does a letter opener qualify?

[bluerooster]

I am a very noob to forging.  I've only actually made one useful item, tongs, which I'd not set out to make. I was just heating and hammering on a length of rebar, simply to learn how to swing a hammer, not intending to make anything at all, but just to move hot metal. That rebar turned into ugly but functional tongs. (even a blind dog can find a bone once in a while) Well, next time i fired the forge, I decided to see how a bearing race would behave. It was an outer race for a large ball bearing. I cut it in half, and tossed it in the fire.  I set about the task of flattening it out, which, if you can imagine what a ball bearing race looks like,  made a nice curve. As I flattened the thick part, It in effect drew it out on that side, and made a nice curve.  Many heats, and much hammering, I ended up with a straight (ish) piece of steel about 8" long, and mabe 3/16" thick.  I didn't want it to be that long, or that thin, so I folded it in half, and re-heated it, sprinkled som borax on it, and stuck it back in the fire. Durn near burned it, getting it hot, brought it out and gave it a few licks, then re-heat, and a few licks on the other end. disgusted with it, I threw it back in the dying forge, and walked away.  I was out of charcoal anyway.   After a week or so, I  set about seeing what I'd done to it. It was a bit rough around the edges, with de-lamination, but appeared to be stuck together in the middle. So, I heated it up, and drew it out to about 6" long x about an inch wide. Got it to a good red temperature, fully soaked, and dunked it into a bucket of water.  I figure that would make it brittle. It sure did!  I clamped it in the vise and snapped it off about mid way.  Looking at the "end grain" (carpenter here) I could see what had stuck, and what had not.  I took one half, and welded a handle on it, By setting up my forge better, better layer of charcoal, less air, and much drawing and folding, I figured out what I was doing, and where I was going wrong.  I still have a long way to go.  I drew, and folded this chunk, about 10 times, before I ran out of charcoal again.  It was a week before I got anymore charcoal, and work, and life in general.  I decided one day that I would draw this chunk out, and see what it wants to become.  With my old cross peen body hammer, I managed to draw, and shape something that looked kinda like a blade. But not big enough for anything but a filet knife, so I figured on mabe something that favored a miniature sword.  I drew it on out, and gave the shape of a double edge blade, with tang.   Today, I filed it to better shape, and decided to harden it. Interesting thing, hardening of steel. I had no "quench oil"  But I had a half quart of ATF so thats what I used. I clamped the tang in vicegrips with the blade pointing upward at about 40* angle, with vicegrips laying on the table.  Played the torch over it from bottom to top untill it turned a cherry red color, and held it there for a bit, to ensure that it was thoroughly soaked, then into the oil.  I pulled it from the oil, and hit it with a file, which dug right in.  Hmmm, sez I. Mabe I didn't get it hot enough. Oh well, it's just a letter opener, no need to be hard, or sharp, for that matter.  I wiped the oil off, and drug it accross a stone to remove the worst of the file marks. Well, I noticed a spot that could use another lick with the file, so I went to file it. Huh. It's hard, the file just skates. Interesting. Well, curiosity got the better of me, I clamped it in the vice, and snapped it off. Woo-Hoo!  Hard, and brittle, just what I wanted.  Tempering would have come later. 

 Tongs,  After the snap, and end grain after the snap.

[ThomasPowers]

Beginning knife forgers often have a substantial decarb layer on the outside of their blades that doesn't harden like the center of the blade does.

[MCalvert]

Is this due to excessive heats, excessive scale, or too much heat?

[ThomasPowers]

Well, yes; but in general: too much time hot and too oxidizing a fire   Both cause excessive scale.  Excessive heat usually burns the steel which trashes it---also a common beginner mistake---particularly when they put the workpiece in the fire at a steep angle instead of horizontally through the neutral/reducing part of the fire.

This is why some experience forging really helps, you can swing the hammer fast and accomplish the task in fewer heats and you are a better judge of temperatures---knife steels have more restrictive forging ranges than mild. Too hot or too cold can ruin your workpiece.

[Matt Scanlan]

The magnet test is also a good way to prevent overheating most oil quench steels when it comes time to heat treat. Once the steel begins to glow a dull red start checking it with a magnet. If the magnet doesn't stick its good to go. Not high tech in any but it has rarely let me down so far with 1080  

 Ive only been doing this for 8 years but I remember thinking I had to get the steel up to a bright yellow then quench it, ruined alot of decent blades that way. 

 

[bluerooster]

Yes, when the steel becomes non-magnetic the quench temp has been achieved.  Also, be careful about the heat being even throughout the blade.   The blade that I snapped off, I heated with the torch, with the blade vertical, tang down, started heating near the tang, and worked up to the thinner parts, making sure the tang didn't get hot, but also making sure the thinner parts didn't get hotter than the thicker parts.   I don't have a grinder per-se, so I filed the profile, prior to heat treat. Then all I hadda do is work it by hand on a stone.