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CRG Research Report - © 1998-2019, Camaro Research Group

1967-1969 Camaro OEM Window Glass

Primary Author -
Reviewed by the CRG
Last Edit: 15-Sep-2019
Previous Edits: 30-Jun-2007, 27-Feb-2006, 30-Sep-2002,
       17-Aug-2000, 19-Mar-2000, 24-Sep-1999, 13-Aug-1999
Original Release: 23-Dec-1998

Index

Overview

First-generation Camaro window glass was supplied by two manufacturers: Libbey Owens Ford (LOF) and Pittsburgh Plate Glass (PPG). LOF was the overwhelming supplier for '67-'68 models, and the dominant supplier in '69. PPG acted as an alternative supplier of Camaro glass and was the primary supplier in '67-'69 to the sister model of the Camaro, the Pontiac Firebird. Either supplier for could provide glass to either GM division in the event of a shortage, but the only PPG glass use that CRG has verified to date in 1967-68 Camaro is the occasional use in 1967 vent window glass. There was an increase in the amount of PPG glass in '69 Camaros, especially at the Norwood Camaro assembly plant, possibly due to the production of the Firebird moving to Norwood in April of 1969.

LOF continues to do business as a division of Pilkington and has reissued their old glasses under the name Pilkington Classics. During the late 1960's, LOF had a number of automotive glass manufacturing facilities. The primary LOF manufacturing sites for Camaro were LOF Plants 6, 8, and 10. LOF Plant 8 in Toledo, OH (now closed) manufactured laminated glass, tempered float glass, and tempered plate glass, (the differences between these glass types is discussed below) and primarily supplied the Norwood, Ohio assembly plant. Plant 8 was also the only known LOF supplier of laminated windshield glass to both Camaro assembly plants. LOF Plant 10 in Lathrope, CA (also now closed) primarily supplied tempered glass to the Van Nuys assembly plant. The third LOF factory, Plant 6, also in Toledo, OH, supplied tempered glass to both assembly plants (to-date, CRG has found only vent window glass from this factory in Camaros). Of these three LOF factories, only Plant 6 remains open today, and it is this factory that has recently begun remanufacture of period LOF OEM reproduction glass for use in restorations.

Despite the typical use of LOF Plant 8 glass at the Norwood Camaro factory, and LOF Plant 10 glass by the Van Nuys Camaro assembly plant, the evidence from original vehicle research shows that each assembly plant infrequently used glass from the other LOF plant. This was done sufficiently often that glass plant location cannot be used as a primary discriminator for determining glass originality. (However it can be useful "circumstantial" evidence, as a secondary discriminator when combined with production dates, etc.)

While certain aspects of the marking systems of these two suppliers were known, there were many glass details that were not known. We were fortunate to be able to access the expertise of supplier experts for this information. However, certain details had been "lost" due to the passage of time and could only be determined by reviewing and documenting a large population of original window glass.

Automobile Glass Manufacturing Processes

There were three different manufacturing processes used for auto glass during the first-generation Camaro era:
Plate Glass
In the late '60's, it was still in common use, but as a discontinuous process (the glass is made in discrete pieces) manufactured by an older technology, it was gradually being phased out in favor of float glass.
Float Glass
The successor to plate glass, float glass is created in a continuous process of floating molten glass on molten metal, typically tin, that results in higher uniform glass thickness and flatness at a lower cost. Float glass is the predominate type in use currently.
Laminated Glass
The third glass type, used for windshields, is laminated glass, which is fabricated by sandwiching and bonding annealed glass (annealed glass has been processed to reduce residual stress - unlike tempered glass) on both sides of a tough transparent plastic core. (Plastic by itself is too soft to be sufficiently resistant to long-term abrasive wear of windshield wipers, or even car washing.) In the late '60s, laminated glass had already long been in use for windshields for safety purposes, as, upon severe impact, the plastic core of laminated glass retains most of the glass fragments and prevents many previously common occupant injuries caused by foreign object impact to the windshield.
Tempered Glass
Tempered glass results not from a glass creation process, as does plate and float glass, but from a post-processing thermal treatment. In automotive use, both plate glass and float glass are tempered to improve damage tolerance. Glass, by itself, is not damage resistant; it is easily scratched by a hard object, and since glass has a very low fracture toughness, small surface scratches result in failure / breakage at very low tensile stress levels.

