What Is Pin-on-Disc?
The pin-on-disc test is a tribological test in which friction force and material loss are continuously monitored while a pin under a defined load traces a circular path sliding on a rotating disc surface.
Purpose of Pin-on-Disc
The purpose is to comparatively determine the coefficient of friction and wear rate of material pairs under controlled conditions.
Which Products Is Pin-on-Disc Applied To?
- Bearing and bushing materials
- Sert kaplamalar
- Ceramic components
- Lubricant formulations (lubricated test)
- Brake and clutch materials
In Which Sectors Is Pin-on-Disc Used?
Standards Related to Pin-on-Disc
- ASTM G99
- ISO 20808
- DIN 50324
Pin-on-Disc Conditions
- Normal load
- Constant load defined in the specification
- Sliding speed
- Constant speed calculated from disc rotation and track diameter
- Sliding distance
- Defined as total distance
- Environment
- Dry or lubricated; temperature and relative humidity are recorded
Equipment for Pin-on-Disc
- Pin-on-disc tribometer
- Friction-force measurement cell
- Precision balance
- Profilometer
- Temperature and humidity monitoring
Sample Requirements for Pin-on-Disc
- The disc surface must be polished to the defined roughness
- Pin geometry and material must conform to the standard
- The initial mass of both elements must be measured
- Generally at least three repetitions
Duration of Pin-on-Disc
It depends on the sliding distance. A typical test takes a few hours; long-distance tests can exceed one working day.
Pin-on-Disc Procedure
- 1The pin and disc surfaces are prepared and their masses are measured.
- 2Load, speed and total distance are set.
- 3The test is started; friction force is recorded continuously.
- 4The test is stopped once the defined distance is completed.
- 5Mass loss is measured and the wear-track profile is taken.
- 6The coefficient of friction and wear rate are calculated.
Pin-on-Disc Acceptance Criteria
The acceptance criterion is given in the specification as a maximum coefficient of friction or a maximum wear rate.
Evaluation of Results
The steady-state region of the friction-coefficient curve is taken as the basis. The running-in region is noted separately. Volume loss is calculated from the wear-track cross-sectional area.
Pin-on-Disc Report
- Standard applied
- Pin and disc materials, geometry
- Load, speed, distance and environment
- Friction-coefficient curve and steady-state value
- Wear rate and track profile
Accreditation
EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.
Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.
Scope and authorisationsRelated Regulations
- Material and lubricant specifications
Mekanik Testler — What Does This Testing Field Cover?
The section below describes the field that the Pin-on-Disc test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.
Mechanical testing measures how a material or a part behaves under force. The family ranges from static loading (tension, compression, bending) to time-dependent behaviour (fatigue, creep), and from hardness and wear to fracture toughness.
What these tests have in common is that the result is reported as a MATERIAL PROPERTY. Yield strength or hardness is not a conformity decision; it is numerical data against which the design and the product standard will compare. Mechanical test reports are therefore usually an input to an engineering decision rather than to a product approval — material selection, safety factor, life prediction.
The distinction between static and dynamic behaviour is the key to understanding the field. A part may appear entirely unstressed under a static load yet break under repeated loading; fatigue fracture occurs at stresses well below the yield strength and gives no warning. For rotating, vibrating or cyclically loaded parts, a tensile test alone is therefore not sufficient evidence.
Test conditions determine the result, and this is critical for the readability of the report: specimen geometry, loading rate, temperature, conditioning and the gripping arrangement. The same material gives different values under different conditions. In plastics the rate effect is very pronounced, in metals the temperature effect; in composites the specimen orientation changes the result entirely.
Hardness is the most misused measurement in the field. Because it is fast, close to non-destructive and inexpensive, it is often used in place of strength. Conversion tables from hardness to strength exist, but they are APPROXIMATE and depend on the material group; using them as the sole evidence in material acceptance is wrong.
The fracture mechanics side requires a specific competence. Fracture toughness and fatigue crack growth rate measurements make it possible to calculate how long a cracked structure will last; they are the basis of damage-tolerant design in fields such as pressure equipment, aircraft structures and pipelines.
Method groups in this field
Static tests
Tension, compression, bending, shear and torsion. Yield and tensile strength, elongation and modulus of elasticity are obtained.
Impact tests
Charpy and Izod notch impact; the brittle-to-ductile transition behaviour of the material is determined as a function of temperature.
Hardness
Brinell, Vickers, Rockwell, Shore and micro hardness. Valuable for surface treatment depth and local differences in strength.
Fatigue
Force- and strain-controlled axial fatigue, fatigue in bending; S-N curves and the endurance limit.
Creep and stress relaxation
Behaviour under long-term load at high temperature; decisive for boiler, turbine and pressure equipment materials.
Fracture mechanics
Plane-strain fracture toughness, the J integral, CTOD and fatigue crack growth rate.
Wear and friction
Taber and rotating drum abrasion, coefficient of friction measurements.
Commonly confused in this field
- Calculating strength from hardness is approximate; it cannot be used as the sole evidence in material acceptance.
- Adequate static strength does not demonstrate fatigue strength; a cyclically loaded part requires a separate test.
- If test rate and temperature are not reported, the result cannot be compared — especially for polymers and composites.
- A test specimen and the actual part may not give the same value; moulding orientation, weld lines and differences in surface treatment all have an effect.
- A strength value given for a composite without stating the specimen orientation is meaningless.
- ASTM and ISO counterparts measure the same quantity but use different specimen geometries; the results are not treated as directly equivalent.
Which decisions these results support
- Design verification and material selection
- Incoming material control and supplier approval
- Meeting the mechanical requirements of the product standard
- Failure analysis, life prediction and damage tolerance calculation
- Verifying heat treatment and surface treatment processes
Related Tests
Frequently Asked Questions About Pin-on-Disc
According to which standard is Pin-on-Disc made?
Pin-on-Disc is executed in scope ASTM G99, ISO 20808 and DIN 50324. The limit values and acceptance criteria to be applied are defined in the product standard; The version valid for your product is confirmed in writing at the offer stage.
Which products does Pin-on-Disc apply to?
Mainly applied to Bearing and bushing materials, Sert kaplamalar, Ceramic components, Lubricant formulations (lubricated test) and Brake and clutch materials. Whether your product is included in the scope is determined by examining its technical specifications and intended use.
Under what conditions is Pin-on-Disc done?
The determining parameters are: Normal load — Constant load defined in the specification, Sliding speed — Constant speed calculated from disc rotation and track diameter and Sliding distance — Defined as total distance. The full terms are in the "Test Conditions" section on the page and vary depending on the product standard.
What kind of sample is needed for Pin-on-Disc?
The disc surface must be polished to the defined roughness, Pin geometry and material must conform to the standard and The initial mass of both elements must be measured. The number of samples is determined according to the product standard and the scope to be reported.
How long does Pin-on-Disc take?
It depends on the sliding distance. A typical test takes a few hours; long-distance tests can exceed one working day. This duration belongs to the experiment itself; sample preparation, queuing and reporting are also evaluated. A realistic schedule for your product is given in the offer.
What is the Pin-on-Disc result called "appropriate"?
The acceptance criterion is given in the specification as a maximum coefficient of friction or a maximum wear rate.