pieces of slate. This is a slower process but should give the end result.

I have also sawn slate in the past for signs and then the client has requested the edges to be natural. Hitting the edge with the pointy end of a brick hammer will also give a more rough natural finish."

A brick hammer I have, but a larger angle grinder just for this job seems overkill. Perhaps I need a bigger hammer. ;-)

Chris

I can assure you that my small 5" AG with a diamond blade eats through sandstone, which is harder than slate, quite a lot faster than it eats through its diamond coating.

Another option is to use to a diamond blade on the reverse side then crack the slate along the line