However, plate or float glass can be made more damage tolerant by inducing a compressive stress on the surfaces of the glass by means of a thermal treatment. If the surfaces of the glass are placed in a pre-loaded compressive stress state via the tempering process, the inevitable minor surface scratches (cracks) do not experience a tensile stress, and thus cannot easily grow under typical loads. This results in a much more durable, and safe, glass product.

Both tempered float glass and laminated glass remain in common automotive use today. Plate glass is no longer produced for automotive use in the US.  

Government Regulatory Safety Standards

By the mid-1960's, specific safety standards for glass had been enacted into law by individual states as well as by the U.S. Federal government, affecting glass development and usage. However development and passage of the landmark Motor Vehicle Safety Act of 1966 was a prime motivator for many changes during this period. This U.S. legislation also created NHTSA, the National Highway Traffic Safety Administration, a division of the U.S. Department of Transportation (DOT). NHTSA develops federal standards on automobile safety, three of which are recorded in Volume 49 of the Federal Motor Vehicle Safety Standards (FMVSS); Code of Federal Regulations, 571.205. They are standard numbers 205, Glazing Materials (glass); 209, Seat Belt Assemblies; and 108 on Lamps, Reflective Devices and Associated Equipment.

FMVSS Part 205 on glass, which originally took effect on 1 Jan 1968, initially referenced SAE J673 (Jun 1960), an earlier performance specification for motor vehicle glass developed by the Society of Automotive Engineers (SAE). The reference was later changed to ANSI Z26, an update of J673 that is maintained by SAE but published by the American National Standards Institute (ANSI). This performance specification is the one that all manufacturers of vehicles being sold in the U.S. are required to meet. The vehicle manufacturers, in turn, flow this requirement down to the glass manufacturers.

Glass terms previously in use but obsoleted with the advent of Federal glass standards, include:

single-strength
0.090-inch (3/32-inch) thick glass.
double-strength
0.125-inch (1/8-inch) thick glass.

Glass Marks

Federal Marks

The new Federal regulations at the time of the first-generation Camaro required only four types of marks on motor vehicle glass:
  1. the AS (American Standard) number (classified by ANSI Z26 and Part 205),
  2. the M (Model) number (assigned by the manufacturer),
  3. for shaded glass, the start of the AS-1 portion that meets the clarity requirement must be so marked on the windshield (located on the passenger side, and shown in the illustration below from the exterior), and
  4. (eventually, for later glass) the DOT manufacturer number (assigned by NHTSA)
AS-1 Mark on Shaded Windshield   1967 Van Nuys Backlight
Plate Glass, M55 AA
AS1 glass mark   Glass mark photo

State Marks

Historic state regulations, many not yet revoked, required other additional marks, such as "Safety," "Solid Tempered," and "Laminated," as appropriate.

GM Marks

Additionally, General Motors itself required several specific marks on OEM glass, including:
Shaded
Added to tinted GM OEM windshields when they included the upper, dark (non-AS1), tint band. For regulatory purposes these windshields are only AS1 glass below the tint band.
Plate
Added to plate glass for GM OEM applications.
Flo-Lite
Added to float glass for GM OEM applications; Flo-lite is a GM tradename and is not used for other OEM glass.
Soft-Ray
Added to tinted GM OEM glass. Soft-Ray is a GM tradename and is not used for other OEM tinted glass. Tinted OEM glass of this era was green in color, whereas current Soft-Ray glass is blue.
For LOF and PPG to produce glass with GM specific marks with minimum risk and maximum manufacturing freedom, agreements between the suppliers and GM allowed for excess OEM glass that was not purchased by GM to be sold by LOF or PPG on the aftermarket, while retaining the GM tradenames of Soft-Ray and Flo-Lite.

