4-40X1/4 Slotted Pan Internal Sems Machine Screw Fully Threaded Zinc (Pack Qty 10,000) BC-0404ISP by Shorpioen

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 | Steel Screws-- AISI 1022 or equivalent steel. -- Steel Washers-- Split-lock: SAE 1055-1065 carbon steel; Tooth-lock: SAE 1050-1065; Conical: SAE 1050. | Stainless Screws-- SAE 18-8 stainless steel or 410 martensitic stainless steel -- Stainless Washers-- Split-lock: SAE J405 302-305; Tooth-lock: SAE 410 stainless steel; Conical: 410 stainless steel.