WRWeatherstrip ReferenceWeatherstrip profile identification by shape & measurements
Source-backed identification · Schlegel

Schlegel Q-LON: read EN 12365 classification

Explain six code-field meanings as a standard classification reading exercise, not a fit test. See the evidence checklist and fit limits.

Short answer. A Schlegel Q-LON classification such as W 4 3 2 7 6 is a six-field performance description, not a replacement-part code or assurance that a seal fits a particular sash. Schlegel's EN 12365:2003 brochure assigns a separate meaning to every position. source

Decode six positions, left to right

Field Meaning in the Schlegel brochure What not to infer
1 Category of use That the profile attaches to your frame
2 Working range That the existing groove accepts the retaining foot
3 Linear compression force That every window closes with the same force
4 Working temperature range That a tested classification overrides installation conditions
5 Deflection recovery That an old installed strip still meets the grade
6 Recovery after ageing That age, weather exposure or damage can be diagnosed from the code alone

These are Schlegel's six explicitly labelled fields. source The initial W denotes weatherstrip and G denotes gasket in that scheme. source For example, the grade table describes second-position grade 4 as a working range greater than 4 mm and at most 6 mm. source Fifth-position grade 7 denotes more than 90% deflection recovery in the table. source

A practical decoding exercise

Write the published code with spaces between fields, then underline the one specification related to the question you are investigating. For W 4 3 2 7 6, ask whether you need to compare working range (second field), closing force (third), or recovery (fifth or sixth); Schlegel presents them as distinct fields and illustrates the six-place sequence. source Never collapse all six digits into a single quality score.

To move from classification to identification, make a second evidence sheet: current window or door system, seal's actual retaining-base cross-section, measured receiver and observed meeting gap. If those records are missing, a six-field string cannot select an exact replacement by itself. Read the manufacturer product drawing for the actual seal code, then have the relevant system specification checked before any purchase or change.

Decision: known code, candidate, or stop

  • Known classification only: retain the code and manufacturer's document edition but mark the installed profile unconfirmed.
  • Known seal/product drawing as well: compare its attachment geometry with the assembly before seeking matched confirmation.
  • No independent identity or incompatible observations: stop; do not substitute a high-performing classification for physical compatibility.

Edition boundary: This explains Schlegel's presentation of EN 12365:2003, not an independent certification assessment, newer standard edition, or approved fire/smoke application. Published figures here belong to the classification table, never to an untested installed assembly.

Official sources and precise sections

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