Supplier and non-GM OEM Tradenames

Glass supplier tradenames, like "Duplate," "Solex," "E-Z-Eye," and "SunShade" do not appear on GM OEM glass. Glass tradenames from other OEMs also obviously did not appear on GM glass. For example, "Safeguard," which is a tradename for Chrysler glass.

The "AS" Glass Classifications

The AS (or American Standard) glass codes are listed in the ANSI Z26 standard classification of motor vehicle glass produced by the Society of Automotive Engineers (SAE). Note that ANSI Z26 is a "performance" standard that sets minimum requirements for the functional performance of a product. In other words, it doesn't tell manufacturers how to make the glass but rather what functions the glass must perform. While a number of motor vehicle glasses are listed in this standard, for first-generation Camaros there are only two classifications that apply:
AS-1 Laminated glass, windshield only
Must pass the various ANSI Z26 tests/requirements for windshields, which include impact standards and a minimum of 70% light transmissibility.
AS-1 glass is typically composed of two pieces of 1/8-inch glass laminated on either side of 0.030-inch of PVB plastic.
AS-2 Laminated or tempered glass, side/rear only
This glass is required to pass ANSI Z26 tests for side glass, including side impact requirement and a minimum of 70% light transmissibility. This glass is typically composed of one sheet of thick tempered glass (Solid Tempered) or (not seen on Camaros) two layers of thinner glass laminated to either side of a 0.015-inch PVB plastic core.

LOF Glass Markings

Marks from 1966 through December 1968

Transcriptions of two different examples of the variations of LOF OEM glass markings are seen below in their pre-1969 version (e.g., without the DOT mark). Note that "date/plant" is not literal but indicates the location of the Date and Glass Plant code discussed later. See also the later discussion of marking details, such as hyphen use.
                                          SOFT-RAY
       SAFETY  L    PLATE            SAFETY  L    FLO-LITE
          AS2   O   date/plant         AS-2   O   date/plant
                 F                             F
          SOLID TEMPERED                SOLID TEMPERED
               M51                           M74

DOT code added in calendar year 1969

While not part of the original regulations under Part 205, subsequent revisions required addition of a manufacturers "DOT-xx" code to the glass label. DOT numbers for auto glazing were required to be effective April 1, 1973. The LOF number is 15, and the PPG number is 18. While not required by law, LOF began marking their glass with the DOT number as soon as it was assigned and the glass stencils were updated. This DOT mark is first noticed beginning with January 1969 LOF glass production. We believe that glass on Camaros built prior to January 1969 should not show the DOT mark. An example transcription of DOT marked glass is shown below.
             SHADED
            SOFT-RAY
        SAFETY L   FLO-LITE
          AS1   O    date
                 F 
          SOLID TEMPERED
           DOT 15  M4

LOF Glass Model Numbers

As described previously, vehicle glass was manufactured by three different processes; Plate, Float (Flo-Lite), and Laminated; in both clear and tinted types, and in two different thickness (for Plate and Float). There were 10 different types of glass in common use. LOF assigned model numbers to each type of auto glass, and each type received a different model number mark as required by ANSI Z26. These model numbers are discussed below and summarized in the application table.

Two types of AS-1 glass were used for the windshield; M3 for untinted, and M4 for tinted. Eight types of AS-2 glass were used in the rest of the car. The stronger, 1/4-inch thick, AS-2 tempered glass was normally used in Camaro doors, since the door glass is large and frameless with little support from the car when in the raised position - and is especially vulnerable when the door is being slammed closed. Thinner, 3/16-inch thick, AS-2 tempered glass was normally used in the vent (1967), rear quarter, and backlight (rear window) positions.

