All of the helmets produced during the Third Reich period (M35 , M40 and M42) have a model 31 liner system installed.
Most of the Transitional helmets (M16 and M18) used in the TR period were also upgraded with the M31 liner but examples can be found which still have a three pad leather WW1 liner or a post WW1 improved version of the three pad liner. (Often found in Transitional Polizei helmets). As Transitional helmets have been used throughout the TR period all liner types can be found in them depending on when the helmet was re-issued.
Three versions of the M31 liner exist
- The single band aluminium liner
- The reinforced aluminium liner
- The steel liner
The liner system and terminology
The liner band is fastened to the helmet by 3 rivets. 2 in the front and 1 in the rear. Rivets were first made from brass but these were soon replaced by steel ones. The liner band has 2 D rings or chinstrap bales. These are used to fasten the chinstrap to the liner. The leather itself is riveted to an aluminium band with small aluminium rivets (copper for really early liners). The leather and the band together are a separate construction and can be removed from the liner band without having to take out the complete liner system.
On the inside the rivets have 2 legs slid through a washer and bent in opposite directions. Often a maker mark with a year can be spotted on one of the rivet legs. I would advise not to manipulate the leather too much to go hunting for the markings as they are very hard to spot and even harder to photograph. Do not ruin your helmet.
The leather : Origin and color
So far I have observed two types of leather being used.
- Sheep’s leather : Used throughout the war
- Pigskin : From mid to end war. Pig skin is more textured and thick.
Colors can range from tan (the original color and often still very flexible) to light brown , brown , dark brown and black.
Under the leather you can always find a piece of felt , most likely added for comfort. The felt comes in different colors from grey to brown.
The darker the leather the more the helmet was worn. Sweat will color the leather but also oil products that people used in their hair at the time.
Note ! It used to be a common thing for the first and second generation collectors to use leather treatment products. Such products can have a discoloring effect on the leather. Treated leathers are generally dark and greasy and will smell differently. Treated leather will not endure longer , a lot of liners that were treated in the seventies and eighties are in a worse state today than those that were left untreated.
The best treatment you can give a helmet is by simply keeping it in a stable environment.
Below some examples that show you how the leather can change color. The first helmet on the second row has pigskin leather.
Liner band stamps
Every liner will have 2 stamps in the liner band. Poor stamping and dirt can make the stamps hard or impossible to read.
The stamps are always in the locations pointed out in the photo below , I have observed that occasionally the size stamp and maker stamp switched places.
Leather markings and stamps
Very early leather will have imprinted size stamps (see the next chapter). Most liners will have an ink size stamp on the rear liner tongue.
It is possible that no marking is visible due to the stamp being too weak or worn away.
On the underside of the leather you can also find ink stamps. Most of these are also related to the size of the leather. 1943 or later leather can have an RB Nr stamp. Unit stamps are sometimes found on the underside as well but only on M35 helmets with aluminium liners.
Be careful when manipulating the leather , remember it is over 70 years old and handling it can damage it.
I. The single band aluminium liner (M35 and Transitional helmets)
This liner was already in use before the M35 helmet was being produced. You will find the earliest version in Transitional shells (Double decalled) from 1933 onwards.
Produced from 1935 to 1938 (The 1938 dated are rare) these liners were installed in M35 helmets. The earlier single band aluminium liners have the size imprinted into the leather , the later ones have an ink size stamp. The earliest liners have thicker rivet heads that hold the leather to the ring while the ‘later’ ones have the flat head aluminium rivets that are used up until 1945.
Single band aluminium liners always have square cornered D rings.
Example of a very rare single alu liner with the thicker rivets.
Example of the aluminium flat head rivets which you will find on practically all M31 liner systems.
Examples of an imprinted size stamp only found on the leathers of early aluminium band liners.
II. The reinforced aluminium liner (M35 , early M40 and Transitional helmets)
To fix a serious flaw of the single band aluminium liner (the band often broke near the D ring) the liner was reinforced in that area. We see the first reinforced liners as early as 1938. Production however stopped in 1943 2 years after the improved steel liner went into production.
That said only very few companies continued to produce the alu reinforced liner past 1940. The only post 1940 ones I saw were installed in M40 Quist shells.
The liners produced and dated 1938 and 1939 will have the square cornered D rings. The liners dated 1940 and later will have the round cornered D rings or even one of each !
Below example shows 2 different D rings in a Quist M40 , 1941 dated alu reinforced liner
III. The steel liner (M35 Re-issued , M40 , M42 and Transitional helmets)
The steel liner was produced from 1940 up till 1945. Factories installed the liner in M40’s and M42’s but this liner is also often found in refurbished (also termed re-issue helmets) helmets.
These re-issue helmets were depot stock helmets or battlefield finds that were given new life. In the majority of cases these M35 helmets and M16/M18’s which received a new coat of paint over the first set of decals , sometimes a new decal was applied and a new liner installed.
The 1940 dated steel liners can sometimes be found with square cornered D rings or a mix of 1 round and 1 square cornered.
Below an example of a steel liner with round cornered D rings in an M40.
IV. A collectors guide to World war II German helmet liners
If you want to go deeper into the subject of helmet liners I would advise readers to check out the link below. You need to be a registered member to read it.