How to Make a Hardie Hole

[Jspool]

I would like to place a 1” hardie hole in my work table top.  

The table is made from 2” thick cast iron.

Can anyone suggest a way to do this other than drilling and hand filing?

[Daswulf]

Well aside from more helpful replies you may get on a different method, drilling and filing cast iron isn't all too bad. It's not like you can hot drift it. 

Plasma cutter? Torch would be ugly and have to be under cut then cleaned up. Maybe best taken to a machine shop ? 

[DavidF]

I have seen two methods, but I bet one of the experts will come along with better information. If you have an existing anvil without a hole, the method would be to measure out your lines, then use a drill to get the majority of mass out. Then it is using whatever next best tool, maybe a Dremel, to get close to the corners, and finally some good old fashioned elbow grease with a square file. If you are adding a top, you weld pieces together to for the hardie hole in your strike plate.

[RobS]

Broaching is also an option.

 

[Glenn]

Portable hole near or attached to the work bench

[lyuv]

1. BUILD (weld) a square well, that protrudes above the table. (rather than a hole).

2. If you are not fixed on the shape and size of the hole - consider that the hole is just the connection of the tool to the table. You can make a different and simpler one. Like two 1/2" holes, about 1" apart. The tool will have two matching "legs".

[Stitch]

Perhaps a local CNC wire cutting service?

[Jspool]

All great ideas. I like the idea of a broach but not sure it works on cast iron.

[arftist]

Triangular drill bit,  cuts a square hole.

Grey cast iron is essentially free machining, much easier than steel..

[Smoggy]

You got access to a shaper?

[Joel OF]

I can't help thinking that to own a 2" thick cast iron bench would be an amazing thing and putting a hole in it is asking for trouble. Why does the hole have to be in the bench?

[boisdarc]

drill an oversized hole, cut a piece of square stock. put square stock in the hole, and weld around it. maybe?

[BIGGUNDOCTOR]

Welding cast iron is no walk in the park.

My question is why do you want a hardy hole in your bench? And where in the bench will it be? Cast is brittle, and adding a square hole with sharp corners may be asking for trouble if it is getting pounded on.

[jlpservicesinc]

Best way to do it is drill the hole at 4 corners, then drill out the center.. Then with shims and a broach (just make one) broach the hole..  Be sure to leave the corners with a radius vs sharp.. 

[Jspool]

A little background.

Its a great table (4x4) that use to be a layout table sometime in its past.  Its still pretty true.  

I have an anvil (naturally) with a hardie and a pritchel hole. Both very well used.

With a bad back sometimes I find the table height a welcome change for light work.

So I thought the ability to utilize any of my fullers, guillotine etc on the bench would be handy at times.

For example, a drilled pritchel hole would allow me to utilize a hold down on drawn out billets for grinding etc.

I prefer holes over anything protruding as I still utilize the table for layout.

I never beat on it and wouldn’t want to do anything that would cause it to crack.

To big to bring anywhere without alot of effort.

jlpservices, can you please explain a little to me what you meant by using shims with the broach?

Thanks

 

[jlpservicesinc]

Use a single sided Broach or corner broach depending on how industrious you want to be.. The shims are used behind the broach to add just a little more to the cut each time.. 

As and example you can look up Key way broach..  Similar in use... 

Match the radius in your anvil hole so all the tools fit as they should.. 

Since you only need a semi accurate sq hole it makes it all the easier..  1/8" drill on each corner or larger if you wanted a larger radius in the corner then a pilot hole through the middle then drill out to 1" if that is the size you want the sq hole to be..  Cast drills really easy and with a simple setup you could get pretty accurate results..  Of course a mag drill would be the bomb digity..  But with simple hand tools it could be done in short order.. 

I've done it accurately with a corner hand chisel vs a broach but control is a little more user dependent then.. 

[Joel OF]

Sorry to do that politician thing of answering a different question to what you've been asked but I can't help thinking there's a way to give you what you want without putting a hole in that table...if you want a hardy hole at a nicer height why not just get a decent size length of box section, (or even round tube for that matter), fabricate up a hardy hole to whatever size you want using mild steel & weld it to the top of the post, and bolt the post to the ground? The it can be place where ever most convenient too.

