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Bolt Tensile & Shear Strength Calculator
Calculate the ultimate tensile load of metric bolts from ISO 898-1 property-class data, plus a simplified shear capacity estimate. Select bolt size and property class.
Results
Ultimate Tensile Load
Ang pinakamataas na tensile force na maaaring tiisin ng isang bolt bago mabasag:
- Rm — ultimate tensile strength (MPa), mula sa property class
- As — tensile stress area (mm²), mula sa ISO 898-1 / ISO 261
Shear Capacity (Simplified Estimate)
ISO 898-1 defines the tensile and proof-load properties of bolts — it does not specify shear strength. The value shown here is a widely used simplified engineering estimate that takes shear strength as approximately 60% of tensile strength (based on the von Mises criterion, τ ≈ 0.58 σ):
Para sa double shear, i-multiply sa 2 (dalawang shear planes).
⚠️ Shear design note: Actual shear capacity depends on whether the shear plane passes through the threads or the unthreaded shank, on joint slip and plate bearing, and on fatigue loading. Design codes define their own values — e.g. Eurocode 3 (EN 1993-1-8) uses Fv = αv × fub × A with αv = 0.6 for classes 4.6, 5.6 and 8.8 but 0.5 for classes 4.8, 5.8, 6.8 and 10.9, together with partial safety factors. Always verify shear-loaded joints against the applicable structural or mechanical design code, not this simplified estimate alone.
Property Classes per ISO 898-1
| Class | Rm (MPa) | Rp0.2 (MPa) | Typical Use |
|---|---|---|---|
| 4.6 | 400 | 240 | Low-strength, general purpose |
| 5.8 | 520 | 420 | Structural, non-preloaded |
| 8.8 | 800 | 640 | Automotive, machinery (most common) |
| 10.9 | 1040 | 940 | Mataas na lakas na structural |
| 12.9 | 1220 | 1100 | Pinakamataas na lakas (alloy steel) |
Praktikal na Halimbawa
Given: M10 bolt, property class 8.8, single shear
As = 58.0 mm², Rm = 800 MPa
Ft = 800 × 58.0 = 46,400 N = 46.4 kN
Fs = 0.6 × 800 × 58.0 = 27,840 N = 27.8 kN
⚠️ Note: Ito ang mga ultimate capacity nang walang safety factors. Mag-apply ng angkop na safety factors (karaniwang 2–3 para sa static, 4–6 para sa fatigue) para sa mga layunin ng disenyo.
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