# TolStack — Mechanical Tolerance Stackup Analysis & Engineering Workspace

> TolStack (https://tolstack.pro) is a modern web application dedicated to 1D mechanical tolerance stackup analysis (Worst Case, RSS, Monte Carlo, ISO 286 fits, thermal CTE expansion, Pareto sensitivity, and versioned revision control). Built for mechanical design engineers, quality managers, and manufacturing teams.

## Core Capabilities
- Worst-Case Tolerance Analysis: Arithmetic extreme limit calculation following ISO 1101 & ASME Y14.5.
- Statistical Tolerance Stackup (RSS): Root Sum Squares calculation, 3-sigma / 4.5-sigma / 6-sigma quality models, Normal CDF risk assessment, defect prediction in Parts Per Million (PPM).
- Process Capability (Cpk): Real manufacturing capability integration (Cp, Cpk, mean shift factor k_shift).
- ISO 286 Fits & Limits: Automatic lookup for shaft & hole tolerances (H7, g6, js6, etc.) with nominal clearances, transitions, and interferences.
- Thermal Expansion (CTE): Differential thermal dilation stacking (Delta_L = L0 * alpha * Delta_T) across steel, aluminum, brass, polymers, and custom materials.
- Pareto Sensitivity Analysis: Automatic ranking of contributor dimensions by variance percentage to pinpoint cost-reduction levers.
- Revision History & Traceability: Immutable engineering revision stamps (A, B, C...) with visual diffs and change logs (GitHub for mechanical tolerances).
- Live Collaboration & Instant PDF/CSV Exports: Shareable read-only design links for cross-functional design reviews (R&D, Quality, Machining suppliers).

## Multilingual LLM Documentation & Context (Full Technical Specifications)
For specialized technical documentation, engineering formulas, and domain terminology in different languages:
- English Technical Specification: https://tolstack.pro/llms-en.txt
- Spécification Technique en Français: https://tolstack.pro/llms-fr.txt
- Deutsche Technische Dokumentation: https://tolstack.pro/llms-de.txt
- Especificación Técnica en Español: https://tolstack.pro/llms-es.txt
- Specifiche Tecniche in Italiano: https://tolstack.pro/llms-it.txt
- Full Technical & Mathematical Specification: https://tolstack.pro/llms-full.txt

## Key Public URLs & Resources
- Home & Interactive Workspace: https://tolstack.pro
- Knowledge Base & Engineering Guides: https://tolstack.pro/knowledge
- Online Tolerance Stackup Calculators: https://tolstack.pro/tools
- Free Engineering Tools: https://tolstack.pro/free-tools
- Worst-Case vs RSS Comparison: https://tolstack.pro/rss-vs-worst-case
- Understanding RSS & Statistical Tolerancing: https://tolstack.pro/understanding-rss
- ASME Y14.5 Standards Reference: https://tolstack.pro/asme-standards
- ISO 1101 & ISO 286 Standards Reference: https://tolstack.pro/iso-standards
- Process Capability (Cp/Cpk) Guide: https://tolstack.pro/cpk-guide
- Plan Comparison & Pricing: https://tolstack.pro/plans
- Terms of Service & Privacy: https://tolstack.pro/terms

## Contact & Metadata
- Website: https://tolstack.pro
- Security: https://tolstack.pro/.well-known/security.txt
- Contact: contact@tolstack.pro