Brazing TC to spring steel

I have a post hole digger with some blunt TC tips, brazed to spring steel tangs.
I may have trouble replacing these as the machine is pretty old. I
have contacted the company that bought out the company that...like I said it's old. Their setups have changed.
Similar ones are also rather expensive. If I buy them I have to rebuild the whole head on the auger, and it becomes a questionable exercise.
So. It occurred to me that I could delay the inevitable by detaching the TC tips and turning them around. They are flat plates maybe 3 mm thick and 16mm x 16mm (1/8 * 5/8 *5/8") square. Of course the back sides will have sharp edges and corners.
BUT. How much will the brazing affect the temper of the spring steel?     - I do not know if these things are temepered, even, but I want to minimise the damage I do.     - if they are tempered, obviously the damage from heating will be worse near the root of the tangs, not the tips. Any ideas on how to heat the tips to brazing temps, but keep the rest of the tang cool.
The tangs are 16 mm (5/8") round stock, 90mm (3 1/2") long.
I gather I don't have to worry too much about the tungsten.
Any help appreciated.
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vaguely proposed a theory ......and in reply I say!: remove ns from my header address to reply via email
hmmm. I appear to have lost all appeal here.
Having supported the group recently, I asked a question and was givne a lot of judgmental, irrelevant crap by way of reply. I reacted badly Now I get no reply. I see many other posts after mine replied to, many of them OT.
With a (no doubt mutually uncaring) whimper we watch me depart in to the mire.
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Old Nick wrote:

I think you have simply lost patience. Your first post showed up here late Tuesday, This is Thursday morning.
Ted
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On Thu, 27 May 2004 19:01:19 GMT, Ted Edwards

Tell 'im it was the "snotty" sig he's using.
-- Life's a Frisbee: When you die, your soul goes up on the roof. ---- http://diversify.com Comprehensive Website Development
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Old Nick wrote:

Hi Nick First are you sure it is carbide ? Seems to me that would not stand up to rocks very well . I looked at mine today . It is ancient so maybe not relevant but it has added plates but they are just thicker pieces of steel . I did not check to see if they were hardened but I think they must be as there is little blunting from rocks . On the other hand no chipping either . If they are steel why not just add some hardfacing ? I would opt for just laying beads along it . As for the flights being spring steel sure don't think mine is . Tons of little dings and nicks on them . Again the fact mine came over on the Ark might be the reason . Luck Ken Cutt
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I don't think you need to worry too much about running the temper out of the steel so much as most of the steel used for this kind of application is pretty forgiving. A good source of suitible carbide might come from stump grinder teeth if you run short of the pieces you are turning around. Wrap a wet rag around the steel just below the point where you are soldering. Flux everything and pretin the carbide pieces with enough solder to do the job and hold or position the piece with a piece of carbon rod or finish nail in a wood handle.
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Old Nick wrote:

This the second time today I have suggested Stellite to solve a problem but it is good stuff. :-) I would try building up the tips with Sellite and grinding the ends to the desired shape. I have done similar things with Stellite #6 which, while not the hardest Stellite, does work harden. For example, a center punch I made by welding a blob onto the end of a piece of scrap re-bar and turning it to shape in the lathe with a carbide cutter. It blunted fairly quickly in use so I reshaped it removing as little material as possible. This was a couple years ago and it has remained sharp.
Ted
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Stellite is one of God's gifts!!!
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Another point I forgot to mention: Think of these tines as cantilevers. The greatest bending moment is at the point of support dropping as you move out along the tine. Your welding or brazing will only heat the very end where the bending moment is at a minimum. Since _all_ steel has about the same elastic modulus and you don't need as much _strength_ at the end, you needen't worry about annealing the steel in the heat affected zone.
However you _do_ need to worry about brittleness. I discovered this when I tried to repair a spring. I TIG welded the break with 312 SS wjich is a very strong filler alloy. The re-installed spring quickly failed a very short distance from the weld. Examining the break with a magnifier showed a brittle fracture.
I re-welded the part, and after welding, I cleaned the steel and gently heated the spring in the neighbourhood of the weld 'til I got the blue colour of spring temper. Note that where I heated beyond the potentially brittle area, I was just double tempering the spring. This would have little, if any, effect on the area that was not embrittled.
This repaired spring has now been in service for three or four years without problem.
Ted
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On Fri, 28 May 2004 17:43:53 GMT, Ted Edwards
......and in reply I say!: remove ns from my header address to reply via email
Bah, Ted! (tries not to offend any sects)
Recently, I spat the dummy in my weakness. And here you are, actually following up with, an _informative_ post. AND sort of apologising for missing something!
You make me weep!
No Irony! No Joke!
Fuck you man! You rekindled that flickering belief in humanity as it should be According to OldNick <G>.
I looked up "there is a goodness" on the web, and the leading result was full of stuff about Jews and blacks! I wanted humankind.
Sad huh? But have you ever watched a sick puppy? We love them because they always hope.
Signed: sick puppy.
Maybe I will get over this..............sorry.

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Old Nick wrote:

Is there some point to this?
Ted
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