Hardening Steel

[rfcbuf]

I am planning to make some small screwdrivers for my possibles bag using some steel rods purchased in a hardeware store. After forming to rods to shape, how do I harden the screw driver ends. I have a bernzamatic torch, propane and mac gas cylinders, and some casenite. Is casenite suitable for hardening the rods (how do I use casenite for best results) or should I use another method for hardening? Suggestions would be appreciated.

 

[robinghewitt]

For a screwdriver you really need to start with carbon steel which will harden with a bit of heating and quenching.

Case hardening is usually done to resist wear rather than make things tough

 

[Legionair]

It might be mild steel if it came from the hardware store. If it says mild or weldable on the tag, I don't think it's suitable for screwdrivers (least it wasn't when I tried it).

Maybe Casenite would work.... Don't know.

As Squire Robin said, you might want to start with carbon steel... you'll have better luck.

Legion

 

[Vaino]

The rods from the hardware store are probably low carbon cold rolled steel but one never knows for sure. "Kasenit" will only surface harden the steel and the "screwdriver tip will deform when firmly tightening a screw. As regards the hardware steel, heat an end up to a bright red color and quench in water and check the hardness w/ a file. I've hardened steel of unknown carbon and alloy content this way. Otherwise buy some oil hardening drill rod, heat to a red color and quench in motor oil. Polish the "screwdriver" and temper to a gray-blue color.....Fred

 

[Bountyhunter]

Check Brownells or MSC and get you some tool steel. That cold rolled wont temper.

 

[LRB]

Most good hardware stores carry what is called "music wire". It comes as large as 1/4", and is high carbon, already hardened and spring tempered, but is workable with a file. You could anneal it, shape it, and re-heat treat, or maybe use it as is.

 

[boar]

My scewdrivers were made from key stock. Dilly

 

[Roy]

I make most of my screw drivers from keystock. I don't really care if the screw driver tip gets buggered up a bit, but hate when my screw heads get trashed :cursing: .

 

[CrackStock]

Guys in this area use old hex keys for stock. They get them from tool kits at flea markets.

I have not done this yet, but have just come across a bunch of old rusty tools courtesy of Katrina, so I will get my chance.

CS

 

[spitfire]

Kasenite is suitable for high carbon steel.You need toolsteel.Allen wrenchs bought from a flea market would make a economical suitable modifiable subsitute. :winking:

 

[Bill Bounds]

A good cheap sourse of spring steel rod is the farm supply store. Hay binders, combines and such machines have spring steel rods that catch the grass and are replaced frequently and they have them with different thickness. You could cut off lengths with cut off saws and grind the ends by dipping the end in water to keep from loosing the hardness. Probally the smallest would be just about 1/4 inch.
Grass edger blades are made from carbon steel.you could anneal them and hacksaw them to size, shape them then re-heat treat them.
Bill

 

Get some O1 steel (oh, not zero). You can get it from Enco in a variety of widths and thicknesses. When it comes to heat treating it's about the most forgiving type available.

 

[LRB]

With one exception Trigger. Most home ovens will not get hot enough for a tool temper. If you get a good hardness in the quench, it needs a temper in the range of 650o, to 700o, or even a bit more to not be a tad brittle for screw drivers. I just remembered though, molten lead would probably do a good enough job with an hour soak time.

 

[spitfire]

Exactly right.I have tempered springs in a cast iron lead pot on the stovetop. :applause:

 

My references say 500 deg F for three hours. Any stove oven can reach this temp. However all admit that the temp controls on ovens are not accurate, so use an oven thermometer. One book, The $50 Knife Shop, by Goddard, recommends a toaster oven.

 

[LRB]

If the 01 has reached full hardness, 500o would be a tad brittle for a screw driver. One might get away with that temp, if the driver is relatively thick, but why chance it? A spring temper would take a lot more punishment without chipping, or breaking. As far as a single three hour temper, most steel benefits with a cool down between temper heats. Three one hour tempers would be the ideal, possibly with a 24 hour wait between the first, and the other two. I would emphasize, possibly.