Hardening / Tempering 1095 Questions

[Crunch]

Hey, all, I want to get into antique bottle hunting by finding and digging old privy outhouses, and one of the tools used to locate them is a "T" shaped probe made of spring steel that you poke down into the ground and listen/feel for glass and different soil consistency.

You can find them for sale online but a 3-footer will run close to $70 with shipping, so I was considering attempting to make one myself out of some 1095 rod.

It looks like one popular one is about .270" diameter.

My questions revolve around how to temper such a piece about .272" diameter x 36" long to "spring" hardness. I guess to harden 1095 steel, you would heat it to critical/non-magnetic and then quench in water. I think I could pull off the heating and quenching in my coal forge...but...

How would you folks go about tempering this hardened piece to "spring" hardness? Could I get away with quenching it very briefly (maybe in a piece of aluminum roof gutter so that I could quench the whole piece simultaneously) and then pull the whole piece out before it had fully cooled, and go by tempering color? Or will such a task really be too tricky/difficult for an amateur?

Thanks in advance for any advice.

C

 

[The Jeff]

Not to deter you from making one, but you could go to a big box or local hardware and buy a septic probe for 40~ dollars.

That would probably do what you need.

[The Jeff]

[Crunch]

Thanks, TheJeff. I actually thought about just getting a piece of 3/8" rebar, grinding it smooth and using that. But a lot of folks seem to say that a spring steel probe is the way to go. The say it transmits sound/feel better, and I guess there's less danger of it bending/fatiguing.

Here's where I was considering buying one: Commercial link removed.

And here's a review of the probes above, where they go into the supposed benefits of spring steel: Commercial link removed.... Search for oldwestbottles.com

Edited April 28, 2023 by Mod30
Commercial link's removed per TOS.

[BillyBones]

To your original question, from the way i read it you want to harden a piece of steel but leave it hot enough so that the residual heat from the steel will temper it. I do not think that will work. I think that you would be basically be case hardening becuase you did not cool the interior of your bar, you want hardness throughout the entire piece. If that was a feasible method dont you think that is how bladesmiths would be doing it? When making something like a chisel where we let the color run keep in mind that only the business end is being hardened and tempered while trying to keep the struck end "soft".   

Also 30" piece aint no joke trying to get and keep the whole piece to temp. My coal forge i have a hard time getting a 15" knife up to temp even just for and edge quench. Something that long i would get quick and dirty and dig a trench in my yard to use as a forge to get the temp even. 

If it is to big to fit in the oven you can build a long fire and just lay the piece next to the fire to you get the color you want. 

Also, does the whole thing need heat treated? Or will it still work if you only heat treat maybe the first 6" or 8"?

[George N. M.]

There is a technique of quenching just the edge of something, usually a single edge knife, and then leting the heat of the unquenched spine temper the edge.  I have never tried it and it sounds fussy to me.

"By hammer and hand all arts do stand."

[Frosty]

You aren't likely to bend a 30" length of 3/8" spring by hand as milled, talk to a spring shop about buying a drop. Or if you must see what they'll charge for including it in the ovens next time they heat treat a batch of springs.

You'll spend many times as much putting something together to heat treat something like that than buying a commercial one.

Frosty The Lucky.

[Crunch]

Thanks for all the replies and advice, fellas. I suspect that you summed it up spot-on, Frosty, when you said, "You'll spend many times as much putting something together to heat treat something like that than buying a commercial one."

I have to admit that I've done this kind of thing too many times to count: I have welding/cutting/woodworking equipment and just enough blacksmithing knowledge to be dangerous, and I'll say, "Gee, I can make the same thing for half the price" ... and then I jack around buying the material and attempting it myself, only to end up buying the finished item in the end, at a net loss compared to if I had just bought the stupid thing in the first place and not wasted time and money trying to DIY.

I'd bet that the guy who makes and sells these things invested in the equipment to harden/temper them properly, and is recovering his expense by selling them. It's kind of like building a jig to make a one-off of something...most of your money and time is spent building the jig, so you might as well pay the guy who built the jig and made enough "rejects" to perfect the final product.

A couple of last questions before I get out of your hair:

- I found a place where I can buy a 36" x .277" piece of 1095 for about $35 delivered. Do you guys think that this would be more stiff/durable in its "as-delivered" condition (in other words, without quenching/tempering) than for example a piece of A36 MS (or whatever steel drill rod is made of) for this purpose ?

- Could I get away with simply quenching 1095 in water after heating it to critical/non-magnetic and then using it as a "privy probe" ... or would it be likely to be TOO hard/brittle, and possibly break, if I quenched it but did not temper it?

- If 1095 would not be appropriate for a "quenching but not tempering" treatment, is there some other steel, maybe an oil-quenched or air-quenched steel, that I could get away with quenching but not tempering for this purpose? (The reason I ask is, I think I could manage a decent heat-soak and quench, but don't know how I could temper a 36" piece...)

Thank you all very much for your advice. I really appreciate it. And sorry for the long post and for posting the commercial links contrary to the TOS.

Jeff

[BillyBones]

I do not know where you are getting the steel from but when you get steel from a supplier it usually comes annealed. That means it is as soft and easy to work as possible. I can not say if it would be better or worse in an "as bought" condition than A36 but it will bend and not be as springy as if it were heat treated. 

[Frosty]

You aren't the only one who spends more setting up to make something than it'd cost to buy one or a few dozen. Welcome to the club. 

