ASTM D4562
ASTM D4562 — Shear Strength of Adhesives Using the Pin-and-Collar Method
1. Scope and Purpose
ASTM D4562 is a standardized laboratory test method used to determine the shear strength of liquid adhesives in cylindrical bonded assemblies, most commonly representative of retaining compounds, thread-locking adhesives, and press-fit style joints. The method evaluates the resistance of an adhesive bond to axial displacement, producing a predominantly shear stress state along a cylindrical bond interface.
This test is widely used in mechanical fastening, automotive, industrial assembly, and manufacturing quality control environments where adhesives are relied upon to prevent relative motion between concentric components.
2. Principle of the Test
The test utilizes a pin-and-collar specimen in which a cylindrical pin is bonded inside a slip collar using the adhesive under evaluation. After curing, the specimen is placed into a compression shear fixture, and an axial compressive load is applied to the pin using a universal testing machine.
As load increases, the adhesive joint resists motion through interfacial shear stresses developed along the cylindrical bond line. The test continues until the adhesive bond fails and the pin is displaced relative to the collar. The maximum force sustained prior to failure is recorded and used to calculate the apparent shear strength of the adhesive.
3. Test Specimen Geometry and Materials
3.1 Specimen Configuration
The D4562 specimen consists of two primary components:
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Pin: A cylindrical rod bonded into the collar
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Slip Collar: A short cylindrical sleeve providing the bonded overlap length
Typical commercial specimens conform to the following nominal dimensions:
| Component | Typical Dimension |
|---|---|
| Pin diameter | ~0.498–0.499 in (12.65–12.67 mm) |
| Collar inside diameter | ~0.500 in (12.70 mm) |
| Collar width (bond length) | ~0.435–0.439 in (11.0–11.15 mm) |
| Pin length | ~2 in (50 mm) |
The bonded area is the cylindrical interface between the pin outside diameter and the collar inside diameter across the collar width.
3.2 Materials
Specimens are commonly manufactured from carbon steel (e.g., A108) to ensure repeatability and dimensional stability. However, alternate materials may be used if required by an application, provided material selection and surface condition are clearly documented.
4. Adhesive Application and Specimen Preparation
Specimen preparation has a significant influence on test results and must be carefully controlled.
Key preparation variables include:
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Surface preparation
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Degreasing, abrasion, chemical activation, or priming per adhesive manufacturer recommendations
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Adhesive application
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Applied to one or both mating surfaces as specified
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Assembly method
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Controlled insertion speed and alignment to ensure uniform bond thickness
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Curing conditions
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Cure time, temperature, and humidity must be recorded
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Conditioning prior to test
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Specimens should be tested in a controlled laboratory environment unless otherwise specified
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Consistency across specimens is critical for minimizing data scatter and ensuring meaningful comparisons.
5. Test Fixture and Apparatus
5.1 Shear Compression Fixture
The test requires a pin-and-collar compression shear fixture designed to:
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Rigidly support the collar and prevent axial motion
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Apply axial compressive force directly to the pin
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Maintain concentric alignment to minimize bending stresses
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Provide clearance for pin displacement after bond failure
The fixture must be sufficiently rigid to prevent deformation that could influence the measured force.
5.2 Universal Testing Machine
ASTM D4562 is performed using a universal testing machine (UTM) configured in compression. Acceptable machines include electromechanical or servo-hydraulic systems with appropriate load capacity.
Recommended UTM configuration:
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Compression platens or guided compression tooling
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Load cell sized so peak loads fall within the optimal accuracy range
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Data acquisition capable of recording force versus displacement
6. Test Speed and Loading Conditions
The standard specifies a constant crosshead speed, commonly:
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0.05 in/min (1.3 mm/min)
Maintaining a consistent loading rate is important, as many adhesives exhibit rate-dependent behavior. Any deviation from the specified speed must be clearly reported.
7. Test Procedure Summary
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Measure and record pin diameter and collar width for each specimen
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Prepare surfaces and assemble specimens using controlled procedures
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Cure and condition specimens as required
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Install specimen into the compression shear fixture
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Apply compressive load at the specified crosshead speed
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Continue loading until adhesive bond failure occurs
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Record the maximum force (Pmax)
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Visually inspect and document the failure mode
8. Calculation of Shear Strength
8.1 Bonded Area
The bonded area is calculated as the lateral surface area of a cylinder:
A=πdLA = \pi d LA=πdL
Where:
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ddd = pin diameter
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LLL = bond length (collar width)
8.2 Apparent Shear Strength
The apparent shear strength of the adhesive is calculated using:
τ=PmaxπdL\tau = \frac{P_{\max}}{\pi d L}τ=πdLPmax
Where:
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PmaxP_{\max}Pmax = maximum force prior to failure
This value represents an apparent shear strength, as stress distribution along the bond line is not perfectly uniform.
9. Example Calculation
Assume:
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Maximum force: 4,200 lbf
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Pin diameter: 0.499 in
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Bond length: 0.437 in
Bonded area:
A=π×0.499×0.437≈0.685 in2A = \pi \times 0.499 \times 0.437 \approx 0.685 \text{ in}^2A=π×0.499×0.437≈0.685 in2
Shear strength:
τ=42000.685≈6,130 psi\tau = \frac{4200}{0.685} \approx 6,130 \text{ psi}τ=0.6854200≈6,130 psi
10. Failure Mode Evaluation
Failure mode should be documented for each specimen and may include:
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Adhesive failure (separation at the adhesive-substrate interface)
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Cohesive failure (fracture within the adhesive layer)
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Mixed-mode failure
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Substrate deformation or galling
Failure mode analysis provides valuable insight into adhesive performance beyond numerical strength values.
11. Reporting Requirements
A complete ASTM D4562 test report should include:
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Adhesive identification and cure conditions
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Specimen material and surface preparation method
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Pin diameter and bond length used for calculations
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Test machine and fixture description
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Crosshead speed
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Maximum force and calculated shear strength for each specimen
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Average values and standard deviation
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Observed failure modes
12. Practical Considerations and Best Practices
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Ensure axial alignment to avoid bending loads
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Use consistent surface preparation procedures
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Verify fixture rigidity and clearance
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Control environmental conditions during cure and test
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Size load cells appropriately for the expected force range
13. Summary
ASTM D4562 provides a reliable and repeatable method for evaluating the shear strength of adhesives in cylindrical joints. When performed using properly prepared specimens, rigid compression fixtures, and a well-configured universal testing machine, the method delivers meaningful performance data directly applicable to real-world retaining and locking applications.
UniversalTestMachine.com supports laboratories and manufacturers with complete ASTM D4562 testing solutions, including universal testing machines, compression fixtures, and technical expertise to ensure accurate and repeatable adhesive shear testing.
