I was going to link a couple then remembered Graingers is a commercial site. Yeah, there's probably one cup wheel for steel for every 30 concrete stone cups. It always surprises me and this wasn't the first time I've looked. There's a local commercial type hardware store AIH that keeps different sizes and grits of  steel grinding disks on the shelf so I'm probably a poor advisor for finding the things. Heck they keep a decent selection of 2" x 72" grinding belts in stock. 

Uh, you HAVE checked with the closest industrial type hardware store haven't you?

Frosty The Lucky.

Nope.  I was just gathering information at that stage.

Ultimately I went with the router/carbide bit plan.   I can't say I recommend it, but it did work - although I did pretty much destroy the carbide bit by the time I got the second surface finished.

Now it's on to designing, fabricating, and installing the die holder for the anvil.

If you weren't bleeding when you finished I call it a win win. I didn't expect one carbide to do both ends, you DO know how to be easy on a tool! Well done.

Frosty The Lucky.

It was a slow process.  It took a while to get the block leveled satisfactorily and then install and level the rails.  Of course I had to build the sled for the router too. Working a surface more than 5 inches square a quarter inch at a time is a little tedious as well.  Still, it's far better than I could have eyeballed, and I'm comfortable it's good enough for dies on the top and welding to steel plate on the bottom.

The bleeding was minor.  I got a couple steel splinters, but that seems almost inevitable for that kind of work.  The blood could be measured in droplets, so I'll consider it a win as well.

Yeah, steel splinters hardly count, unless they go all the way through, of course.

1/4" x 5" is only 20 passes, how much depth were you taking? Uh, you didn't make the frame and sled FIRST? 

Heh, heh, heh, you got it done safely, exactly how isn't an issue. You done good.

Frosty The Lucky.

There was a bit of a learning curve to the whole thing, and it was further from "square and flat" than I thought.  I had to adjust the depth at least 3 times on each side. The bit wasn't touching in some places, but was removing around 1/16" (guesstimated) in other spots.   I should have said the bit was 1/4" wide and each pass was about 1/2 of the bit width, so double the passes where there was material to remove.

Like I said, I can't really recommend it, but I know I can make it work when I need to.

Of course it only touched the high spots or you wouldn't need to square it off. 

1/16" is a LOT deeper cut than I'd recommend, just skimming is like taking off a coat of paint.

I understood you meant 1/4" passes being 1/2 the bit's width. Trying to take more than 1/2" really pulls the bit sideways, if out of the cut it's out, if towards the cut it chatters. 

It's not my first choice either but I have a good cut off bandsaw and keep new blades in the locker. However I spent 20 years of my drilling career improvising ways to repair broken drill rigs miles off the road and believe me track mounted drill rigs break a lot. Happily well designed ones break where they're easy to get too to repair. Idiots reinforce the built in failure points and regret it when they have to crawl inside the works to reach the break. 

Having to pack a right angle drive ANY distance will learn you quick! Yeah, that broke because one of the new guys reinforced the spot on the extension bar where it kept breaking. Of course HE wasn't there to help carry it but there were 3 of us had a word or two. I'd told him not to and why but . . .Nevermind it wasn't a happy story. Except maybe making the front office guys have the replacement drive air dropped on a sand bar about 100yds from the drill. We STILL had to carry that thing back and hand lift it into position. Nothing is light on a soils exploration drill!

Frosty The Lucky.

Good to hear you tried it. Now you have an idea to its limits and strengths. My setup for half log treads was the same, but because it was wood, I could remove more material. Still on a 16" log surface, it was, like your deal, lots of passes. 

I'd still recommend a large 9" or larger side grinder as the tool of choice. Theres a lot of torque and that works in your favor for keeping your surface in plane. You can easily feel the highs and its not too hard to learn to just kiss the surface and feel more and more contact as you progress down into your work. Best of all, the large size covers your whole width, so not so tedious as mucho multi passes with a router.

Congrats anyway on a job well done!