Nuovo manico DE per vecchi SE: razor hack

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Nuovo manico DE per vecchi SE: razor hack



Nuovo manico DE per vecchi SE: razor hack

Messaggioda ischiapp » 23/01/2018, 23:47

Un argomento che ho cercato per molto tempo, trovando sempre informazioni scarsamente rilevanti.
Fortunatamente su TOST2 è fatto proprio bene:

Per sicurezza, lo copio. ;)
riverrun ha scritto:Disclaimer
This is a work in progress! The latest version can be found here:
It looks nicer than a forum article as well. Read it there instead.
Some of the information in this article may be incorrect.
I have collected information from all over the internet and have not been able to verify all of it. If you find any errors, please let me know.
I don't take any responsibility for any damage you inflict on your collectible razors when trying any of the methods described in this article.

I love my vintage SE razors and some come with really nice handles, but most original handles are quite light and short.
Some of those razors benefit from being paired with a different handle.
My personal favourite is a British made Ever-Ready 1912 razor head paired with a modern 96mm stainless steel handle:

Why not?
So why not use a modern handle on a vintage razor?
The problem is that vintage handles have the screw as part of the handle, whereas modern razors have the screw as part of the razor head.

Grub screws
If both vintage and modern razors used the same type of thread on the screws, all you would need to connect the vintage head to the modern handle is a grub screw.
You'd screw one end of the grub screw into the head and the other end into the handle. They look like this:
Note, that one end of a grub screw has a hexagonal opening. You can use a fitting key or a small screwdriver inserted into this hole to turn the grub screw.
If you ever screw a grub screw into a handle please make sure that the screw goes into the handle so that the hexagonal hole is still visible.
That way you can remove the grub screw should it ever disappear too far down the handle opening.

Different threads
Alas, modern and vintage razor heads and handles sadly do use different threads, so attaching a modern handle to a vintage razor head is not straightforward.
Most modern handles use M5×0.8 threads. There are mainly two types of threads used on vintage razors.
The Ever-Ready 1912 from above, for example, uses American #10-32 UNF threads.
This thread size was used for most 1912s, some 1924 type razors and Valet Autostrop razors .
A smaller thread was used on 1914s, Gem Damaskeene, Gem 1912 travel sets and most lather catchers .
This thread is known as BSW 5/32″×24 and it's a lot of trouble and we'll come to that later.
Don't panic! I'll explain those thread numbers right away, without going into full blown thread theory — as interesting as it may be.

M5×0.8 threads
The metric designation M5×0.8 simply means a thread with 5mm diameter and a thread pitch (the distance from the crest of one thread to the next) of 0.8mm. That's all.
Details on metric threads can be found in the relevant Wikipedia article.

#10-32 UNF threads
The UNF designation #10-32 describes a thread of size #10 with 32 threads per inch.
Size #10 is just an arbitrary number defining a thread of diameter 0.19″ or 4.826mm. 32 threads per inch are equivalent to a thread pitch of 0.7938mm.
All this stuff can be looked up in another Wikipedia article.

BSW 5/32″×24 threads
The British Standard Whitworth 5/32″×24 thread has a diameter of (unsurprisingly) 5/32 of an inch or 3.97mm and a 24 threads per inch — a thread pitch of 1.058mm.
While metric threads and UNF threads share the same general thread shape, BSW threads have a different shape—the angle at which the thread grooves are cut is different.
The biggest problem with this thread is, that it is not actually a standard BSW thread.
A standard BSW 5/32″ thread has a thread count of 32 threads per inch, not 24.
This thread was however used by razor manufactures in the olden days, but tools to make this type of thread are almost impossible to get hold of today.
BSW threads have — of course — also their Wikipedia article

Razors with #10-32 threads
Vintage SE razors with a #10-32 thread are most 1912s, some 1924 type razors and Valet Autostrop razors.
Modern razor handles have a metric M5×0.8 thread.

The difference
Both thread types are very similar to each other.
The diameter is 5mm vs 4.826mm and the thread pitch is 0.8mm vs 0.7938mm.
This raises the question if they are possibly interchangeable?
The answer is “no”, but we might just get away with it.

Using M5×0.8 grub screws
The problem here is, that the M5 grub screw has a slightly larger diameter than the #10-32 hole in the razor head, so it won't go in. At least not very far.
However, I have found that this can be just enough. The M5 grub screw will go in for just over one turn, then stop.
That can be sufficient. Screw on the modern handle and off you go.
Don't force the grub screw as there is a slight possibility to damage the threads in the head. While not ideal, I have used this setup for over a year without any problems.
The grub screw used in this image is 8mm long and 6.5mm of the screw are still visible.
That means only 1.5mm of the grub screw are inside the thread of the head. For our American shavers — that's just under 1/16th of an inch.
In Europe, metric grub screws are easier to get hold of than #10-32 grub screws, but you can easily and cheaply get them on ebay, so next we try…

