# MachineCalcs Agent Guide MachineCalcs is a public, no-login collection of mechanical and machine-design calculators that show their formulas, assumptions, reference data, and supporting guides. ## Scope Boundary MachineCalcs intentionally covers engineering, manufacturing, construction/trades, vehicle, aviation and technical design workflows. Tax, finance, real-estate investing and CRE waterfall/promote/preferred-return/GP-LP split calculators belong to separate properties unless they directly support a technical design workflow. ## Discovery - LLM index: https://machinecalcs.com/llms.txt - Public search index: https://machinecalcs.com/search-index.json - OpenSearch description: https://machinecalcs.com/opensearch.xml - Public calculator API: https://machinecalcs.com/api/calculators - OpenAPI: https://machinecalcs.com/.well-known/openapi.json - API catalog: https://machinecalcs.com/.well-known/api-catalog - Agent skills index: https://machinecalcs.com/.well-known/agent-skills/index.json - MCP server card: https://machinecalcs.com/.well-known/mcp/server-card.json - Auth notes: https://machinecalcs.com/auth.md - Sitemap: https://machinecalcs.com/sitemap-index.xml ## Calculator Hubs - [Springs calculators](https://machinecalcs.com/springs-calculators): 17 tools - [Gears calculators](https://machinecalcs.com/gears-calculators): 23 tools - [GD&T calculators](https://machinecalcs.com/gdandt-calculators): 8 tools - [Machining calculators](https://machinecalcs.com/machining-calculators): 42 tools - [Materials calculators](https://machinecalcs.com/materials-calculators): 33 tools - [Hydraulics calculators](https://machinecalcs.com/hydraulics-calculators): 56 tools - [HVAC calculators](https://machinecalcs.com/hvac-calculators): 21 tools - [Electrical calculators](https://machinecalcs.com/electrical-calculators): 20 tools - [Power Transmission calculators](https://machinecalcs.com/power-transmission-calculators): 19 tools - [Automotive calculators](https://machinecalcs.com/automotive-calculators): 49 tools - [Aviation calculators](https://machinecalcs.com/aviation-calculators): 27 tools - [Electromechanical calculators](https://machinecalcs.com/electromechanical-calculators): 5 tools - [Fasteners calculators](https://machinecalcs.com/fasteners-calculators): 23 tools - [Sheet Metal calculators](https://machinecalcs.com/sheet-metal-calculators): 12 tools - [Structural calculators](https://machinecalcs.com/structural-calculators): 39 tools ## Highest-Value Tools - [Compression Spring Calculator](https://machinecalcs.com/compression-spring-calculator): Rate, Wahl-corrected stress, force, coil-bind travel and buckling, with built-in material data. - [Spring Buckling Calculator](https://machinecalcs.com/spring-buckling-calculator): Compression spring buckling critical deflection, no-buckling free length and required mean diameter from free length, coil diameter and end type. - [Spring Pitch Calculator](https://machinecalcs.com/spring-pitch-calculator): Compression spring body pitch, solid height, active-coil gap, travel to solid and free length from target pitch. - [Spring Design Calculator](https://machinecalcs.com/spring-design-calculator): Back-solve wire diameter and active coils from target load, travel, diameter and spring index, then re-check the rounded shop candidate. - [Spring Force Calculator](https://machinecalcs.com/spring-force-calculator): Compression spring force from deflection, with stress, solid height and buckling checks. - [Spring Deflection Calculator](https://machinecalcs.com/spring-deflection-calculator): Compression spring deflection from load, with stress and travel-to-solid checks. - [Spring Wire Size Calculator](https://machinecalcs.com/spring-wire-size-calculator): Solve required compression-spring wire diameter from target rate, then check stress and travel. - [Music Wire Spring Calculator](https://machinecalcs.com/music-wire-spring-calculator): ASTM A228 music-wire spring rate, force, tensile strength and corrected stress. - [Spring Index Calculator](https://machinecalcs.com/spring-index-calculator): Spring index C = D/d with mean, inside and outside diameter conversion. - [Spring Rate Calculator](https://machinecalcs.com/spring-rate-calculator): Spring rate (spring constant) from wire size, coil diameter and material. - [Spring Natural Frequency Calculator](https://machinecalcs.com/spring-natural-frequency-calculator): Helical spring natural frequency, spring mass, effective moving mass and operating-frequency separation. - [Extension Spring Calculator](https://machinecalcs.com/extension-spring-calculator): Rate, spring index and force at extension including initial tension. - [Extension Spring Hook Stress Calculator](https://machinecalcs.com/extension-spring-hook-stress-calculator): First-pass extension-spring hook and end-loop stress screen from load, wire size, coil diameter, bend radii and entered allowables. - [Spring Constant Calculator](https://machinecalcs.com/spring-constant-calculator): Spring constant from two measured load/deflection points (Hooke’s law). - [Torsion Spring Calculator](https://machinecalcs.com/torsion-spring-calculator): Deflection angle, rate per turn and Wahl-corrected inner-fibre bending stress for a helical torsion spring. - [Belleville Washer Load Calculator](https://machinecalcs.com/belleville-washer-load-calculator): Disc spring load at deflection, flat load, OM set stress and series/parallel stack travel by the DIN 2092 (Almen-Laszlo) method. - [Spring Fatigue Life Calculator](https://machinecalcs.com/spring-fatigue-life-calculator): Goodman/Zimmerli infinite-life screen from Fmin-Fmax: alternating and mean Wahl stress, endurance line and shot-peening effect. - [Gear Generator](https://machinecalcs.com/gear-generator): Generate an involute spur gear profile with live preview and DXF export. - [Gear DXF Generator](https://machinecalcs.com/gear-dxf-generator): Generate an involute spur gear DXF for CAD/CAM from module or diametral pitch. - [Spur Gear Calculator](https://machinecalcs.com/spur-gear-calculator): Spur gear geometry, undercut warning, center distance and DXF export. - [Involute Gear Calculator](https://machinecalcs.com/involute-gear-calculator): Tooth geometry from module/DP and pressure angle, with a tooth-profile render and DXF export. - [Base Circle Diameter Calculator](https://machinecalcs.com/base-circle-diameter-calculator): Involute gear base circle diameter, base radius and base pitch from pitch diameter, module, DP or circular pitch. - [Gear Tooth Calculator](https://machinecalcs.com/gear-tooth-calculator): Involute spur gear tooth thickness, addendum, dedendum, whole depth and undercut margin. - [Addendum Dedendum Calculator](https://machinecalcs.com/addendum-dedendum-calculator): Spur gear addendum, dedendum, whole depth, clearance, outside diameter and root diameter from module, DP or circular pitch. ## Guides And Reference Data - Guides: 61 explanatory engineering pages linked from https://machinecalcs.com/guides - Reference charts: 185 tables linked from https://machinecalcs.com/#charts ## Use Policy For Agents - Public calculators, guides, reference charts, sitemap, and llms.txt may be crawled. - Search and real-time AI answer grounding are allowed. - Model training is not granted by the robots.txt Content-Signal preference. - No account, OAuth flow, API key, or agent registration is required for public pages. - Results are engineering references and are not a substitute for professional review on safety-critical designs. - Standards, code-adjacent and manufacturer-table calculators are screening tools. Adopted local code, current standard editions, supplier catalogs, product listings and professional review control final work.