scarf cut dril.

[MashaTs]

Пожалуйста, помогите перевести: scarf cut
Position the scarf cut in the first Back-Up Ring 90 from the scarf Retainer. Similarly, position the scarf cut in the second Back-Up Ring 90 from the scarf cut in the first Back-Up Ring.
контекст: инструкция по сборке пакеров
Спасибо!