English to Spanish Tech/Engineering Petroleum Eng/Sci ensayos de calidad de grasas lubricantes

El texto es un manual de la ASTM, sobre ensayos de calidad para productos derivados del petróleo. En este caso, se trata de un ensayo para determinar si una grasa contiene partículas que puedan rayar el plástico. Contexto:

"ASTM D 1404, Test Method for Estimation of ***Deleterious Particles*** in Lubricating Grease, defines a deleterious particle as one which will scratch a polished plastic surface. [...]

With this method, the test material is placed between two clean, highly polished acrylic plastic plates held rigidly and parallel to each other in metal holders. The assembly is pressed together by squeezing the grease into a thin layer between the plastic plates. Any solid particles in the grease larger than the distance of separation of the plates and harder than the plastic will become imbedded in the opposing plastic surfaces."

Desde ya, muchas gracias.