What Is The Difference Between ‘Pitch’ and ‘Fin Gap’ in Heatsinks
Mar 27, 2025| In heat sink terminology, Pitch" and "Fin Gap" is often confused. Now let's come and have a look at the difference between 'Pitch' and 'Fin Gap'.
1. Fin Gap
- Definition: The clearance distance between two adjacent heat-dissipation fins (i.e., the actual airflow passage).
- Calculation: Refers only to the gap between fins, excluding the thickness of the fins themselves.
- Impact:
- Directly affects airflow resistance: A smaller gap increases airflow resistance, reducing cooling efficiency, while a larger gap may decrease the heat dissipation area.
- Influences dust resistance: Smaller gaps are prone to dust accumulation and clogging.
- Typical Range: Usually 1–3 mm, depending on thermal requirements and fan performance.
2. Pitch
- Definition: The 'center-to-center' distance between adjacent fins (i.e., the periodic length from the start of one fin to the start of the next).
- Calculation: Pitch = Fin Gap + Fin Thickness.
- Example: If the fin thickness is 0.5 mm and the fin gap is 2 mm, then Pitch = 2.5 mm.
- Impact:
- Reflects fin density: A smaller pitch increases the number of fins per unit length, maximizing the heat dissipation area.
- Relates to manufacturing constraints: Extremely small pitches may increase production complexity and cost.
3. Key Difference between 'Pitch' and 'Fin Gap'
| Single | 92*188 | 37*37*102 | 192PCS | 476PCS |
| King-Single | 107*203 | 37*37*117 | 180PCS | 420PCS |
| Double | 138*188 | 37*37*148 | 144PCS | 336PCS |
| Queen | 153*203 | 37*37*163 | 108PCS | 302PCS |
| King | 183*203 | 37*37*193 | 108PCS | 252PCS |
4. Application Scenario
- Optimizing Heat Dissipation:
- To maximize surface area (e.g., passive cooling), reduce pitch (but ensure sufficient fin gap to avoid airflow blockage).
- For forced-air cooling (e.g., CPU coolers), prioritize adequate fin gap to reduce noise and dust buildup.
- Design Formula:
Pitch= Fin Gap + Fin Thickness
Example
Assume a heat sink with:
- Fin Thickness = 0.3 mm
- Fin Gap = 1.2 mm
Then, Pitch = 1.2 + 0.3 = 1.5 mm.
This means every 1.5 mm cycle includes a 1.2 mm airflow channel and a 0.3 mm metal fin.
'Fin Gap' focuses on the airflow channel's physical space, while 'Pitch' is a structural parameter that includes fin thickness. Together, they determine a heat sink's efficiency, noise, and reliability.
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