Heat Treating

I am in the process of making a wood cutting tool for use on the wood lathe. The metal stock I am using is the handle of a half inch ratchet. After heating and forging one end flat I would like to heat treat that end to be more wear resistant. Is it really as simple as heating the end red hot and cooling in old engine oil? Thanks for your responses. Rod.

I'd say that might depend on the brand of rachet. If it is a cheap chinese one, it probably is no more than hot rolled steel and does not have enough carbon content to harden. A better quality one might. Not all steels can be hardened.I am not a metallurgist by any means. But I have played with blacksmithing some and there is not a set answer for your question. Heat treating ,tempering etc processes are very temperature sensitive,old time blacksmiths had an eye for that,but that is a dying art. Try it you might,get lucky.

(quoted from post at 12:42:39 02/23/14) I am in the process of making a wood cutting tool for use on the wood lathe. The metal stock I am using is the handle of a half inch ratchet. After heating and forging one end flat I would like to heat treat that end to be more wear resistant. Is it really as simple as heating the end red hot and cooling in old engine oil? Thanks for your responses. Rod.

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You'd be better off using an old file to make a wood cutting tool.

Much better and the right kind of steel.

1370rod: as was stated, that's very difficult to answer without knowing what steel you're working with, which is very difficult to tell, even for an experienced metalworker, without doing some experimenting. The most obvious experiment is to try it--if it hardens, then you can harden it that way . If the base stock is common O-1 or similar, then the method you described will work, so you don't have a lot to lose. By far a better method would be to find a different piece of steel with known quantities. What kind of lathe tool are you making? I've made a bunch from old files, leaf springs, concrete nails, car axles, and several other sources of scrap that are much more apt to be types of steel with the proper metallurgical makeup to harden well than a ratchet handle. Again, nothing wrong with doing what you're doing, just be prepared for the possibility it might not harden. Go ahead and try it--heat it to critical temperature (red-hot, and easily determined because a magnet will no longer stick to it), quench immediately in oil (you can use motor oil but I usually use canola as it's less flammable) and see if a file will bite on it. If it just skates over the surface, it hardened properly, if it bites in, it didn't. In any case, when you're done, you're almost certainly going to need to temper it for it to be useful--if left in a straight hardened state it will most likely be too brittle and difficult to sharpen to be useful. Tempering's another kettle of fish, but post back when you get that far and we can take the next step at that point.

I'll go along with TimV but add a little. If you don't get the hardness you need try it again and quench in water. A faster quench will help with lower carbon content.

Tempering will draw back the hardness a little to make it less brittle (like a file). Grind it like you want it then use an acetylene torch to heat the shank well above the cutting edge and watch the color change. When it goes from straw color to blue under the flame let the straw color advance till it gets to the cutting edge then quench it in oil and keep it moving. I've done this making cold chisels and punches.

No guarantee, but a long time ago I made a chisel out a hex material but I don't know what metal it was.

The cutting end was heated until a magnet would NOT stick to it and it was quenched in water. It is now as hard as it can be.

Next we ran to the grinder to make a bright spot on the side of the edge. Then we put it in the forge handle end first (so that end would be softer) and when the bright ground spot turned a straw color it was quenched. Different colors are different hardness.

Next we grabbed some scrape and set the corner of the chisel on it and whacked it because that would be part of the grading test.

I don't know if this works on ratchet handles but this my 2 cents worth.

RT

Thanks everyone for your input, you have been very helpful. You were right I could not get that handle hard,, ended up using a spring shank from a cultivator. That did harden properly and a file skates over it. I was able to sharpen it with a stone so I tried it out. Works good but does not hold a sharp edge very long on the projects I am doing which requires cutting end grain of walnut. For a comparison I sharpened the end of a US made Nicholson file and that held a sharp edge for about the same length of time. Some of you mentioned tempering the cutting edge. Would that make it more wear resistant do you think, or should I leave well enough alone? Thanks again, Rod.

1370rod: it's doubtful if tempering would improve wear resistance--typically it's done to make steel less brittle, more flexible, and easier to sharpen. However, it's possible that the wear you're seeing is a result of the edge breaking off. Try looking closely at the dull edge--does it appear jagged and broken, or rounded over? If broken, you could try tempering it and seeing if it improves things. Walnut isn't a particularly hard wood to work, and your edge SHOULD hold up reasonably well, even in end grain. Post a picture of your tool, and maybe we can offer other suggestions.

I will get a magnifying glass and examine the edge closer, Rod.

The sharpened ende is tipped down with know sign of chipping. I am using this tool to shape round ruff cut blocks of walnut to finish in to bowls. Normally a gouge would be used for this operation. My gouge is not large enough to safely control when rounding those large awkward blocks. Ithis scraper I built is three ft long, and solid, easy to control and does a good job. The cutting end is shaped like a thumb and about that size. Something about that end grain wiping down on the cutting edge tips it. Shaping without going through end grain is a breeze. Even with frequent stops to sharpen it is faster and safer than my gouge. Rod.

1370rod: I figured it was for bowl turning--I made my brother-in-law a few different bowl turning tools a few years back when he was doing a lot of it. Bunch of Youtube stuff showing homemade turning tools for that application as well if you're interested. The two most useful things I did for him were a large, steady tool rest that would pivot inside the bowl so he could get closer to the work with less overhang of the tool, then made longer-handled versions of his scrapers using interchangeable tool bits so that you could control them by tucking them between your arm and side. Really made the shavings fly when properly tuned up, and MUCH less dangerous to run as there's a lot less leverage on the lathe end and a lot more on your end where you want it.

Thanks for all the advice. I will check out YouTube also, never thought of that, Rod.

Here's one to start the wheels turning, or is that the bowl turning?? Harry's an English gent, and his channel has quite an eclectic mix of hand crafts on it-he's best known for making Windsor chairs, but does a bunch of other interesting stuff from leather work to stained glass repair as well, and, of course, does a lot of turning to make chair parts on a pole lathe he built himself. His reference to "silver steel" is what we'd call drill rod, I believe, which is what I used for the shanks of several of my tools.
making bowl turning hooks.

Any time you heat treat something, tempering is mandatory, or else you are playing with something very dangerous, highly alloyed tool steels will actually break into many pieces if not tempered soon enough after quenching. Quenching should only be done down to 150 degrees and followed by immediate tempering. For garden variety steels, throw it in your oven at 350 degrees for at least 2 hours, that will leave the tool at maximum hardness and remove the danger of shattering, otherwise just dropping it on the floor will end in a result like dropping a crystal vase on the floor.

get you some Kasenit or cherry red and case harden it