Specific stiffness & strength API

Computes specific stiffness E/ρ and specific strength σ/ρ — the per-weight merit ratios that drive lightweight material selection. Answers 'How stiff/strong is this material per unit mass?', 'Why does aluminium or CFRP beat steel in weight-critical parts?'.

Price$0.04per request

MethodPOST

Route/v1/engineering/specific-stiffness-strength

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

materialspecific-stiffnessspecific-strengthmaterial-selectionlightweightdensitymerit-indexmachine-design

API URLhttps://x402.hexl.dev/v1/engineering/specific-stiffness-strength

Integration docs

Example request

{
  "youngsModulusGpa": 70,
  "strengthMpa": 300,
  "densityKgM3": 2700
}

Example response

{
  "specificStiffness_E_over_rho_MJkg": 25.9259,
  "specificStrength_sigma_over_rho_kNmkg": 111.1111,
  "youngsModulusGpa": 70,
  "strengthMpa": 300,
  "densityKgM3": 2700,
  "formula": "specific stiffness = E/ρ, specific strength = σ/ρ",
  "interpretation": "Higher E/ρ and σ/ρ mean stiffer/stronger per unit mass — why CFRP and aluminum beat steel in weight-critical design."
}

Input schema

{
  "type": "object",
  "required": [
    "youngsModulusGpa",
    "strengthMpa",
    "densityKgM3"
  ],
  "properties": {
    "youngsModulusGpa": {
      "type": "number",
      "examples": [
        70
      ]
    },
    "strengthMpa": {
      "type": "number",
      "examples": [
        300
      ]
    },
    "densityKgM3": {
      "type": "number",
      "examples": [
        2700
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}