Post-war Triplex Manufacturing Date Codes


Triplex ad 1919 Advertisement 1919

Safety glass windows for cars manufactured under the brandname TRIPLEX all received some form of manufacturing date code. This code was part of their trademark  consisting of the word TRIPLEX combined with a circular formation around a triangular arrangement of the three X’s (= Triple X).

Triplex logo The TRIPLEX logo (with or without circle)

Post-war Triplex glass date codes (1945 – 1969)

Cars made till the late 1970’s can be dated by the code etched on the safety glass. Note that it dates the glass and is only an indication of the cars age, thereby assuming the glass is still original.

TRIPLEX safety glass is either named TOUGHENED or LAMINATED depending on the manufacturing process, but in addition the description PLATE has been introduced after the war for laminated windscreens (initially) intended for the USA. The date coding will be explained on basis of these three descriptions: TOUGHENED, LAMINATED and PLATE.

Year code for post-war TOUGHENED and LAMINATED Triplex glass

The year code systems (described below) was used over a number of decades leading to potential confusion if only the last number of a year had been indicated. Post war items are easily recognisable as from 1945 onwards the BS logo (or “kite mark”) was added below the original TRIPLEX logo.

The year code can be found in the nine letters that make the word TOUGHENED. One dot below a letter gives the year within a particular decade:


  • T = 1
  • O = 2
  • U = 3
  • G = 4
  • H = 5
  • E = 6
  • N = 7
  • E = 8
  • D = 9
  • No dot = 0 (or possibly a dot under a space after the last letter)

This code also works if you have a TRIPLEX windscreen with the (also nine letter) word LAMINATED instead of TOUGHENED.

Quarter code for TOUGHENED and LAMINATED Triplex glass

To further determine the approximate month of production, look for a dot above the TRIPLEX word in the logo on the glass, whereby only 4 letters have been used for the coding:


One dot above T, R, E, or X gives the quarter of the year the glass was manufactured:

  • T = Jan, Feb, March,
  • R = April, May, June,
  • E = July Aug, Sept,
  • X = Oct, Nov, Dec.
Triplex logo 1953 Example: 2nd quarter 1953 with BS logo

Year code for PLATE Triplex glass

A different coding system was applied for the post-war TRIPLEX laminated  windscreens destined for the USA, whereby the year of manufacture was mentioned in two figures. The quarter coding system on basis of the word TRIPLEX was identical to the TOUGHENED and LAMINATED versions.

Triplex 1948         Triplex Plate 1955       Triplex logo 1960
Windscreen 1st quarter 1948      Windscreen 2nd quarter 1955    Windscreen 3rd quarter 1959

Triplex branded glass (after Jan 1969)

The year indication is still identical to the TOUGHENED or LAMINATED system, but the month code changed. The month of manufacture is now indicated by the dots over the word TRIPLEX according a rather complicated system:

image            image             image

Example August 75                    Month coding system                   Later logo with unknown Date Code system

History of UK Glass Manufacturers for the Automotive Industry .

British Indestructo Glass Ltd (to be investigated)

Pilkington (now owned by Nippon Sheet Glass Co., Ltd).

In 1929 Pilkington and Triplex formed a joint company to build a works at Eccleston, St. Helens. Pilkington gradually increased its shareholding in Triplex until by 1965 it became the majority shareholder.

In Pilkington’s Queenborough factory on the Isle of Sheppey in Kent the original glass products were made under various brand names like Triplex, Sigla, Bilglas or SIV. Today they can still supply products with the original trademark. The Queenborough factory has made classic windscreens for the aftermarket since the late 1950s, and still retains the vast majority of the tooling produced ’’in-house’’. The range consists of over 2000 parts including, AC Ace, 1953/63, Mercedes 220 1961/71, Aston Martin DB 4 1958/65 and MG’s to name a few. The specialist factory is certified according to BS EN ISO 9001: 2000 ensuring that all legal requirements are met.

TriplX ad 1948  Advertisement 1948

Triplex Safety Glass Co. Ltd. (Est. 1922).

In 1912 the need for the specialist production of safety glass led to the formation of the Triplex Safety Glass Company to manufacture in Britain on basis of certain French patents for laminated glass. The manufacturing process involved fixing some form of transparent material between 2 sheets of glass, thus triplex glass.

By 1922 “TripleX” manufactured at Hythe Road, Willesden, London, N.W.10. laminated and toughened safety glass, both plate and sheet,  multi-ply and bullet-proof glass, curved safety glass, In addition they executed the shaping, forming and manipulation of “Perspex” and other thermoplastic materials.

Trade names: TripleX, Triplite, TriFlex.

image  Tudor Safety Glass advertisement, 1956.

Tudor Safety Glass Co. Ltd. (Estd. 1935).

Spring Place, Kentish Town, London, N.W.5. Two toughening, ten bending furnaces: electricity, gas. Laminated and toughened safety glass, machinery glassware. Trade name: Vinylex. Tudor has been taken over by Triplex Safety Glass some decades ago and thus belongs to the Pilkington Group of companies.

2 thoughts on “Post-war Triplex Manufacturing Date Codes

  1. Peter Olsthoorn

    On original Jaguar windshields the logo with the “ice creme” can be visible. (also on most of the pictures above) This symbol stands for British Standards Institution (BSI)

    B is rotated 90 degrees and the S is inside the ice creme cone. I haven’t found the I yet !
    Maybe it is a nice addition to this article.

    1. Warren Mauzy

      The “I” is the solid line of the left side of the triangle, I believe. it is apparent on the ’48, ’55 & ’59 examples but not on the examples after 1969 where all sides of the triangle are solid.

      Let me know your thoughts on the matter.

      Warren Mauzy


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