No! Quenching 1095 from critical in water might not survive the quench and will break up un-tempered. As delivered 5160, spring stock is stiffer than mild as delivered, it has quite a bit of chrome in it which doesn't need to be heat treated to be stiff. It's also more forgiving of inpresice heat treatment.

When I was drilling one of the office geologists running a different operation. There were 3, Highway or centerline crew, Airport crew and Bridges and Foundations crew, my normal job. The centerline geologist had a thing for light weight, backpack, equipment so they had to pack probe rods AND a portable auger think gas powered ice auger for soil. Other than being threaded at both ends for handle and tip I don't think there was much special about the steel, they were always getting bent and tossed. They didn't get bent in use they got stepped on or something set on them or pinched on the drill rig, etc. Be honest though I don't think it was an accident most of the time, they were required to drill holes and samples anyway.

Anyway using one is a matter of pushing it straight so hold it close to the T handle and advance it a poke at a time, you aren't going to just shove it a couple feet into the ground. The large T handle is there because they work better with more than one person using them. That takes practice though.

Try going to a big box store or steel supplier and see about picking up a piece of hot rolled round and grind a point on one end. If you weld a ring on the other end you can insert a handle when you need one. We often used 12" pipe wrenches because nobody wanted to pack in the handle.

Frosty The Lucky.

 

[Crunch]

Thank you guys. Yeah, I kind of thought the steel would be delivered normalized/annealed but was hoping it might still be stiffer/springier..

The 5160 looks real interesting...97ksi yield strength and apparently good fatigue life, I gotta go poking around to find some of that maybe. I was hoping someone might point me toward an alloy steel so thank you Frosty.

Will report back and surely pester you folks more. Thanks again.

Jeff

[Frosty]

Another thought occurred about probing for "treasure." If you wish to use sound as a cue try experimenting by wrapping the probe rod in a blanket and tapping a bottle, aluminum pan, etc. with the other. If it isn't distinct enough try connecting a resonator to the other end, say a tin can wired on as an experiment. Even a cardboard box, would amplify the sound.

I do NOT recommend using pipe wrenches as handles, Drop cord wrap would work nicely and heck a small slide hammer would be a piece of cake to make and it'd let you drive through some hard soils.

Frosty The Lucky.

[Crunch]

Thanks, Frosty. I like that idea. I'm almost thinking it might be interesting to somehow combine a cheap Chinese "stethoscope" with the probe, so that the tip of the probe would effectively be an extension of your eardrum. (Might have to stuff some cotton in your ears to deaden it though LOL!)

FWIW, I decided to follow your advice and just buy one of these probes already hardened and tempered. After doing a fair amount of Internet research, I've concluded that the spring tempering, combined with the small diameter and fairly long length (48") are fairly important.

[JHCC]

2 hours ago, Crunch said:

combine a cheap Chinese "stethoscope" with the probe, so that the tip of the probe would effectively be an extension of your eardrum.

A mechanic's stethoscope would be a good place to start; Harbor Freight has a cheap one for about seven bucks.

[Frosty]

Try it before you put a stethoscope on it, it might deafeningly loud. You never know what you'll hit below ground and it al has its own sound. Soil, sand, gravel, cobbles boulders, steel, auto bodies sound very different than old appliances. Yes, I've drilled into all kinds of junk, tens of thousands of old flatware is the oddest sound I recall. 

Just listen to the probe before connecting it directly to your ears.

Frosty The Lucky.

[swedefiddle]

Good Morning,

The best Automotive Stethoscope, is a piece of hose. If it hits a fan blade, no problem.

Neil

[BillyBones]

I used to use a long extension to listen to the engine or trans. Stick it on the engine block or what ever and the other end against my ear. 

I was thinking that most of those mechanics stethoscopes have a long aluminum "probe" stuck in a piece of tube then run to the ear thingys. Take the "probe" out  and attach it to the end of your steel rod. 

[Frosty]

I used a really long screw driver to listen to engines. If I had to listen to something near the fan, say timing chain, I took the belt off.

Heck, wrap a piece of wire around the probe, stick the other end through the bottom of a paper cut and hang it from your ear with a rubber band.

Truth is we never had trouble hearing what the probe was going through or fetched up against, it just takes practice. Remember, no special tool can replace experience.

Frosty The Lucky.

[Jason L]

I made my own probe out of mild steel and it worked just fine till I turned it into something else. I didn't even put a handle on it since I was mostly hunting creek banks and such with soft mud. I just bought a 3' piece of mild steel rod, rounded off the tip and went at it. It worked just fine with no problems at all. I did use it in rocky ground as well as red clay and it still did fine but I mostly hit soft ground with it. 

[Crunch]

On 5/2/2023 at 8:02 PM, Frosty said:

I used a really long screw driver to listen to engines.

That's what I always did too. Seemed to work well.

Got the probe and  now I'm trying to find the outhouse on this old 1892 farmhouse. Found some "soft spots" and dug down to about 18" but didn't find much...I guess it's gonna take a bit of poking around and dry holes!

Thanks again for everyone's help and suggestions.

[Frosty]

May the probing be with you.

Frosty The Lucky.

[ThomasPowers]

Out here in NM we try to AVOID the "probing"....

[Frosty]

Understandable, you folk in that area of NM tend to be on the wrong end of the probing. 

Frosty The Lucky.

[ThomasPowers]

Shall I make you an appointment in Roswell?

[Frosty]

 You have contacts in Roswell? Not to probe into your business, just curious.

A few years ago we had a friend who used to live not far from Roswell and she'd get the most pinched expression any time the name came up. Which was funny as she was a bonified member of the aluminum foil beany club. 

Frosty The Lucky.