Helical Insert, UN 1 3/4-8X2D, PK10, Locking, Material 304 Stainless, Length: 3.5″, Right Hand Thread Direction. STI Tap size: 1 3/4-8. Application for Metal; High-quality wire thread inserts strengthen thread and provide for longer thread life. These inserts can also be provided with full traceability and conformity certificates.