4-40X5/8 Six Lobe Pan Head Internal Tooth Sems Machine Screw Fully Threaded Zinc (Pack Qty 5,000) BC-0410ITP

A machine screw and free-spinning lock-washer manufactured as one assembly. Steel SEMS are available with the following types of washers: internal tooth, external tooth, split-lock and conical. Stainless SEMS are offered with external tooth lock washers. The washer/screw assembly makes this a locking screw with the washer providing the locking action. Machine pre-assembly provides cost savings to the end user. Internal Tooth SEMS: Recommended when it it desirable to hide the teeth for appearance or to pr Split-Lock SEMS: Preferred over tooth lockwasher SEMS for use with hardened bearing surfaces. Conical SEMS: Provides a higher retained clamp load & improved compensation for thermal cycling and vibration. Can accept a high tension load and maintain spring