What is magnetic dating
There is a significant overlap For the early 1946 lighters, two different base stamps have been identified.The first has no gap between "PAT & 2" whereas the second base has a gap. In mid 1946, two changes occurred, The first was that the size of the lighter was reduced by 1mm (0.04"), the second was the introduction of Chrome plating.These range from the material used, the number of holes in the chimney, the shape of the chimney and the design of the flint wheel, as well as the actual stamping on the insert.All of these can be used to help date the insert, and when used with the case dating chart above can help to give a more accurate date of manufacture.Email Lighters made in early 1946 have a case made from Nickel-silver.
In researching this page I am indebted to many other collectors who have sent me photographs of lighters in their collections that were factory engraved with a date.
The third column in the table below describes the changes in the manufacturing process and the first time it changes, links are provided to photographs showing the detail..
One thing to be aware of is that some people may have swapped inserts between lighters in their collection in the past, so it can be possible to find brand new in box lighters where the insert and case do not match.
I am sure that there are other base stamps out there that I have yet to see, and I have little doubt that there are factory dated lighters that do not fit the years I have shown.
If you do have a lighter that does not match my guide please let me know and I will update the information.