Help Please

[roy cobb]

Ok the other day I get home from work and my wife asked me to find an acupuncture needle that was lost in our horse paddock ( I know WTF ) well after sweeping for some time as she was not sure where it was I found it Now the interesting part it would not make a sound with the detector or even my pinpointer but it will stick to a magnet so what metal is it and by the way I found a needle similar size in my wife sowing kit and it set the pointer off :/

 

[Redfin]

Now the interesting part it would not make a sound with the detector or even my pinpointer but it will stick to a magnet

So how did you find a needle in a paddock without assistance from the detector or pinpointer??

 

[roy cobb]

Finally found it by sight only as I was increasing search area

 

[jm9422]

wow, talk about finding a needle in a horse paddock.

You'd probably be able to spot colour in a fast flowing creek.

 

[roy cobb]

wow, talk about finding a needle in a horse paddock.

You'd probably be able to spot colour in a fast flowing creek.

LOL Yes I was very lucky as if I did not find it my wife would probable got rid off my detectors I have searched Google that did not help and the needle is flexible as you would expect

 

[grubstake]

Ok the other day I get home from work and my wife asked me to find an acupuncture needle that was lost in our horse paddock ( I know WTF ) well after sweeping for some time as she was not sure where it was I found it Now the interesting part it would not make a sound with the detector or even my pinpointer but it will stick to a magnet so what metal is it and by the way I found a needle similar size in my wife sowing kit and it set the pointer off :/

An acupuncture needle would most likely be made from stainless steel (https://en.wikipedia.org/wiki/Acupuncture#Needles). Sewing needles are usually nickel-plated high-carbon steel (https://en.wikipedia.org/wiki/Sewing_needle).

 

[roy cobb]

Ok the other day I get home from work and my wife asked me to find an acupuncture needle that was lost in our horse paddock ( I know WTF ) well after sweeping for some time as she was not sure where it was I found it Now the interesting part it would not make a sound with the detector or even my pinpointer but it will stick to a magnet so what metal is it and by the way I found a needle similar size in my wife sowing kit and it set the pointer off :/

An acupuncture needle would most likely be made from stainless steel (https://en.wikipedia.org/wiki/Acupuncture#Needles). Sewing needles are usually nickel-plated high-carbon steel (https://en.wikipedia.org/wiki/Sewing_needle).

I have tried 304 and 316 s/s with my pinpointer and it goes off but not with this needle

 

[Paulmarr]

There are heaps of needles in the beach and none of my detectors pick them up but I am discriminating out iron ....

 

[Goldpick]

The picture might explain why you can't pick it up on the detector or pinpointer, I'd say it is simply too fine for either to come up with a response.

 

[Nightjar]

Roy Cobb, Unless I've missed it, what detector were you using?

 

[Ramjet]

Roy Cobb, Unless I've missed it, what detector were you using?

x terror 705

 

[Mackka]

Hey GP I take it that the diagram is a mixture of width and length.
Cheers
Mackka

 

[roy cobb]

Thanks Ramjet you are right

 

[Goldpick]

Hey GP I take it that the diagram is a mixture of width and length.
Cheers
Mackka

Yep, a mixture of measurements there. My Infinium would probably pick that up with a mono coil, it loves stupidly small bits of wire. A higher frequency vlf should also pick up on the needle (thinking gmt, gold racer, GB2), lower frequency vlf's less so. We had a similar discussion a while ago about finding a suitable detector to pick up on dress making pins in garments.

 

[XIV]

The picture might explain why you can't pick it up on the detector or pinpointer, I'd say it is simply too fine for either to come up with a response.

https://www.prospectingaustralia.com/forum/img/member-images/1695/1476349336_images.jpg

there is no way that syringe is going anywhere near me, but on another note, how easy would it be to start the fire with those matches, just don't light a smoke with it 8)

 

[RM Outback]

If a magnet will pick it up its not stainless, has to be ferrous if that's the case.

 

[The Green Wanderer]

Its probably made of 316 stainless, which does contain iron but in very very low amounts. Theres more nickel and titanium in 316 than iron that coupled with the thinness of the needle to begin with would make it next to invisible to a coil or pinpointer.

Cutlery grade stainless, 18/8 or 18/10 is magnetic as its a more than likely a high carbon steel coated with nickel and or chromium so that its not too soft to cut but still has some resistance to rust.
Even the most expensive forged blade professional and sport knives are not impervious to rust. True that they use a Chrome Moly Vanadium steel but will rust if left in a puddle too long. The upside of that is that the rust can usually be removed easily with a Scotch Brite scourer.

The main trouble with stainless of any grade is that there is next to no international standard for what constitutes stainless. So every manufacturer has a slightly different steel composition and therefore different properties.

Would be interesting one day to line up a selection and test their individual qualities.
TGW.

 

[Old Fred]

Its probably made of 316 stainless, which does contain iron but in very very low amounts. There''s more nickel and titanium in 316 than iron that coupled with the thinness of the needle to begin with would make it next to invisible to a coil or pinpointer.

Cutlery grade stainless, 18/8 or 18/10 is magnetic as its a more than likely a high carbon steel coated with nickel and or chromium so that its not too soft to cut but still has some resistance to rust.
Even the most expensive forged blade professional and sport knives are not impervious to rust. True that they use a Chrome Moly Vanadium steel but will rust if left in a puddle too long. The upside of that is that the rust can usually be removed easily with a Scotch Brite scourer.

The main trouble with stainless of any grade is that there is next to no international standard for what constitutes stainless. So every manufacturer has a slightly different steel composition and therefore different properties.

Would be interesting one day to line up a selection and test their individual qualities.
TGW.

All stainless ,even 316 will rust if scratched with mild steel (actually electrolysis sets in )

 

[BigWave]

Correction there TGW. Stainless steels typically contain at least 60% iron (316 is around 66% iron), but it's the phase (microstructure) of the iron that counts. Ferritic & Martensitic phases (i.e: 409 and 420) are strongly magnetic, whilst austentitic phase (viz: 304 and 316) are only very weakly paramagnetic. So, oils ain't oils - Sol!

 

[Redfin]

Which is why you carry a pocket magnet when buying a BBQ, etc