Using #10-32 grub screws
This time, the grub screw will fit the head perfectly, but it will be too small for the handle. But just by a little bit.
Try this: take a vintage #10-32 handle and screw the thread into a modern M5 handle:
It works. Quite a good fit actually. So a #10-32 grub screw should work alright — and it does.
It easily screws into the head of the razor (hexagonal hole first!), then the modern handle screws on smoothly and firmly.
The grub screws I ordered are 3/8 of an inch (about 9.5mm) long. That size works quite well.
The whole process takes about ten seconds:

Using #10-32 button bolts or screws
Rather than use a headless grub screw that gets inserted into the razor head from below you could use a short screw or bolt with a head and insert it from above.
This is obviously only possible if there is enough space above the hole in the razor head to manoeuvre the screw into position and screw it into the hole of the razor head.
So, I ordered some #10-32 button head bolts.
They are 1/4 inch or 0.635mm long below the head and this should be long enough to go through the hole and into the handle and short enough so they can be manoeuvered inside the head of a 1912 razor — in theory.
In practice, installing the screws is fiddly, to say the least. I wish the bolts had the little hexagonal holes at the bottom of them that the grub screws have.
You could put a small screw driver through the hole in the razor head and turn the screws. This is wishful thinking, so I tried to fiddle.
I tried it on a British made 1912 razor and I failed. This 1912 has very limited space for the screw/bolt inside the head — other razors might be easier to deal with.
I used machine oil to make it easier to get the screw in, I used all sorts of tiny pliers and tweezers to align the screw with the hole in the head and turn it.
After half an hour I came to the conclusion that my fine motor skills are not up to scratch for this task. I'd love to hear from anyone who has achieved this.
If the razor is made from sheet metal — like the 1912 — you can try to bend the metal to make the hole accessible, put the screw in and bend it back.
That's of course barbaric and I won't mention it again.

Razors with BSW 5/32″×24 threads
It all gets a bit more complicated for razors like 1914s, Gem Damaskeene, Gem 1912 travel sets and most lather catchers .
They use British Standard Whitworth 5/32″×24 threads.
The grub screw solutions for vintage razors with a #10-32 thread and M5×0.8 handles only works because both threads are so similar that some people think they are the same.
They are not, but we get away with it.
The BSW threads on our vintage razors have a 3.97mm diameter, the thread diameter on the M5×0.8 handles is 5mm, so a simple grub screw will not work.
The diameter of 3.97mm is very close to 4mm and the thread pitch of 1.058mm is very close to 1mm.
So why not try a M4×1.0 thread?
The simple answer is, that such a thread does not exist as a standard.
We have to find other solutions.

Doing it properly - thread adapters
We could use a “grub screw” with a different thread type at each end. They are called “thread adapters”.
The problem with thread adapters is that they are not easily available, at least not in the thread sizes we require.
The solution would be to make them yourself.
You can make a thread adapter by taking a 5mm rod of a suitable material and cutting threads of the right types onto it.
Cutting threads is done by using a threading wrench and die:
You would cut a M5×0.8 thread on one end of a bit of 5mm rod and cut the correct size thread for the razor head on the other end.
Hey presto - a thread adapter for your vintage razor head:
So far the theory. Unfortunately there is a problem and I haven't come up with an easy solution yet (neither has anyone else, as far as I can tell).
The razors you would want to do this for have the BSW 5/32″×24 thread and there are actually two problems with these threads.
There isn't another standard thread that is similar to our BSW thread and the required BSW 5/32″×24 threading dies are not made anymore and you can't find vintage ones.
For those razors with smaller threads we seem to be stuck, but there are other options:

Using the wrong thread adapter — on purpose
The thread adapter doesn't need to fit perfectly.
If the thinner end of it is thin enough to pass through the hole in the handle, it can be secured by a nut from above.
One option (courtesy of forum user @electrif) is the thread adapter of the “Standard” DE razor:
Those thread adapters have a #10-32 thread for the handle and a #6-32 thread for the head.
The 3.5mm #6-32 thread passes straight through the hole in the head of any vintage SE razor and can then be secured by an (easily obtainable) #6-32 nut.
The end result looks like this:
If you don't own a “Standard” razors (I sold mine, but they are quite good), you can (currently) order replacement thread adapters from their web site.
You could make a suitable thread adapter yourself with threading dies.
Make sure that the thinner end has a diameter of 3.5mm or below.
Thread sizes that should be suitable are UNF #6-32, M3.5×0.6, M3.5×0.35 or M3×0.5.

Brute force - making an M5 hole in the razor head
There is always the option to enlarge the hole in the vintage razor head to M5 size.
You might not want to do this with a rare and highly collectible vintage razor. You might not be able to use the original handle anymore.
Try this on a user grade common vintage razor first.
Cutting a new thread with a larger size is done with a tool called a “tap”.
It comes as part of the “Tap and Die” kit and looks like this:
I'll take some pictures and elaborate when I do this to my spare 1912 razor or if I find a dirt cheap, user grade SE razor with the smaller thread — donations welcome.

Get custom thread adapters made
As a very last resort it would be possible to have a machinist make you custom thread adapters, but I don't know of anyone who has tried this option.
Allegedly this is quite expensive. If you decide to go down this route, please have an additional one made and send it to me.
Nè può essere, dove è grande disposizione, grande difficultà - Niccolò Machiavelli (Il Principe, Cap.XXVI)
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