New handles for old (SE) razors

Why?

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.
If you buy grub screws to use with razors, make sure they are made from stainless steel or some other material that doesn't corrode. If they are black, they are probably made from carbon steel and will rust.
You can make a grub screw yourself by taking a normal screw with the desired thread and cutting off the head.

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. Another useful thread size is 2BA. To my knowledge it is not used in any razors, but it can be used as a replacement for both #10-32 and M5×0.8 threads.
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

Actual measurements on vintage razor handles make me believe the claim that razor handles have BSW ⁵⁄₃₂^″×24 threads is false. I will have to find out more and then update this article. Watch this space.

2BA threads

The BA standard was proposed by the British Association in 1884 and it is still occasionally used in the UK. If you play darts — a 2BA thread is used to connect the metal barrel of a dart to its shaft. Those 2BA threads can also be useful for our purposes. The vital statistics are: a thread diameter of 4.70mm and thread pitch of 0.81mm (which is equivalent to 31.36 threads per inch). There is—obviously—a Wikipedia article on BA 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 ¹⁄₁₆^th of an inch.
In Europe, metric grub screws are easier to get hold of than #10-32 grub screws, but sometimes you can get them cheaply on ebay (make sure they are made from stainless steel). A German source for stainless steel #10-32 grub screws is this web site, a site I have not used myself. 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. Forum member @fancontroller was more successful. This a Gem Junior Bar razor, but this is an M5×0.8 bolt and the hole in head had been enlarged to 5mm (we'll come to this later).

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.

Using 2BA grub screws

2BA grub screws seem to be an odd choice, as they neither fit the #10-32 hole in the vintage razor head, nor the M5×0.8 hole in the modern handle. But the good news is that they are slightly smaller (4.70mm) than the #10-32 (4.826) and the M5×0.8 (5.0mm). The difference seems big (6% thinner than M5) but in practice it doesn't matter. The 2BA grub screws fit both the head and the handle quite well. If you can get your hands on stainless steel or brass 2BA grub screws, they are a very good choice. I ordered stainless steel 2BA grub screws with a length of ³⁄₈ of an inch from this UK website and they work well. If you can only get normal 2BA screws you can cut off their heads and use them that way, but grub screws with their hexagonal holes are my preference, as they can't be lost inside the handle (if inserted correctly).

It all gets a bit more complicated for razors like 1914s, Gem Damaskeene, Gem 1912 travel sets and most lather catchers. It has been said that they use British Standard Whitworth ⁵⁄₃₂^″×24 threads. The grub screw solution 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. There are reports that there are “#8 sheet metal screws” that will fit. See the section on how to “make your own handle” for more thoughts on those sheet metal screws.

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 head, it can be secured by a nut from above. One option (courtesy of forum member @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 (sadly, no longer) 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.

Extreme brute force — welding a nut to the razor

One extreme method of attaching a handle was spotted on a razor acquired on eBay. Someone welded a nut to the underside of the head. While this works, it completely ruins the razor and is an act of barbarism. There are plenty of gentler options I have pointed out above. Luckily this was not a particularly rare model.

Make your own handle — or have someone else do it for you

If you have a lot of talent and resources, you can make complete replacement handles for your razors. That's what @jayaruh (on several forums) does. The handle is turned from wood, a “#8 sheet metal screw” with the top removed is screwed into the handle and a metal ferrule made by another forum member (@twhite) is added. The result looks quite good.

There is one very minor concern about this approach. The diameter of those sheet metal screws is 4.17mm instead of the correct 3.97mm and those screws are designed to cut through sheet metal—they are self-tapping. The first time you screw one of those handles into a vintage razor head with a BSW ⁵⁄₃₂^″ opening, you need to apply a little bit of force. This probably strips a tiny portion of the original thread. This is not really a problem, as you can't really tell and the original handle will still fit just fine. If this bothers you, don't use sheet metal screws. I'm happy with this solution and a proud owner of one of those handles.

Get custom thread adapters made

As a very last resort it is possible to have a machinist make you custom thread adapters. This is probably not going to be cheap unless you know the machinist well. Here is an example of an adapter custom machined from brass in Italy:

There are now custom thread adapters that you can buy. Forum user GAW9576@TOST3 makes and sells adapters.
One end is #8-24 and the other end is #10-32. This configuration makes the adapter—sort of—fit all vintage razors. If you have a 1912, the #8-24 bit will disappear through the hole in the head until the #10-32 bit engages. If you use an older lather catcher, the #8-24 bit will engage. That's quite neat—I thought. I was however informed that the original idea was that for a 1912 type razor the #8-24 end goes into the handle until the #10-32 bit engages and then the 1912 head is attached. Both ways work.

There is a catch though. The #8-24 thread is too big. The number of threads (24 per inch) is correct, but #8 has a diameter of about 4.17mm, whereas the BSW ⁵⁄₃₂^″ opening is 3.97mm. We now have a similar problem we had with the “#8 sheet metal screws” above. However, the adapters are not self-tapping, so no harm should be done to your precious lather catchers. For many razors the adapter will fit just fine, but sometimes they will only engagge for a single turn of the #8-24 end.
Contact GAW9576@TOST3 if you want one.