These normative practices were sometimes violated. In rare cases the thicker AS-2 glass was substituted in areas where the thinner glass was normally used - perhaps to keep production moving at the glass factory. There are even a few rare cases observed, and then (to-date) only in 1967 model LOS cars, where the thinner 3/16-inch thick glass was used in the doors.

1967-1969 Camaro LOF Glass Models
Model  Rating Tint  Thk    Type             Typical Application
------ ------ ----  ----  ---------------  -----------------------
  M3    AS1    No   1/4   Laminated Plate  windshield
  M4    AS1    Yes  1/4   Laminated Plate  windshield

 M51    AS2    No   1/4   Tempered Plate   door
 M52    AS2    No   3/16  Tempered Plate   vent, quarter, backlight
 M54    AS2    Yes  1/4   Tempered Plate   door
 M55    AS2    Yes  3/16  Tempered Plate   vent, quarter, backlight

 M71    AS2    No   1/4   Tempered Float   door
 M72    AS2    No   3/16  Tempered Float   vent, quarter and backlight 
 M74    AS2    Yes  1/4   Tempered Float   door
 M75    AS2    Yes  3/16  Tempered Float   vent, quarter and backlight

Marking Method

LOF sand-blasted almost all glass marks with a stencil. The only exception was the early '68 model "Astro-Ventilation" mark, which used fired-on white ceramic paint [a thank you for this correction goes to Dan DelGratta of LOF]. Decals are incorrect. Also incorrect is reproduction glass that uses baked on black enamel for marking (often seen on modern glass, and still prevalent for the AS1 mark even on repo glass that has had "correct" marks added). Note that there are some stencil differences from one plant to another. LOF Plant 16, in particular, used a distinctly different stencil from the other LOF plants that supplied Camaro glass. Consistent marking patterns include:

1967-1969 Camaro LOF Glass Marking Patterns
 Windshield        - marked on outside     for viewing from inside

 Side glass        - marked on EITHER side for viewing from inside

 Backlight         - marked on outside     for viewing from outside 

 Astro-Ventilation - marked on inside      for viewing from outside
  logo (early 68) 

LOF Date and Plant Codes

The LOF date code is a two-letter code - a one-letter month code followed by a one-letter year code. For example, a code of NX is interpreted as January 1968.

1966-1970 LOF Glass Dating System

                 LOF Month Code - First Character
           N   X   L   G   J   I   U   T   A   Y   C   V
          Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

                 LOF Year Code - Second Character
   A    Z    X    V    T    N    Y    U    L    I    C    G    J
 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 
 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978
 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991

The "-xx" suffix on the LOF date code is the plant code. "-10" indicates the source was the Plant 10 Lathrope, CA facility that supplied primarily the Van Nuys, CA Camaro assembly line. A "blank" code (no plant code) was used by Plant 8 that supplied all windshields to both Camaro factories, as well as tempered glass primarily to the Norwood, OH assembly line. A "-16" code actually denotes Plant 6 rather than Plant 16 (which didn't exist); this plant supplied mostly vent windows. For unknown reasons, there was an extra 1 prefix in the mask.

Our findings to date show the following marking variations:

The Astro-Ventilation logo was dropped from the 1968 door glass about Nov or Dec '67 production. However, one pane of apparently original May '68 door glass with the Astro-Ventilation logo has been observed in a 05C build. The mating glass on the opposite side of the vehicle is Sep '67 Astro-Ventilation glass. We believe that the May '68 pane had the Astro-Ventilation logo added by LOF to create a matching set, presumably to use up left-overpanes. At least two other late '68 cars have been observed with late 1967 Astro-Vent glass.

The DOT mark was added to most LOF glass during stencil changes made for January 1969 production. However, this addition was not yet a Federal requirement, and a few panes of non-DOT LOF glass have been observed in 1969, but these appear to be the exception rather than the rule.

