Core Links Engineering CalculatorsHPに戻るCompany home

CORE LINKS · DESIGN GUIDES

Check a pin joint beyond pin shear

A thick pin does not establish the strength of the whole joint. Separate pin shear from the loads carried by the surrounding plate.

Double-shear clevis section: horizontal plate forces, vertical pin axis, two shear planes and pin diameter.FF/2F/2Dτavgn = 2
Section of a central plate between two outer clevis plates. The pin axis is vertical and plates are pulled horizontally. Red dashed lines mark two shear planes. Outer-plate F/2 assumes symmetric equal sharing.

What you will understand

  • Shear-plane count and load path
  • Whole-joint load versus one plate load
  • Separate shear, bearing, tear-out and bending

Blue: defined conditions · Red: calculated quantities. Diagrams are schematic.

  • F: total transferred load, D: pin diameter
  • n=2: number of pin shear planes
  • τavg: average shear stress per plane

The examples below are illustrative. Each example button loads its fixed values, units and mode. Ordinary calculator links do not load an example.

Draw the load path

First trace total load F through the pin and each plate. The number of parts is not the number of shear planes. Cantilevered arrangements and large gaps can also cause bending.

  • Include external loads, acceleration and repetition
  • Identify the actual effective section, including any thread roots

Compare single and double shear

With equal load sharing, double shear gives half the single-plane average stress. A low stress alone is not approval; compare with appropriate shear allowables and fatigue conditions.

A=πD²/4, τavg=F/(nA)

Example: same 1,000 N and 10 mm pin

Inputs

  • F=1,000 N, D=10 mm
  • Single plane n=1; equally shared double plane n=2

Results

  • Single shear: τavg≈12.732 MPa
  • Double shear: τavg≈6.366 MPa

Pin bending, plate bearing, fatigue, gaps and stress concentrations are excluded. Double shear does not automatically double the strength of the complete joint.

Load the fixed values, units and mode for this illustration. Then edit them for your conditions.

Check each plate around the hole

The centre plate carries total load; symmetric outer plates carry F/2 each only when equal sharing is established. Use pin diameter for projected bearing and hole diameter for net section and tear-out.

  • Bearing: the pin presses on the hole; thickness and pin diameter matter
  • Tear-out: check the ligament from hole to loaded end
  • Net section: check the plate width remaining beside the hole
For practical review

Do not assume equal sharing for asymmetric outer plates, large plate deformation or uneven contact. Nominal stresses do not automatically assess contact distribution, plasticity, code edge distances or pin bending.

Match allowables to the failure mode

Do not treat tensile strength directly as an allowable shear stress. Use limits appropriate to material, condition, cycling and applicable rules. Check the weakest pin/plate condition plus retention and wear.

  • Basis for allowables and safety factors
  • Bending, fatigue, wear, retention, assembly and inspection

Keep a review checklist

This checklist is a personal reminder, not a safety score or an automatic approval. It is not sent or saved.

Continue with another guide

Reference information and illustrative calculations. This content does not guarantee suitability or safety of a design. Confirm the actual materials, component specifications and operating conditions.