Tolerance Analysis
Information about tolerance analysis (tap briefly to open)
Tolerance analysis – detect tolerances and ISO fits from PDF drawings
This tool analyses technical PDF drawings and automatically detects tolerance specifications, ISO fits, limit dimensions and other manufacturing-relevant information.
The PDF file is processed server-side and automatically deleted after analysis.
What is tolerance analysis used for?
Tolerances and fits are core elements of technical drawings and are critical for manufacturing, quality assurance and assembly.
Typical use cases:
- Inspection of manufacturing drawings
- Digitising technical documents
- Quality control of supplier drawings
- Preparation for CAM, CAQ and QM systems
- Automatic capture of tolerance data
- Analysis of archived drawings
Which tolerance types are detected?
The tool detects different standard-compliant tolerance and fit specifications.
- ISO holes (e.g. H7)
- ISO shafts (e.g. g6)
- ISO fit pairs (e.g. H7/g6)
- symmetric tolerances (±0.01)
- limit dimensions (+0.02 / -0.01)
- IT tolerance grades
- dimension and tolerance specifications in drawings
How does tolerance analysis work?
- Upload PDF file
- Extract text and drawing information
- Analyse OCR and vector text
- Detect tolerance specifications
- Classify fits
- Generate a structured analysis report
Depending on the document type, both embedded text and scanned content are evaluated.
Which information can be evaluated?
- Fit specifications
- Tolerance fields
- Dimensions
- Limit dimensions
- Hole and shaft basis systems
- manufacturing-relevant drawing data
Technologies used
Modern open-source technologies and OCR methods are used for the analysis.
- OCR text recognition
- PDF text analysis
- Regex-based tolerance detection
- Python-based document analysis
Current limitations
- Current maximum file size is 80 MB per PDF file
- By default, the first pages are analysed
- OCR quality depends on scan quality and contrast
- Misinterpretations are possible for certain letter-number combinations
- Very complex documents may require longer analysis times
Detection
- ISO holes and shafts (H7, g6)
- ISO fit pairs (H7/g6)
- Symmetric tolerances (±0.01)
- limit dimensions (+0.02 / -0.01)
- IT tolerance grades