Engineering English
STL File
Manufacturing Engineering · Tools, Equipment & Measurements · Last updated: July 30, 2026 · How this entry was written
Definition: A standard file format for representing three-dimensional surface geometry in additive manufacturing. It describes a model as a mesh of triangular facets without color or texture information.
Example in context
“The technician imported the STL file into the printer software to verify the model integrity before printing.”
“Teknisyen, yazdırmadan önce model bütünlüğünü doğrulamak için STL dosyasını yazıcı yazılımına aktardı.”
Where engineers use it
STL files are the primary input format for most additive manufacturing systems. Engineers use them to exchange 3D geometry between design software and slicing tools, ensuring the mesh is manifold and watertight.
Synonyms: stereolithography file, Standard Tessellation Language
In Tools, Equipment & Measurements
A triangulated mesh format that approximates a model surface with a network of flat facets, storing no colour, units or tolerance data. It is the common input for additive manufacturing and rapid prototyping software.
“The prototype was exported as an STL file with a fine chord tolerance, because coarse triangulation left visible facets on the curved surface.”
Practice: can you use “STL File” at work?
During a rapid prototyping session, the 3D printer fails to recognize the model. The engineer suspects the STL file has non-manifold edges. How should the engineer diagnose and fix the file?
Show a model answer
“Ensure the STL file is watertight before starting the slicing process.”
“STL File” in 21 languages
| English | STL File |
|---|---|
| Turkish | STL dosyası |
| French | fichier STL |
| German | STL-Datei |
| Spanish | archivo STL |
| Chinese | STL文件 |
| Arabic | ملف STL |
| Portuguese | arquivo STL |
| Russian | STL-файл |
| Japanese | STLファイル |
| Italian | file STL |
| Vietnamese | tệp STL |
| Hindi | STL फ़ाइल |
| Thai | ไฟล์ STL |
| Indonesian | file STL |
| Korean | STL 파일 |
| Bengali | STL ফাইল |
| Dutch | STL-bestand |
| Swedish | STL-fil |
| Finnish | STL-tiedosto |
| Ukrainian | STL-файл |
Frequently asked questions
What does STL File mean in engineering?
A standard file format for representing three-dimensional surface geometry in additive manufacturing. It describes a model as a mesh of triangular facets without color or texture information. In Manufacturing Engineering, the term carries a usage-frequency rating of 10/10 in the Engineering English library.
How do you pronounce STL File?
STL File is pronounced /ɛs tiː ɛl faɪl/ (IPA). The Engineering English app plays audio for the term and checks your pronunciation with speech recognition.
How is STL File used in a sentence?
Example from an engineering context: “The technician imported the STL file into the printer software to verify the model integrity before printing.”
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