Je, eneo la msongo wa bolti huhesabiwaje?

The tensile stress area As is calculated as As = (π/4) × ((d₂ + d₃)/2)², where d₂ is the pitch diameter and d₃ is the minor diameter of the external thread. This formula accounts for the thread root geometry and gives the effective cross-section for tensile loading per ISO 898-1.

Tofauti kati ya kipenyo cha mstari wa mzigo na kipenyo kidogo ni ipi?

Kipenyo cha ncha (d₂) ni kipenyo ambapo upana wa jino la uzi unasawiana na upana wa pengo — ni kipimo muhimu kwa ulinganifu wa uzi. Kipenyo kidogo (d₃) ni kipenyo kidogo zaidi kwenye mzizi wa uzi wa nje. Kipenyo kidogo huamua sehemu ya msalaba ya msingi wa bolti.

Ni tofauti gani kati ya vipimo vya uzi wa hatua kubwa na uzi wa hatua ndogo?

For the same nominal diameter, fine pitch threads have a smaller pitch (P), resulting in a larger pitch diameter and minor diameter compared to coarse threads. This gives fine pitch bolts a larger stress area — for example, M12×1.25 fine has As ≈ 92 mm² versus M12 coarse (P=1.75) with As ≈ 84.3 mm². Fine pitch threads provide better resistance to loosening from vibration.

Zana ya Uhandisi Isiyolipisha

Kikokotoo cha Vipimo vya Nyuzi za Metric

Tafuta vipimo vyote muhimu vya uzi wa ISO wa metric — kipenyo cha ncha, kipenyo kidogo, eneo la msongo, eneo la msingi — kwa M3 hadi M48 katika hatua kubwa na ndogo.

ISO 261 ISO 724 M3 – M48

Results

Uteuzi wa Uzi

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Kipenyo cha Kawaida d

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Pitch P

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Kipenyo cha Ncha d₂

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Kipenyo Kidogo d₃ (bolti)

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Minor Diameter D₁ (nut)

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Urefu wa Uzi H

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Stress Area Aₛ

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Core Area A₃

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Thread	d (mm)	P (mm)	d₂ (mm)	d₃ (mm)	D₁ (mm)	H (mm)	Aₛ (mm²)	A₃ (mm²)

Jiometri ya Uzi wa ISO Metric

Per ISO 261 and ISO 724, the basic profile of ISO metric threads is defined by the fundamental triangle height H₁ and the pitch P.

Kipenyo cha Ncha & Kipenyo Kidogo

Kipenyo cha ncha d₂ na kipenyo kidogo d₃ cha uzi wa nje (bolti) vinatokana na kipenyo cha kawaida d na hatua P:

The minor diameter D₁ of the internal (nut) thread:

Eneo la Msongo & Eneo la Msingi

Eneo la msongo wa mvutano A_s (kulingana na ISO 898-1) na eneo la msingi A₃ ni:

ℹ️ Note: Eneo la msongo A_s ni eneo la msalaba wa ufanisi linalotumiwa kuhesabu mizigo ya mvutano na uthibitisho wa bolti. Ni kubwa kuliko eneo la msingi A₃ kwa sababu inashirikisha wastani wa vipimo vya hatua na kipenyo kidogo.

Mfano wa Vitendo

Mfano — M12 Hatua Kubwa

Given: d = 12 mm, P = 1.75 mm

H = 0.866025 × 1.75 = 1.5155 mm

d₂ = 12 − 0.6495 × 1.75 = 10.863 mm

d₃ = 12 − 1.2269 × 1.75 = 9.853 mm

A_s = (π/4) × ((10.863 + 9.853)/2)² = 84.3 mm²

A₃ = (π/4) × 9.853² = 76.2 mm²

Kikokotoo cha Vipimo vya Uzi wa Metric | ISO 261/724

Published by Nikolai Shelkovenko on Febuari 15, 2026 Febuari 15, 2026

Results

Jiometri ya Uzi wa ISO Metric

Kipenyo cha Ncha & Kipenyo Kidogo

Eneo la Msongo & Eneo la Msingi

Mfano wa Vitendo

Duka

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