Cutter thingy

[kayzed1]

Hi all, i mate asked if i could make him a cutter ( for wood ) He used to make cart wheels with his Great grand Dad as a lad, he now wants to start again. He saw on the tube a guy who had made a cutter for the end spigot ( if that is what you call it ) the end bit of the spoke that fits into the wheel ( wooden tyre ) before the steel tyre is fitted. It has to cut a 1" spigot so because of the size of the spokes this has to be three inches across, 1" hole down the middle and two X 1" blades one each side of the bore. So i had a lump of round bar 3" across...chopped with the saw and that took 48mins so i should have then had an idea this was going to go slowly. Very carefully chucked it in the 4jaw ( Myford s7 ) and very carefully cleaned up both ends....Re chucked and revolving centre fitted i started to cut slowly ....What is the steel! i was told it was a JCB ram,
i have used them before and they cut nicely after you get through the hard outer case. 4 inserts latter i rang the guy who gave me the steel bar.
Oh! sorry he says i forgot to tell you this bar was from a lift shaft, it was the pin the lift cable drum runs on Once i got 8mm into it it cuts very well...
Lyn.   

[Biggles]

Hi Lyn, the metal sounds like something that is either case hardened or something like EN16T. 16t is a tool steel which is hardened for some of the thickness. If the item was designed to break, it’s probably case hardened for wear resistance. 

[sparky961]

I've had some luck with "backyard annealing" in my propane aluminum furnace/foundry.  Just stick the piece in there and get it as hot as my furnace goes (about where Brass melts).  Then turn it off and seal it up the best I can and leave it until the next day.  You could also bury it in sand, or anything else that will insulate.

I've thought about trying to toss a big chunk of hardened steel into the wood stove with a nice hot fire going (the wife would love the house temperature while doing that).  I figure the inevitable cool down overnight would anneal it quite nicely as long as the fire got it hot enough in the first place.

I've done this with pieces a file wouldn't even touch, and they saw and machine absolutely beautifully afterward.  I'm sure I could even re-harden some of them if that's what I wanted to do.

[kayzed1]

Thanks for the info, looks like i will have to find a furnace then, i can get another bar this one is 4"X 56".
It would be a shame to let it go to scrap when it is free.
Lyn.

[chipenter]

I got some hardend pins from a fork lift 2"*8" , droped them in the bonfire when we were trimming some trees , they were still hot 2 days later rusty but annealed .

[Joules]

Attack the outer with an angle grinder then cut up with bandsaw if you have one.  Manageable chunks can go in the wood stove.   No, I wouldn't turn down material like that either.

[sparky961]

I've got some irons in the fire tonight... lol, literally.

I grabbed two of the hardest pieces of steel I could find in my box of odds and ends and when I had a nice roaring fire going I tossed them in right where it was hottest.  I let the fire roar about as hot as I felt safe with for maybe 15-20 minutes and the pieces were glowing maybe light orange with some orange-yellow at the corners.

I have a feeling they'll be nice and soft with the slow cool down overnight, but we'll see.  Pictures to follow.

One thing I did wonder about is carbon content.  I guess in most cases we aren't planning to re-harden these pieces we come across, but would anyone care to chime in on the likely chemical changes in the steel?  To what depth might it likely be affected, if at all?

[sparky961]

The pieces were retrieved from the fire yesterday morning after spending maybe 10-12 hours in the fire overnight.  They were air cooled the rest of the way on a fire brick near the stove.

The pictures that follow should tell the story pretty well, but if you have any other questions I can answer I'll be happy to try.

And just as a reminder, prior to annealing these pieces were so hard I was afraid of damaging my file on them!

[kayzed1]

Thank you Sparky, i will give it a try when next i have a big fire going....me thinks this week i may have a load of old wood to burn
Lyn.

[jcs0001]

As far as annealing I've had decent luck also.  I needed a big ball bearing (about 1 in. diameter) for a Howard Hall grinder rest.  It needed annealing as I had to drill and tap a hole in it:



I used two of the usual small propane torches, heated it as hot as I could get it (glowing red) and then submerged it in a can of sand till it was cold.  Surprisingly it worked very well.

Very recently a friend loaned me a small forge so heating things up now will be much easier.  It gets very hot very quickly.



John.

[jcs0001]

Sparky - should have mentioned that your experiment with the fire is a good one.  I will keep it in mind for larger pieces.  Might as well get some extra use out of our firebox in the winter.

John.