Cutting a cast iron slab?

[Oldmanandhistoy]

Hi all,

Any one got any idea how I could cut through a 2 1/2” x 20” x 30” slab of cast iron with out industrial machinery?

Please don't say an hack saw and a lot of time

John

[jpgdesigns]

abrasive disk in circular saw... clamp on guide and go.

[Oldmanandhistoy]

Originally Posted by jpgdesigns abrasive disk in circular saw... clamp on guide and go.

Hi

Would that be safe and how long would 20” take to cut via this method hrs?

John

[Weldtutor]

Originally Posted by Oldmanandhistoy Any idea how I could cut through a 2 1/2” x 20” x 30” slab of cast iron?

Air-carbon arc (Arcair) will cut through the slab of cast iron.

Some information is HERE.

Research the process to see if it meets your requirements. It's much faster than a hacksaw!

[Geof]

Cutting through the entire 2" thickness is going to be slow and probably go through a lot of abrasive blades.

How good do you want the edges and where is the cut? If the cut is near the middle and you can accept rough edges you could cut a shallow groove, something like 1/4" deep. Now with a bit of luck if you let the slab fall with the groove down so the end lands on a thin piece of wood it will break.

Or you prop one end on a piece of wood and drive your car onto it.

[Oldmanandhistoy]

Thanks Weldtutor

Hi Geof,

Breaking is not an option and the edges will be milled flat straight.

Does anyone think a saw with one of the new metal cutting blades might do the job?

I would have about 5 cuts to make

I think this may be madness

John

[Geof]

Originally Posted by Oldmanandhistoy .....I think this may be madness John

Yes I agree but I have done many mad things in the past so I will continue to encourage you.

Cast iron has to be machined much slower than steel, but in some ways it is easier to machine, or at least some types are. Do you know what this slab is? If it is ductile cast iron or malleable cast iron trying to cut it is only slightly mad. If it is grey cast iron trying to cut it is a bit madder. If it is white cast iron I am coming over to lock you up.

My guess is that it is likely to be ductile or malleable so I will continue.

A triple chip metal cutting blade would die almost instantly if you tried cutting at normal table saw speeds, however if you could slow things down considerably and if you could keep a nice steady feed through the blade your stand a good chance.

Can you rig up some method to slow down your saw? A couple of jackshafts with a 10 : 1 reduction ratio through a few pulleys to drop the speed down to 200 or 300 rpm or maybe lower.

Then clamp a couple of strips of wood on the table on both sides of the slab so it will not twist on the blade and take a cautious cut only about 1/2" deep and see how things go. If things go smoothly get more ambitious.

[Oldmanandhistoy]

All I know is its from a very old marking out table.

I'm thinking one of those hand held saws with http://www.toolstoday.com/c-326-stee...aw-blades.aspx something like this?

John

[Cruiser]

If you have to do it in your home shop then possibly you could set up some guides and use a router and 1/4" end mill, but it will take many passes as you can't take a big bite ! but it would probably be easier than using Abrasive wheel as the wheel will likely want to bind if it is not totally rigid. I used a router and carbide end mill to run a cleanup on both sides of my collumn and some clearances within my box and it worked pretty good. Can't take a lot of depth per pass but you can rip each pass real quick so it may not take too long at all. Use a good carbide cutter to handle the higher speed of router and wear a face shield over glasses, and use mask too. The dust will go everywhere.

[HuFlungDung]

This sounds like a job for someone with a large bandsaw. Even a small band type sawmill would do, provided they could really slow the band speed down, which might require some additional rigging to accomplish. You'd have to buy them a bimetal band though.

[Andre' B]

Great great grand pop would have used a hammer and chisel. Cut a grove on each side and one good smack with a big hammer and you have two parts, works even better in the winter when things are well below zero.
Then throw them on the shaper/planner and square up the edges. If the shaper/planner was big enough he could use that to cut the grooves.

Likely would have been a lot faster then you think, but then gramps had a lot more arm muscle then your average machinist today.

[Geof]

Originally Posted by Oldmanandhistoy All I know is its from a very old marking out table. I'm thinking one of those hand held saws with http://www.toolstoday.com/c-326-stee...aw-blades.aspx something like this? John

If it is a marking out table it is most likely ductile iron so that is okay.

The problem with using a hand saw with one of those blades is the speed. Even with carbide tips you have to go slow on cast iron. Part of the problem is that if the cast iron gets red hot, which it can do in a small region right at the cut when the blade is running too fast, it chills quickly due to the large bulk of material behind. The procedure for making white cast iron is to chill it from a high temperature so guess what you finish up trying to cut when you go too fast. Actually things can go downhill very fast and you may end up with fragments of blade welded into the cut and other fragments located in other areas; sometimes the other areas hurt.

Seriously; I think trying to cut it with a hand saw using any blade is approaching white coated men madness.

Cruiser's router idea is quite sane provided you can get the speed down into the less than 1000 rpm region.


Before I had looked at your link I wondered if it was a Sawz-All. This tyoe of thing:

Amazon.com: Milwaukee 6537-22 Super Sawzall with Quik-Lok Blade Clamp: Home Improvement

Amazon.com: Milwaukee 6537-22 Super Sawzall with Quik-Lok Blade Clamp: Home Improvement

With a bimetal blade you may be able to do it provided you control the blade speed. The Milwaukee unit pictured has a speed preset so you can avoid going to fast and is quite a good unit. (I am biased, I have one) It is not cheap.