PPG Glass Markings

The PPG Glass was marked with a combination plant and date code. The format is PP-MMY, where PP is the plant code and MMY is the Month and Year. So 27-29 was made in the Tipton, PA plant in February 1969, 27-109 was made in October 1969. The plant codes and glass model information are:

             PPG Plant Codes

 Plant    Location          Focus
   1    Creighton, PA    OEM windshields
  25    Greensburg, PA   (non F-body)
  26    Crestline, OH    OEM rear/side glass 
  27    Tipton, PA       OEM rear/side glass
  28    Evansville, IN   (non F-body)
  41    Berea, KY        (non F-body)
  81    Oshawa, Ontario  (non F-body)
 
                 OEM PPG Glass Types

            M20.x = untinted side/rear glass
            M25   = laminated windshield glass
            M27.x = tinted side/rear glass

  The .x suffix indicates nominal thickness in 1/32"
      .6 = 3/16-inch thickness
      .8 = 1/4-inch thickness
  The decimal point may be a space, or may be absent, 
  such as:   M20.8,  M20 8,  or M208
Examples of PPG glass marks:
                 SAFETY        Flo-Lite
   Ex #1          AS-2    PPG   26 108
                    SOLID TEMPERED
                        M208
The SAFETY mark, AS code, GM Flo-Lite tradename, and SOLID TEMPERED mark are as described above. "26" is the PPG plant code for Crestline, OH and "108" is the PPG date code, 108=Oct 1968. The M-code is the PPG glass type for untinted side/rear glass at 8/32-inch thick (1/4 inch). Note no decimal point or space prior to the thickness code in this example.
                      SOFT RAY
               SAFETY   PPG   FLO-LITE
   Ex #2       AS-2              27-97
                  SOLID TEMPERED
                       M27 6
In this second example of OEM glass, the GM tradename for their tinted glass, SOFT RAY is the same as used on LOF glass. The plant/date code indicates Tipton, PA glass made in September of 1967. The glass is type M27 (tinted M20) at 6/32-inch thick (3/16 inch).
                      SUNSHADE
                     PPG SOLEX
   Ex #3              DUPLATE
   Replacement       LAMINATED
                   SAFETY PLATE
                  AS1  M30  25 102
                       DOT 18
Third example is of NON-OEM PPG windshield replacement glass. Sunshade and Solex are PPG tradenames. Duplate was a PPG name for early laminated glass. The type for this non-OEM glass is M30, the date is Oct 1972, and the DOT code now appears.  

Acknowledgments

The author particularly wants to acknowledge the help and assistance of Mr. Sig Herliczek of Pilkington LOF and Mr. Frank Lovett of PPG, as well as the helpful critique of the other members of the Camaro Research Group. Many thanks are also owed the large number of Camaro owners who patiently contributed original window glass data to this project, oftentimes enduring repeated contacts for additional information.  

Appendix A
Glass Mark Photos

Ordered from the front of the vehicle to the rear.

1967

1967 Van Nuys Tinted Windshield
Laminated Glass, M4 VZ
1969

1969 Norwood Tinted Windshield
Laminated Glass, M4 YX
Glass mark photo Glass mark photo
 
1967 Norwood Psg Vent
Plant 16 Plate Glass, M52 XZ
1967 Van Nuys Psg Vent
Plant 16 Plate Glass, M52 IA
 
1967 Van Nuys Driver Door
Plant 10 Float Glass, M74 YA
1969 (Plant unknown) Driver Door
Plate Glass, M51 XV
1969 Norwood Passenger Door
Plate Glass, M51 JV
 
1967 Norwood Driver Quarter
Plate Glass, M55 CA
1969 Norwood Driver Quarter
Plate Glass, M52 JV
 
1967 Van Nuys Passenger Quarter
Plant 10 Float Glass, M74 YA
1969 Norwood Passenger Quarter
Plate Glass, M52 JV
 
1967 Van Nuys Backlight
Plate Glass, M55 AA
1969 Norwood Backlight
Plate Glass, M52 JV

 



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