In fact, I bet that some of your favorite razors are made from Zamak.
Like most manufacturers such as Merkur, Edwin Jagger, Muhle, and Parker make some or ALL of their razors from Zamak. These razors last for years, and have some of the best reputations in traditional shaving. Yet, if the razor were made in China, the fact that it is made from Zamak will lead many to conclude, “its made from Zamak and it is cheap Chinese junk!”
These days, with modern Zamak alloys this sentiment is simply untrue.
Are you a Zamak Snob?
Our philosophy has always been to use the best possible materials to meet the razor’s objectives. We only have two razors made completely from Zamak – the Sumatra and the Black Tiger. Many of our razors don’t use Zamak at all. Some use a combination of metals including Zamak. Whatever we use, we make certain that it is the best material for the job.
So, if you are a Zamak snob, you may be missing out on some great razors including everything made by Merkur, Edwin Jagger, and Parker.
Did you know that there are many different types of Zamak?
The name zamak is an acronym of the German names for the metals of which the alloys are composed: Zink (zinc), Aluminium, Magnesium and Kupfer (copper). The New Jersey Zinc Company developed zamak alloys in 1929. … A large problem with early zinc die casting materials was zinc pest, owing to impurities in the alloys. While zamak is held to higher industrial standards, it is still considered by many, a pot metal.
So what’s wrong with that??
For the sake of definition, pot metal is considered any metal that has zinc in it as an alloy. But, the family of alloys known as Zamak, are distinguished from Zink itself, because of their constant 5% aluminium composition.
However, unknown to many, there are various types of alloys, called Zamak. Most modern razors use Zamak 7.
Zamak 3 is the de facto standard for the zamak series of zinc alloys; all other zinc alloys are compared to this. Zamak 3 has the base composition for all Zamak alloys (96% zinc, 4% aluminum). It has excellent castability and long term dimensional stability. More than 70% of all North American zinc die castings are made from Zamak 3.
If the plating remains intact, and the razor is not subjected to trauma, it can last many years. Solingen and Sheffield are the bases for edged steel weapon manufacture in Great Britain and Germany, yet there’s no steel in the Merkur, Muhle, or EJ razors made in these cities.
Today most DE Razors are made of Zamak 7.
The advantages of Zamak 7 to a manufacturer are obvious:
- Zamak 7 is easy to cast.
- The tooling costs less and lasts longer.
- Because Zamak 7 is so inexpensive about 70% of all die cast parts are made from Zamak 3 or Zamak 7.
- Many die casting machines, even ancient ones, can spit out thousands of castings in an hour.
- Zamak 7 is surprisingly strong! Zamak 7 die castings are known for their superior impact strength over competing materials and processes.
- Because Zamak 7 is so easily cast, the manufacturer usually has no need for welding. Welded joints, which are often used in the manufacture of razors for the posts on a head, or for different material types and coatings on handles are much weaker than a solid casting.
- Zamak 7 is quite strong! For instance, Zamak 7 has an impact strength greater than 15X that of aluminum Al380. Many razors are made of this alloy. The yield strength of a bar of material is the maximum stress that can be applied along its axis before it begins to change shape. Yield strength is the amount of stress a piece of steel must undergo in order to permanently deform.
The disadvantages of Zamak to a manufacturer are obvious:
- Zamak 7 is very difficult to plate.
- Nickle will adhere to Zamak 7 much better than chrome, but still will not adhere all that well.
- In order to chrome plate a Zamak 7 razor properly, it is necessary to plate the razor first with copper. Copper adheres extremely well to Zamak, and chrome adheres really well to copper.
- Zamak is considered pot metal (which is perhaps more true of Zink itself,) and therefore not popular with consumers.
- Funny thing though all Merkur and Edwin Jagger razors are made from Zamak 7.
The advantages / disadvantages of Zamak 7 to the consumer are not so obvious:
- If We DoBecause of its high yield strength, Zamak 7 has virtually no malleability. This means that Zamack 7 is not easy to bend. If your razor breaks, the part most likely will have to be replaced instead of repaired and bent back in shape, although it may be more difficult to break it in the first place. (Advantage & Disadvantage.)
- Cost. Zamak 7 costs about a third as much as steel and about half as much as brass. (Advantage.)
- Finish. Unless plated properly, as described above, Zamak 3will lose its coating over time. (Disadvantage)
- BUT these days almost all Zamak 7 razors are plated first with copper as mentioned above.
Why We Use Zamak 12 or Zamak 15 in Global Shave Razors When We Use Zamak at All.
Zamak 12 uses more percentage copper as well as aluminum and magnesium in the alloy with zink. This not only slightly improves malleability but moreover improves the adhesion of the plating and simplifies the plating process. Zamak 12 costs significantly more than Zamak 7, but is worth the investment because the finish and durability of the end product are vastly improved.
Zamak 15 has its own unique advantages. It has a much higher copper and magnesium content still than Zamak 12. It costs a bit more than Zamak 12, which in turn costs more than Zamak 7
Zamak 15 is a zinc alloy of high quality with many advantages: it is comparable to steel in many ways, boasting high tensile strength, more malleability and superior corrosion resistance. It is also very easy to plate.
Perhaps a good example of Zamak 15’s proper use is on the head of our Gemini razor. Because it is both an open and closed comb head, it was both much easier, and far less costly to produce out of Zamak 15 than steel or brass, yet with excellent tensile strength. In short there were many manufacturing advantages and no consumer disadvantages by making Gemini’s head this way.