How they made chisels at Nooitgedagt.

[Kees Heiden]

I saw this up for sale, didn't buy it of course, why would I? But it is interesting. These are the steps of making a drop forged chisel. This was done probably somewhere in the 70's or 80's at the Nooitgedagt factories in The Netherlands. They used to make a lot of chisels back then, at one point they were the largest chisel maker in the world. After they lost the contract from Bahco, the firm quickly went bankrupt.

I don't believe these were very high quality chisels, just your garden variety chrome vanadium cheapies from the home centre.

331109

[Lenore Epstein]

Cool! Thanks for posting the pic.

[mark kosse]

Nice, I would have bought it...

[Kees Heiden]

Well, you still can. They are offered by ducotools.eu. I can't find them on their website yet, but when you email them, I'm sure you will get an answer.

[george wilson]

Same process as Marples. They also start with a round bar.

[Kees Heiden]

I guess they use a similar process at Narex.

Edit: Indeed!


https://www.youtube.com/watch?v=gittWRq2Sjk

[Alfred Kraemer]

Wolfgang Jordan a has short history of the company at holzwerken.de. It is in German but here are some interesting details:

- the company made woodworking tools to help with slow sales in warm winters of their original product line: ice skates.
- in the 1970s they were one of the most prolific chisel producers.
- many of those were sold under different names because many foreign customers couldn't pronouce the company name.
- eventually the company was sold to 'Record' which in turn was sold later.
- when the company stopped producing skates in the mid or lates 1960s, there were so many in storage that 'new' skates were sold until 1975.

Alfred

[Patrick Chase]

I guess they use a similar process at Narex.

Edit: Indeed!

Narex is a bit unique in that their steel is hardened and then given a high-temperature quench (some sources call this an "interrupted" quench) in liquid sodium, with no subsequent tempering. They don't show that in the video though.

[Warren Mickley]

Narex is a bit unique in that their steel is hardened and then given a high-temperature quench (some sources call this an "interrupted" quench) in liquid sodium, with no subsequent tempering. They don't show that in the video though.

Are you saying that the sodium quench does not temper the steel?

[Ray Selinger]

What he saying is Narex by careful choose of steel is doing just a single heat treatment.

[Kees Heiden]

Patrick, please explain that interupted quench. You can go into arcane details here! I know a little about the theory of heat treating and the various ferritic forms like perlite and martensite etc. What does this interupted quench accomplish and how?

[Stewie Simpson]

Kees. I found this info on Salt Bath Quenching.

Stewie;

http://heatbath.com/2012/06/salt-bath-quenching/

[Kees Heiden]

That's very interesting. So, the steel is hold either just above the temperature where austenite transforms to martensite, for a few minutes, and then aircooled to complete the transformation. Or for simpler tool steels that need a faster quench, it is hold just below the martensite start temperature. That transforms all the austenite to martensite inside the salt bath. Those temperatures are around 200 degrees or so, so right within the tempering temperature range of classic heat treating. This process also avoids a lot of the stress in the steel from a water or oil bath. I understand why an extra tempering step would not be neccessary, allthough it wouldn't harm either.

BTW, not really something for the backyard. This stuff is very potent. Could easilly blast the daylight out of you!

[Warren Mickley]

I think there is a lot a lot of confusion in this thread. Patrick talks about using "liquid sodium" after hardening. Stewie talks about salt bath quenching of steel that had been above the critical temperature. Liquid sodium is not a salt. Kees talks as if the quench medium were held at the critical temperature.

[Kees Heiden]

No I write about liquid salt at around 200 degrees, as a quench medium instead of water or oil, just like in that article from Stewie. In fact I was giving a short resume of that text. And I suppose this is what Patrick was posting about too.

And I interpret liquid sodium as one of the sodium salts, like sodium nitrate. But I could be wrong of course.

[george wilson]

Kees,you have such a remarkable grasp of English,though it is not your first language. Sodium nitrate is a correct bath to refer to. Pure sodium is a very active and dangerous metal ! It never can be used exposed to air. They used to put it inside the exhaust valves of aircraft engines as it conducts heat faster away from the head of the valve.

[Robert Norman]

Could easilly blast the daylight out of you!

Might be best to stick to O2 and some cooking oil for us backyard smiths!

[Kees Heiden]

I certainly have no intention of using these salt baths in my back yard! O1 or W1 and oil to quench. Heat up the oil a bit, stir well when quenching. Normalise the steel first, then bring it up to critical again (non magnetic point) and quench quickly. Temper immediately after quenching in the oven. That is the easiest and safest way of heat treating tool steel at home.

And thanks George. I learned a lot of English on this very forum! Best way to learn a language is using it. Now, if I also could learn to type without errors...

[Patrick Chase]

I think there is a lot a lot of confusion in this thread. Patrick talks about using "liquid sodium" after hardening. Stewie talks about salt bath quenching of steel that had been above the critical temperature. Liquid sodium is not a salt. Kees talks as if the quench medium were held at the critical temperature.

I screwed up - it's salt, not liquid Na. Confused my reactor coolants with my quenchant...

EDIT: I also wasn't careful with my wording - "after hardening" should indeed have been "after heating to critical temperature". Stewie's link is to the right thing.