Bolt head types guide
Fasteners
Compare hex, socket head, button head, and countersunk bolts for design, assembly, and service access.
Calculator tabs
Doc version: 1.0 | Updated: 2026-02-07
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Bolt Size & Torque
Calculate stress area and preload from nominal diameter, pitch, and grade.
Input Parameters
Calculate core bolt values from size, property class, and friction assumptions. Results update automatically as values change.
Choosing a preset fills d and P automatically; you can still edit both fields.
Hesap Sonuçları
Sonuçlar yaklaşık formüllerle hesaplanır. Kritik uygulamalarda standart tablolarla kontrol edilmelidir.
Gerilme alanı As36.6 mm^2
Ön yük Fv16.40 kN
Önerilen tork T32.8 Nm
Çekme gerilmesi sigma448 MPa
Güvenlik katsayısı S1.43
Metrik dişler için gerilme alanı yaklaşık olarak hesaplanır. ISO 898-1 gibi standartlar ve OEM tablolar ile doğrulama önerilir.
Explanation Mode (advanced)
Formulas used
As = (pi/4) * (d - 0.9382 * P)^2
Fv = preload * Re * As
T = K * Fv * d
sigma = Fv / As
S = Re / sigma
Variables
- d
- Nominal çap (mm).
- P
- Diş adımı (mm).
- As
- Gerilme alanı (mm^2).
- Re
- Akma dayanımı (MPa).
- Fv
- Ön yük (N).
- K
- Sürtünme katsayısı (tork faktörü).
- T
- Tork (Nm). d metreye çevrilerek kullanılır.
- sigma
- Çekme gerilmesi (MPa).
- S
- Güvenlik katsayısı.
Usage notes
- Metrik dişler için yaklaşık gerilme alanı formülü kullanılır.
- Sürtünme katsayısı, yağlama ve kaplamaya göre değişir.
- Kritik uygulamalarda standart tabloları referans alın.
Show reports, charts, and comparison tools
After checking the basic result, open sharing, PDF, method notes, and comparison panels.
Standard Documentation
Bolt Size & TorqueScope: What does this tool calculate?
Calculates bolt stress area, preload estimate, and tightening torque estimate.
Assumptions and Units
- SI units are used (N, mm, MPa, Nm).
- Thread geometry and friction values use typical defaults and must be adjusted per application.
- Material grade mechanical properties are interpreted against ISO 898-1 references.
Limits / Boundaries
- Torque-preload relation is highly friction-sensitive; real assembly requires calibration.
- Dynamic fatigue, relaxation, and service temperature effects are limited in this quick model.
Reference Standard
- ISO 898-1
- VDI 2230
- ISO 68-1 / ISO 261 (metric thread baseline references)
Validation Example
M10 - class 8.8 check
| Input | Expected Output |
|---|---|
| d=10 mm, p=1.5 mm, target preload=25 kN, friction=0.14 | As around 58 mm^2, estimated torque around 45-55 Nm |
Note: For final torque, verify with field friction data and wrench calibration.
Version and Update
- Version
- v1.0.0
- Last updated
- 2026-03-04
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Calculation explanation
How to use
- Select the bolt size (d, P) and grade.
- Set preload percentage and friction condition.
- Check stress area, preload, and torque outputs.
Formula
As = (π/4)·(d - 0.9382·P)^2 | Fv = (preload/100)·Re·As | T = K·Fv·dCommon mistakes
- Entering preload as 0.70 instead of 70%.
- Picking the wrong friction condition.
- Mixing units for d and pitch.
References
- ISO 898-1 (Mechanical properties of bolts)
- VDI 2230 — Practical reference for preload and torque.
Confidence SnapshotVersion: 1.0
Last updated: 2026-02-07
References
- ISO 898-1 (Mechanical properties of bolts)
- VDI 2230 — Practical reference for preload and torque.
Assumptions
- Preload is static and axial.
- Friction factors are typical values.
Guides
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Coefficient of Friction is a core engineering term. Definition, usage notes, and a practical example.
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Shear Stress is a core engineering term. Definition, usage notes, and a practical example.
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