Composite Type?

I have recently purchased a lovely set of Helvetica type and unfortunately it was .933” tall. It’s lightweight, I assumed aluminum so no problem. I machined it down to .918”, but in doing so I discovered its not aluminum. I think it’s a metal-infused composite of some sort. In an attempt to find out if it was zinc I tried melting a damaged piece and was surprised when it lit on fire and crumbled apart. I tested to confirm it wasn’t magnesium BEFORE throwing fire at it.

I was hoping someone out there would know what it is exactly. Thanks!

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It’s probably Zamac or Zamak, an alloy of Zinc, aluminium, magnesium and copper. Rainer Gerstenberg in Germany still casts type in Zamac. The caster that he uses is fired at a very high temperature, and it runs slower. Zamac types are used by bookbinders.

Zamac was also called Mazak for a while in the UK and US, so some type catalogs used that term. (Admittedly, not for .933” Helvetica.)

Suluminum: a compound devised in Germany when bauxite and aluminum reserves were low.

Suluminum: a compound devised in Germany when bauxite and aluminum reserves were low.

Suluminum? Are you sure you have that right? The only legitimate Google hit I get for suluminum is your website. Nothing for Suluminium either. I also tried google books, which searches a huge swatch of human knowledge, but no match there either.

I did get a close match searching archived newspapers; I found an ad for “SO-luminum” that I’ve attached to this post.

Googling for “SO-luminum” provides one better lead, there is a page on the Polish wikipedia for “SO-luminum”, that describes it as “a solder alloy used for brazing aluminum . It consists of tin (55%), zinc (33%), aluminum (11%) and copper (1%).”

As for “famous nazi wartime alloys”, Duralumin is the only one that really stands out (90% to 94% aluminum, 4% copper, 1% magnesium and 0.5% to 1% manganese), but it’s obviously still quite high in aluminum.

image: sol.png


Also found this…

image: sol2.png


not the same material. Developed during WW II in Germany.

Could you post some pictures?

Nick, my point was more that any reference to ‘suluminum’ that I can find leads back to you. Where did you learn about this material? Like I said above, the aluminum alloy that Nazi Germany was famous for was Duralumin, which was used extensively in their Zeppelins because of its high strength and low weight, which seems like it would be a good fit for what Heidelberg was looking for. Are you sure suluminum isn’t a malapropism?

Duralumin was also used by Cornerstone in the UK for furniture and quoins, and then sold by American Printing Equipment (AWT) in the US. And AWT also imported Mazak stamping type for sale.

Parallel Imp is exactly right about duralumin being used by Hawthorn Baker Ltd at Dunstable, in UK, the makers of the ‘Cornerstone’ range of kit. I should add that they also
chemically treated the finished parts to give them an
amazingly hard skin. They did this ‘out the back’ in a slat sided shed where the fumes were actually rotting the wooden structure, the surfaces were sort of soapy. The Lord knows what the solution was. Their equipment was seen as being he very best then available. Very helpful on specials too..

@parallel_imp and @harrildplaten
Re: Duralumin. That’s really useful, thanks. I’d always referred to Cornerstone furniture as aluminium, but now I know better!