"针入度试验" can be translated into English as "penetration test" (in the context of bitumen or asphalt testing) or more specifically as "needle penetration test" when emphasizing the use of a needle in the procedure.
In the field of road engineering or materials testing for bituminous materials, "penetration test" is a commonly accepted term. For example:
The penetration test is used to determine the consistency of bitumen.
A standard needle penetration test is carried out under specified conditions of temperature, load, and time.
If greater specificity is needed, "needle penetration test" can be used to clearly describe the method involving a needle.