"管脚号码" can be translated as "pin number" or "pin designation" in English.
"Pin number" is a straightforward and commonly used term to refer to the identifying number assigned to each pin on an electronic component or connector.
"Pin designation" is also accurate, as it emphasizes the specific identification or naming of each pin, which is crucial in electronic design and troubleshooting.
In most contexts, especially in technical documentation and engineering discussions, "pin number" would be the more commonly chosen expression.