How hard should an anvil block be?

[Judehey]

My flea market anvil pretty has no good edges, so I made an anvil block by welding square mild steel bar for the hardy hole to a hardened steel bench block I had laying around.   Predictably, the weld failed after a few dozen strikes.  Internet research says I should anneal the hardened steel, weld, then harden again.  I have no idea what kind of steel it is, and I don't have the tools to anneal properly,  but I figure I could at least normalize it. Do I need to try to harden it again after I weld it, or will the normalized steel be adequate?  I don't have experience hardening, and I'm not sure it would fit in my forge.

Thanks

[Irondragon Forge ClayWorks]

I would just use it normalized. When you welded the hardy shank, did you taper the bar to get better penetration of the weld beads. If you can drill the block then forge the bar to fit in the hole and plug weld the top might work. Maybe a picture would help.

[Frosty]

Where and how did you weld the shank to the block? 

It seem intuitively right to weld the shank to the bottom of the tool but that really limits how much weldment is available to hold and it'd directly under the forces of hammer blows. 

Some bottom tools don't undergo a lot of heavy blows so you can put the shank almost anywhere but for the ones that are going to get BEAT upon I weld the shank to a side. This allows the welds to run the full depth of the bottom tool, "anvil block" in your case, plus across the top and bottom. beads cleaned up so as to not take impact energy directly. 

The other advantage of welding the shank to a side is positioning. You can put the working part of the bottom tool over the sweet spot of the anvil or maybe along an edge so you can work over the side, etc.

Bottom tools usually aren't hardened and it won't make a difference, you ARE hitting HOT steel. Yes? In my opinion 4140 makes wonderful bottom tools, it can be hardened in oil and tempered in a toaster oven with little chance of embrittlement. It's also VERY shock resistant so it isn't going to work harden from use making the edges likely to chip. 

I get my larger pieced of 4140 from an oil tool machine shop's drops. Drops are pieces that are too small for their commercial products but are too large to comfortably call scrap. Fab and machine shops are excellent sources of steel in shorter lengths, thickness or maybe odd shapes.

There are some rules for doing this successfully though. #1. Talk to the guys in the yard, NEVER ask the counter folk. Counter folk MUST charge you per cut, even if it's already been cut. Cut charges can be $5-10 per cut. #2 Offer the crew chief or whoever is in charge right then in the yard, to pay the per lb. price. #3 and most important, Stay out of their way, when someone notices you they'll talk when they can and point you to or holler for the guy in charge at the time. Keep your head on a swivel, watch everything the yard is NOT a safe place if it's not your environment.

I also never ask for new stock to be cut for transport, I pick steel up in my pickup and hauling 20' sticks is inconvenient. Remember the guys at the counter MUST charge per cut. Ask the guy loading you if he doesn't ask you first. The yard gang will just whack it on their giant cold saw and load your rig. THEY don't want to pack say 10, 20' sticks of 1/2" square from the racks to your truck That's a lot of weight and a number of trips. Nope, they'd MUCH rather drop your 10 sticks on the cold saw with the yard fork lift, whack them all at once and  load your truck. You DID park where they told you to, next to the saw. Yes?

Get on the yard crew's good side and they'll likely just throw a bunch of drops in your truck and charge you $20. You get home and discover why your truck was squatting on the drive. 

Remember to bring them a box of doughnuts next time you go steel shopping! Keep on the yard guys good side.

Frosty The Lucky.

[caotropheus]

Some pictures can help a lot.

And yes, you can anneal a block of metal of any size in a "at home setting", but that is not a discussion for "Anvils, Swage Blocks, and Mandrels" forum, rather for the "Heat Treating, general discussion" forum. If you open a thread there, I can help you with some suggestions.

 

[FlatLiner]

I made an anvil block out of a piece of fork lift tine just to say I made one. Truthfully I use a drop of S7 or the post anvil I made from two fork lift tines more then the anvil block. If I need "better" edges for something that I am doing. I welded the shank like Frosty explained but I added two to the front that slide outside the anvil to prevent twisting.

[ThomasPowers]

Did you preheat the anvil block before welding?   This is a basic mandatory step to prevent HAZ cracking when welding medium to high carbon steels.  The preheat is in a range of a kitchen oven but is often done in the shop with whatever is available.  As the preheat is *BELOW* the original tempering temperature it will not need rehardening.

[BIGGUNDOCTOR]

Pictures would help too.  Many tool steel are air hardening, so they need to be welded and handled far differently.

[Judehey]

Thanks for all the tips and advice.  I did bevel the bar,  about 1/8"  I admit I knew I should have preheated the block and just plain forgot. I'll try again with a preheat,  if that fails I'll try normalizing and/ or a side weld. I'm a total beginner at this, just more opportunities to learn. 

[FlatLiner]

Pre heating and post heating the block about 400 ° F will help with not getting haz cracking.

[Irondragon Forge ClayWorks]

For beginners reading this the HAZ is the Heat Affected Zone.