Score on the way to in-laws

[TrippSixx]

It's been raining where I am for the last three day s and having worked at AutoZone in the past I know on rainy days is when people replace there blades. So I pull imto, or behind AutoZone and hit the dumpster. I managed to get over 100 wiper blades metals in different lengths and widths. Now tomorrow after Lowes opens back up I will be going to pick up some files, a dremel, sandpaper of varying grits and get to making some picks and tension tools of my own. I'm excited.

[GWiens2001]

We want to see pictures of your work when you are done.

Gordon

[TrippSixx]

Even though it will be my first attempt at making my own picks. I will definitely show what I did in hopes of getting feedback.

[jimu57]

I found different width and thickness at Autozone. I made some tension wrenches but never tried picks. Seems like all you could makeep would be a short hook. Can you actual make others?

[GWiens2001]

Have made short hooks, medium hooks, deep hooks, reach picks, half diamonds and Bogota picks from wiper inserts. Just don't let the metal get hot enough to turn red, or the temper is gone. Also, if it bends easily (and holds the bend when released), then don't waste your time. You need the good spring steel.

Gordon

[TrippSixx]

Went to Lowes today to check out some files. Would the carbon or the diamond files work better getting the finishing touches on them after I dremel them first? I plan to dremel the most meat off then finish with files. But while grinding I plan to keep some cold water close by to keep the metal cool. Like grind for a bit. The quench it in cold water. Grind and repeat. To not lose the temper in the metal. Just my first attempt at doing this but will be a learning experience.

[munron]

Sounds like we might be in the same boat here. I've been manufacturing picks out of old hack saw blades and torsion tools out of allen wrenches using my bench grinder and a couple of files. So far I've managed to pick a few simple locks with my creations, but it definitely a work in progress. It's a very satisfying feeling when I succeed though.

[kwoswalt99-]

Just don't let the metal get hot enough to turn red, or the temper is gone.

It doesn't even need to be that hot. It only needs to be hot enough to make the oxidation colors.

[Rakka]

On the Temper....... isnt it to soften metal to work with you heat red hot then let slow cool.....and then to " re-temp it " after working it you red hot it again but then water dip it for fast cool down to reharden it?

Ive heard this alot from a couple Old timer blacksmiths....never actually researched it myself, but I have always done metal work this way with excellent results. But again...I personally do not know forsure.

But, if anyone does know let meknow

[Joshua904]

Quenching metal will harden in. Think blade edge retention.
But it makes it brittle, and will snap easily.
Normalizing the metal would be the next step. That's when you slowly heat it up and allow it to slowly cool to room temp. It's typically done in an oven and done more than once.
This will cause it to soften enough that it doesn't snap, but bend some.
Tempering just means changing the metal through temperature.

You'd want a pick to be hard enough it doesn't just bend every time you apply pressure, but certainly wouldn't want a pick that snapped off in locks with ease.

[Jacob Morgan]

Sorry for the long post, but I grew up around this sort of thing.

Heating to red hot then setting it aside to cool slowly should anneal steel, i.e., take it to dead soft if it is not already there.

In general, high carbon steel can be made hard (and brittle) by heating it red hot then quenching it. Every metal worker has a secret for how to quench, I've known people to use salt water, transmission oil, engine oil, olive oil, lard, vegetables (no kidding), and just plain water. Rapid quenching can lead to warpage.

After the metal is hardened one needs to back off the hardness (tempered) to reduce how brittle the steel is. One way is to polish a bit of the metal then once it turns a certain color (yellow, blue, or brown depending on the goal) one then sets it aside and lets it cool. Or one can pop it into the oven in one's kitchen at 450 or 500 or so for a couple of hours. At that point hopefully the hardness and toughness is just what you need.

In reality it is hit and miss if one does not know what kind of steel they are dealing with. Knowing the steel one has, one can look for suggested hear treatments to get what they want. Gunsmiths do a lot of heat treating, so do bladesmiths. Some have dedicated heat treat ovens, those on a budget can use temperature specific lacquer, or use tricks like checking some steels for a lack of magnatism that signals certain temperatures.

The first step is to see if it is high carbon steel at all, otherwise this is all a moot point. Draging a file across it to how much of a bite it takes is one check. A better one is to learn to read the sparks that come off your grinder. Individual sparks that come out in a straight line means low or no carbon. The more complex each individual spark (if the spark splits or looks like a firework) then it has more carbon.

There is a way to make low carbon steel hard, even in a home shop, but easier to get good steel in the first place.

When I've worked with metal that was already as hard and tough as I liked, especially thin stuff like hacksaw or bandsaw blades, I've tried to keep it that way. I don't wear gloves when grinding and if the work piece is hot enough to notice I dunk it in water. Or dunk it every couple of swipes across the grinder. You can cool it in water (without hardening it even more by accident) if it never heats up much in the first place. Again, home heat treatment of mystery metal is hit and miss, so why go through the process at all?

If you over do it and the metal starts turning colors (it starts with blue), then not all is lost. Carefully grind away that discolored metal, works so long as the discolored metal was not part of the final pick. I'm not sure that a soft pick would be the end of the world anyway, brass is not going to wear it down quickly. A bigger problem might be breaking a brittle pick (or wrench) that was heat treated but never tempered.

[Joshua904]

That's a way better explanation. Thanks.
I've had bad luck using hack saw blades for picks, but a cheap alternative is 4mm key stock. Its sized right for bigger tension wrenches, if you thin it out. It's typically lower carbon steel so it won't be too hard and snap. Also it comes in lengths about a foot long for a dollar or two, so you can make a few picks/wrenches.

[Jacob Morgan]

One clarification: when tempering you polish up a spot then reheat the item until the given color shows up in that polished spot, then it is set aside to cool. I had forgot to mention the reheating part, although most people would figure that out.

In Weygers's Complete Modern Blacksmith he lists peacock for thin delicate tools (640 F), bronze for wood-carving gouges (520 F), and straw for center punches (440 F). He recomends oil or lard for very thin work pieces for the hardening quench. The lower the tempering temperature the harder (and more brittle) the item.

[kwoswalt99-]

There is a way to make low carbon steel hard, even in a home shop, but easier to get good steel in the first place.

Outside of adding more carbon to the steel, I have no found a way that yeilds adequate results for my uses.

Spark tests are my favorite way to determine the type of steel. They have some convenient charts to even identify very specific "alloy" steels.

[Jacob Morgan]

The way to harden (the skin at least) of low carbon steel is to case-harden it by adding carbon to it. In industry there are carborizing furnaces that do that. In theory, playing a reducing oxy-acet flame on steel would do the same thing. For a home shop one can use case-hardening compound. Heat the item to cherry red then plunge it into the compound. The carbon from the compound moves into the steel. It only goes one or two dozen thousandths deep, so it hardens the skin but leaves the core soft--ideally it makes a hard surface and a tough (non-brittle) core.

If one heat treated a carbon steel pad lock shackle to, for example, a Rockwell C hardness of 60 or so it would be completely safe from a hack saw blade but an 8 year old could shatter it with a claw hammer. For that reason some padlock shackles are case hardened for saw and impact resistance, especially if they are made of cheap steel.

Cherry Red http://www.midwayusa.com/product/119479/cherry-red-surface-hardening-compound-1-lbis one case hardening compound you can buy. Kasenite is what I have used before, but I don't think it is sold anymore. Some gunsmiths who refinish antique guns with case hardened parts make their own case hardening compounds from bone meal, burnt leather, and charcoal. After case hardening, do not try to heat treat or temper the metal.