Buy some Silver Steel, I always have a stock of many sizes.  Very easy to harden & temper if needed,  as John says if you need to protect the surface use black lead or powdered chalk mixed with meths and painted on. But for most things it’s not necessary.

John

PS how much do you need and where are you ?

400 series will be strongly attracted to a magnet.

Though generally thought to be non-magnetic, 300 series can show slight magnetism.

That may allow you to identify the family of stainless that you have – though there are more exotic types beyond 300 & 400 series.

for avoiding scale heating the part covered in Borax works for me.

I usually put the part into a metal ‘tray’, then cover with a paste made from borax and meths.

I have a small enamelling kiln that I use for heat treating, but just heat and quench as usual.

The borax doesn’t seem to affect the hardening, and the glassy residue scrapes off fairly easily afterwards.

Dave

I agree with Jason, for filing buttons always use unhardened mild steel. The buttons are sacrificial.

The best thing you can do with the stainless steel is recycle it. You don’t know what it is so why waste time with a material that may well be a pig to machine.

Julie

IIRC it’s from the side of a microwave oven we used to have. It died, but I salvaged the stainless cover…

Any thinish metal sheet that will stand the temp will do, doesn’t have to be stainless. The trays are reusable to an extent, but I considerer them disposable – as in when they look dodgy Ill just make some new ones.

The corners are just folded up and round – so the net is a simple rectangle.

Dave

On 16 December 2025 at 11:37 Dave S Said:

for avoiding scale heating the part covered in Borax works for me.

I usually put the part into a metal ‘tray’, then cover with a paste made from borax and meths.

 

 

Dave

It’s a strange thing about Borax. I wanted some about 15 years ago and couldn’t find any for sale over here. I did though manage to add a tin of it to an order for some other items from Germany.

A more recent search came up with this.

https://www.baldwins.co.uk/baldwins-borax-powder?msclkid=aa8d7b5bef751b750292121a4cc82c7c&utm_source=bing&utm_medium=cpc&utm_campaign=S%20-%20Search%20-%20Best%20Seller&utm_term=Borax%20powder%20500g&utm_content=Borax%20Powder#

And this???

https://homeownercosts.co.uk/borax-banned-uk/

It would seem borax is banned as a cleaning agent in the UK, but readily available for other purposes (including, bizarrely, as an additive for caviar).

It isn’t easy to find any definitive answers to the status of borax here even on the ECHA (European Chemicals Agency) website – this article explores the subject:

Is Borax Safe or Toxic? Why Is Borax Banned In U.K.?

I bought a kilo of borax a few months ago: https://www.cooksongold.com/Jewellery-Tools/Borax-Powder-1kg-prcode-998-116;jsessionid=32253D099919851230A7B4A8F183E0DB#description

Dave

C45 steel is (in the netherlands) “easy” to get and can be hardened like silver steel, quench in water. After hardening, silver steel is a bit harder than C45.

There are tool steel types than are also easy to harden by quenching in water or oil, depending on the type.

Soft soap, the potassium based stuff, is a recommended substance for reducing scaling of steel when hardening. It’s also suggested that the carbon content improves surface hardness.

As far as I can tell there is no ban on Borax, so I suspect that is internet hype.

It is not on the restricted SVHC list as far as I can find. It is on the unrestricted 2025 reach candidates list, but that doesn’t mean its restricted, just that its in the list of substances of concern.

Information is available here:

https://chem.echa.europa.eu/100.129.152/overview?searchText=1303-96-4

Dave