[Jspool]

Thats ok. Ideas and suggestions are a good thing.  I’m trying to utilize the space I currently have without taking up more floor space.

I don’t really “need” another hardie hole, but the I really didn’t need to put a 4x4 bench in my shop either but it followed me home and my anvil (on wheels) fits under it.  I’m also struggling with how to handle my 18x18x4” swage block without eating up too much space.

[Glenn]

Wheels are great. If the stand needs ground support, than the tongue jacks from a trailer work to raise the stand and move it.

Ever try to sweep the floor with anvils, post vises, swage stands, etc in the way? Roll them off to the side, and sweep the now clear area of the floor. The point is to get what you need into your work area, be able to use it, and then get it back out of the way when your finished. The easier something is to move the more you will like it and the more you will use it.

[VaughnT]

6 hours ago, Jspool said:

A little background.

Its a great table (4x4) that use to be a layout table sometime in its past.  Its still pretty true.  

I have an anvil (naturally) with a hardie and a pritchel hole. Both very well used.

With a bad back sometimes I find the table height a welcome change for light work.

So I thought the ability to utilize any of my fullers, guillotine etc on the bench would be handy at times.

For example, a drilled pritchel hole would allow me to utilize a hold down on drawn out billets for grinding etc.

I prefer holes over anything protruding as I still utilize the table for layout.

I never beat on it and wouldn’t want to do anything that would cause it to crack.

To big to bring anywhere without alot of effort.

jlpservices, can you please explain a little to me what you meant by using shims with the broach?

Thanks

 

I have a bad back, too.  If yours gets to hurting when you're at the anvil, your anvil is too low.  Despite the common notion of the anvil coming up to your knuckles, that's a bit low for some folks.  I put mine about where my wrist is, and I don't have to stoop one bit.... and my back doesn't hurt any more than normal after a day of forging.

A table makes a lousy anvil.  My main bench has a 1.25" solid steel top, but doesn't perform nearly as well as my 300# anvil even though it weighs at least triple what the anvil does.  The reason is simply the amount of mass under where the hammer strikes.

Those old cast iron layout tables are worth a pretty penny.  Even if it's worn a bit, it can usually still be brought back to life by someone that knows what they're doing.  Try pricing a new one and you'll see why the old ones are so well cared for!

I'd be way more inclined to sell that table and buy the materials to make a bigger table more suited to doing non-precision fab/layout work.

Also, once you've drilled through the cast iron, you're upsetting its structural integrity.  That hardy hole might serve as a stress focus and any light hammering on the table could lead to cracking.  Not only will the hole destroy the value of the table for what it was designed for, but you're risking really damaging it if the hardy hole decides to send a crack across the whole thing.

I'm with the others that caution against the notion.  You can raise your anvil another inch or two if you want to alleviate back pain while working at it, or you can make a portable hole that attaches to the leg of the table, etc.  Lots of ways to go that I think would be better ways to go.

[Exo313]

I don't know a lot about cast iron, but don't they make tables full of square holes? 

Honestly curious, is there a strength difference in holes-as-cast versus holes added later?

 

[jlpservicesinc]

1 hour ago, Exo313 said:

Honestly curious, is there a strength difference in holes-as-cast versus holes added later?

Yes there is a difference..  The stresses in the casting are routed in the pattern of the cooling metal..  A flat sheet will have much more tension and compression locked into the plate without a lot of support from the surrounding area.. So if you cut into it.. That part of the plate that was stabilizing the area around it, those stresses are released and next thing you know there is a crack that propagates.. 

On a layout table like a larger Acorn or such those stresses are taken into consideration and some of those tables are stress relieved.. 

 

[Exo313]

That makes a lot of sense, thanks. 

[jlpservicesinc]

You betcha..  

[Frosty]

7 hours ago, Glenn said:

Wheels are great. If the stand needs ground support, than the tongue jacks from a trailer work to raise the stand and move it.

Uh . . . Glenn, it's hard because you have a dirt floor don't you? 

On the serious side, keeping your equipment and tools mobile has serious advantages beyond being able to clean the floor. Different projects sometimes want a different shop arrangement.

Frosty The Lucky.