What did you do in the shop today?

[BillyBones]

Even leaf springs are not always 5160 that is just the most common from my understanding. 

Been working on grinding this big honkin knife i am making. Got all but some small hammer marks out, they will stay for aesthetics. Flat and straight. Started grinding my bevel. Love that layout dye. Smear it on, set my calipers to .850"... easy peasy line to guide my hand. Going to shoot for heat treat this weekend. (dye makes it look Halloween appropriate too)

Also went ahead and grabbed a piece of bronze from work 1 1/4" x 3 3/4" long. Not going to try add a balance but i am going to try and work some bronze into the handle. I was thinking pommel and finger guard. I may try my hand at casting the bronze. Never done more than aluminum and lead but there is always a first time. 

[JHCC]

3 minutes ago, BillyBones said:

Even leaf springs are not always 5160 that is just the most common from my understanding. 

Very true; this is why lists of junkyard steels should be taken as rough guides at best.

[Jobtiel1]

Yeah I'm not sure if it is 5160, but so far it behaves like it. But yeah spring steel hardens fine in sunflower oil. 4140, known, also does. But it is a medium carbon steel more tool oriented.

~Jobtiel

[JHCC]

55 minutes ago, BillyBones said:

Love that layout dye.

Layout dye is awesome. That and Rapid-Tap make life so much easier.

[Glenn]

The list of junk yard steels is very dependent on what year the item was added to the list. To get the 1950 leaf spring you need to find a 1950 car.

[JHCC]

What's 1950 steel? I get that it's a plain carbon steel with 0.5% carbon, but the AISI/SAE chart jumps from 15XX to straight to 23XX with no 19XX in between.

 

[ThomasPowers]

It also depends on where the information came from; I remember one list that had jackhammer bits as S-7, because "Machinery's Handbook" said that S-7 would make great jackhammer bits. However we knew a guy whose career was reforging jackhammer bits and with over a million done he said he had only run into a handful that were not 1050 as 1050  was an OK alloy for jackhammer bits and MUCH MUCH CHEAPER!

The Primary Junkyard Steel rule is: *TEST* BEFORE YOU USE!

[Purple Bullet]

52 minutes ago, BillyBones said:

i am going to try and work some bronze into the handle. I was thinking pommel and finger guard. I may try my hand at casting the bronze.

Have you ever tried brazing?  I find it is easier to cut and bend large brazing rods (or copper wire) into the rough shape I want and braze them together, then grind it down. That's how I made these. I don't know if I showed you the knife I was wearing at Quad State with the copper guard made the same way. I lost that one recently due to a minor motorcycle spill. 

[George N. M.]

Purp, that's kind of an odd blade shape.  Is there a functional purpose or is it just the coolness factor?  Is the front "end" sharpened?

"By hammer and hand all arts do stand."

[Frazer]

25 minutes ago, ThomasPowers said:

However we knew a guy whose career was reforging jackhammer bits

I met a guy like this as well. Granted he didn't claim to have done a million of them... At least not literally. He said that business tapered off over the years as new bits became cheaper than bringing them in to be repaired. Anyway, he said the same thing with respect to the alloy.

[George N. M.]

Actually, I'd say that's a pretty good finish for pre-grinding.  The only thing that I'd do differently is to bring the tip of the handle back on itself to form a blunt end.  That would be the 1st thing I did to the handle after drawing it out.

"By hammer and hand all arts do stand."

[JHCC]

6 minutes ago, Frazer said:

He said that business tapered off over the years as new bits became cheaper than bringing them in to be repaired.

Bad for the sharpeners, good for the blacksmiths looking for cheap tool material!

[ThomasPowers]

I've only sharpened one bit; a friend of the family rented a jackhammer over a holiday weekend  as he wanted to redo his concrete driveway and needed to remove the old one.  Well the bit broke the first day and everything was closed for the holiday; so he thought of me.  I reforged it and did a heat treat as I remember reading about it and told him "No Guarantees".   Worked a treat he said and it went back with the jackhammer on Tuesday morning.

