Hare and Forbes woodturning tools

[Tiger]

<table id="HB_Mail_Container" unselectable="on" border="0" cellpadding="0" cellspacing="0" height="100&#37;" width="100%"><tbody><tr width="100%" unselectable="on" height="100%"><td id="HB_Focus_Element" unselectable="off" background="" height="250" valign="top" width="100%">Dear all,
Some time ago, I posted a thread regarding H and F tools that I had bought when I got my lathe. In particular, that none of the gouges held their edge for very long. The same thing has happened to the skew chisel in that set. What happens with these tools is that they start off okay and behave like HSS tools (which they reputedly are because they are stamped HSS<v:shapetype id="_x0000_t75" stroked="f" filled="f" path="m@4@5l@4@11@9@11@9@5xe" o=""><v></v><o:lock aspectratio="t" v:ext="edit"></o:lock></v:shapetype><v:shape id="_x0000_i1025" style=" 15pt; 15pt;" alt="" type="#_x0000_t75"><v:imagedata o:href="http://www.woodworkforums.ubeaut.com.au/images/smilies/no.gif" src="file:///C:%5CWINNT%5CTEMP%5Cmsohtml1%5C01%5Cclip_image001.gif"></v:imagedata></v:shape> but once you use go past 1 inch of the tool it behaves like a carbon steel tool that simply won't hold an edge, all you get is a jagged burr which as soon as it hits spinning wood bends over. I took some of these tools over to the local woodturning club who told me what they think has happened is that they are made like drills ie only the top part of the tool has decent steel, the rest is crap. Anyone else heard that theory? The only other possibility is that I have ruined the temper of these tools but I would expect that only to have happened at the tip and when you grind well past that then the steel would be ok. I have bought Hamlet and Sorby tools since and they behave like HSS tools all the time.
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[Skew ChiDAMN!!]

I can't say that I've ever heard of this before but, frankly, it doesn't surprise me. If the Hamlet & Sorby tools are keeping their edge, I'd say that eliminates your sharpening technique as the cause.

I thought the H&F tools were CS, but having never bought a set I'm not sure just where I got that impression. :shrug:

[hughie]

Tiger,
Its highly unlikely you have HSS tools. One of the features of HSS steel is that it maintains its hardness at high temps ie red hot.

So most likely you have carbon steel that has only been hardened at the tip or a small portion of the working end and no doubt they are of Chinese origin. H&F sell both Chinese and P&N tools P&N are locally made...maybe still, anyway they are HSS and perform well.

Seeing that your tools are just about stuffed now consider trying this. Get a heating torch...lpg, oxy etc and about a gallon or about 5 litres of oil sump, oil will do for this.
Heat the tip up, when cherry red dip it vertically into the oil, straight down and then gently swirl it around for a couple of minutes.

Then check with a file, if its carbon steel you should get a marked improvement in the hardness ie the file should skid across the surface.
If you harden more than about 20-25 mm [3/4-1"] at a time you will have to look at tempering the hardened area. This does involve a bit more skill and experience, maybe stick with the shorter amount

If hard then gently regrind with plenty of water around to keep the chisel cool as you grind it. Then your back in business, reharden etc when you have ground off the hardened portion.

If they wont harden, chuck em!

[Mulgabill]

"So most likely you have carbon steel that has only been hardened at the tip or a small portion of the working end and no doubt they are of Chinese origin."

Sorry Tiger, what hughie said! I have heard of this before especially with low-end tools.
As the sayings goes, "You get what you pay for" & "Quality cost a little more".

[Fireman sam]

Hss tools have differtent sparks on the grinder then carbon steel :? :?
Andrew

[Tiger]

<TABLE id=HB_Mail_Container height="100%" cellSpacing=0 cellPadding=0 width="100%" border=0 UNSELECTABLE="on"><TBODY><TR height="100%" width="100%" UNSELECTABLE="on"><TD id=HB_Focus_Element vAlign=top width="100%" background="" height=250 UNSELECTABLE="off">Thanks for the replies. The sparks seem to behave like HSS which all makes the issue very confusing but I have no doubt that most of the tool is some type of high carbon steel.

Hughie, your idea is worth a shot, I was hoping someone would make a suggestion that would at least allow me to salvage something from this set, so thank you. I guess it has to be oil and not water that the tool must be quenched in.

They are not P & N. It's that standard set that they throw in when you buy one of their lathes to make you feel that you've made a good buy.
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[Skew ChiDAMN!!]

Ahhh... a "sharpening practice" set.

As with any other steel, HSS has it's good and not so good blends... eg. I'm not overly fond of new Sorby tools 'cos they seem to need way too many trips back to the grinder during a job. Even though Sorby has a rep for good quality. :shrug:

But, given that your tips lasted well at first, I suspect Hughie is spot on. Retempering's worth a shot, of course, but although my original cheap'n'nasty "chaiwanese CS set" was put aside as/when I replaced each tool with better quality ones, I still use the individual tools for experimenting with new grinds or modifying to make "specialist" tools. (Pauses to take breath!) eg. the flat scraper became a ring tool.

So I'm sure you'll find some use for 'em in future, even if it's not something that's readily apparent to you now. :wink:


Sparks? Not the best way of ID'ing steel... but, in general, grinding CS gives showers of very bright sparks, while HSS has less and duller. I have had good CS tools that only give few reddish sparks and cheap HSS that grind with showers of fireworks. So I'd say that the amount of sparks is probably more useful as a hint to hardness/quality than to actual type of steel. (Now, stand back and watch me get shouted down over that statement. :rolleyes::D)

[hughie]

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Hughie, your idea is worth a shot, I was hoping someone would make a suggestion that would at least allow me to salvage something from this set, so thank you. I guess it has to be oil and not water that the tool must be quenched in.


Oil is the most common medium for heat treating. There are only a few steels that require any else, some very high tech and use air quenching etc. With water the most common is silver steel. You can try water the danger is it may cool the steel too fast and it may shatter. Go for the oil first then try water if it fails.

If the oil fails at cherry red try going up to a higher temp ie bright red as it pales out toward white hot. Do this slowly as you will nearing the upper critical temperature, going beyond this will totally stuff it...but then they are not much use to you in their present condition

If they are poor grade HSS as Skews suggests then it will far more complex to harden. Temps are much higher and far more critical, plus the added factor that most HSS are triple tempered.
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[tashammer]

a million years ago, i was given a set of Sorby and other tools that had been in a fire. i took them to the old railway workshops and had them re-tempered and they are still ok some 30 years later.

Perhaps you have a spring works nearby who have a tempering furnace and someone who knows how to use it? If you do, best to get a price first as it might come as a shock (i can't remember how much i paid but i think i thought that i did save money on a new set.