[USANewbie]

George N. M., was your post a reply to mine? If so are you saying i can expect a rough finish and grinding or filing is always necessary?

[Purple Bullet]

1 hour ago, George N. M. said:

Purp, that's kind of an odd blade shape.  Is there a functional purpose or is it just the coolness factor?  Is the front "end" sharpened?

I call that my fantasy naval blade. My daughter in law has a father and step-mother that are very well off - multiple mansion AND yachts, but they like to live on the yacht. She asked for a set of "pirate" blades. I really don't like the glamorization of pirates, but there was a sword on the wall on "Forged in Fire" that had a shape that intrigued me. That was the result.  She gave them last year before Thanksgiving and they used them to carve the turkey. I didn't make a sheath for them, just a board with hooks to hang on the wall. And yes, the front end is sharpened, but not to the razor edge the blades are. 

[Gandalfgreen]

thise blades are excellent looking. everyones work is always amazing jeep on inspiring me I am almost set up.

[George N. M.]

USAN, yes, it was directed to you.  My experience is that you cannot get a perfectly flat blade by forging.  You can get fairly close, particularly if you use a flatter but if you want a smooth surface on a blade you will need to file or grind.  If nothing else, to remove the scale.

Maybe better bladesmiths than I can do better but I have never made a knife that didn't need abrasive treatment in some way. 

"By hammer and hand all arts do stand."

[USANewbie]

Thanks George.

[swedefiddle]

If with this Blade, you should win, Forge it thick, Grind it thin.

I heard this first, from Frank Turley.

Neil

[USANewbie]

swedefiddle,  I've heard that quote before but forgot, thanks for sharing it.

[BillyBones]

11 hours ago, Purple Bullet said:

Have you ever tried brazing?

Oh yes, i have done a lot of brazing. I am actually pretty good at brazing with an oxy acetylene. 

I missed the knife, bites that you lost it. 

[Purple Bullet]

It was my own fault. I'd bought a generic sheath at Quad State (leather work just not my thing) and told myself I'd add a snap strap keeper to it but never did. Then I took an off-road short cut that I've taken dozens of times on my bike, but this time there was some storm debris. Slow-speed tumble, but then I was more concerned with getting my bike back upright.

The worst part is that I neglected to take a picture when the knife was done. I always thought I would add another tweak. Now, like they say "It never happened." Except for the lessons I learned from it.

Anyway, what I was talking about was a technique I learned ages ago in a ship yard. Brass props would come in missing several inches of their edges. We would braze a 1/4" brazing rod to it and heat and bend it to the original size of the missing part of the prop, them cut more brazing rod to fill in the gap inside that shape. We would then braze it all together. Perhaps a better term would be acetylene brass welding because brazing is typically where the brass gets liquid, but the base metal does not. 

If I was set up for brass casting, casting might be easier and quicker, but this method is pretty easy and quick. If you do it before heat treating you can also braze it to the tang which makes the guard very strong and immobile.

[HondoWalker]

Last week a very kind and generous member here sent me some good steel. I forged a piece into a blade. I quenched it and tempered it into some very very hard steel. I tried not to quench the tang but it got hard anyway. Had to use a torch and heat it up enough to where I could drill a hole in it. It's still being worked on. But I noticed something and it's got me curious. On this blade it has cracks on the surface where I had to spread out the steel to make blade, This has happened several times before on other blades I made that got hard. Why does good steel do this? How do I prevent it? 

 

 

[ThomasPowers]

Working too hot, working too cold, too aggressive a quenchant, not normalizing before quenching.  We'd need a lot more info including what alloy you were using.

Your question seems to me to be asking Why does good high carbon steel act like good high carbon steel?  Also why we tell folks that bladesmithing is a harder than hammering mild steel as there are more factors you need to be taking in account at all times. (And why "practicing" on mild steel only helps the hammer control aspects and not how to forge HC steel aspects.)

[Frazer]

Any idea what kind of steel it was? What a your quench medium? If you left deep (sharp) hammer marks those can be sites where cracks can propagate from during the quench. There are quite a few factors.