.nb-desc details > summary { list-style: none; display: flex; justify-content: space-between; align-items: center; cursor: pointer; font-weight: 600; padding: 12px 0; border-top: 1px solid #e0e0e0; } .nb-desc details > summary::-webkit-details-marker { display: none; } .nb-desc details > summary::after { content: '▼'; font-size: 0.7em; opacity: 0.6; transition: transform 0.25s ease; flex-shrink: 0; margin-left: 8px; } .nb-desc details[open] > summary::after { transform: rotate(180deg); } .nb-desc details > div { padding: 8px 0 16px 0; } .nb-desc details:last-of-type { border-bottom: 1px solid #e0e0e0; } .nb-desc table { width: 100%; border-collapse: collapse; } .nb-desc td { padding: 8px 12px 8px 0; vertical-align: top; border-bottom: 1px solid #f0f0f0; } .nb-desc td:first-child { width: 40%; font-weight: 600; } A pre-packaged SEMS screw assortment covering the sizes most commonly used in domestic vehicle body, interior, and underhood attachment — SEMS screws have a free-spinning captive washer pre-assembled on the shank so the washer can't be lost, misaligned, or forgotten during installation. On a production line or a busy service bay, the captive washer eliminates a handling step and ensures every fastener arrives at the joint correctly assembled. What's Included SEMS screws — multiple sizes with pre-assembled captive external tooth or flat washers Multiple thread sizes and lengths covering common domestic vehicle body and trim applications Specifications Fastener type SEMS screws (screw with pre-assembled captive washer) Washer types External tooth lock washer and/or flat washer (pre-assembled) Application Domestic vehicle body, interior trim, and underhood attachment Supplier Auveco Best For Auto body and collision shops — SEMS screws are factory-standard fasteners throughout domestic vehicle bodies; a stocked assortment of common sizes means reassembly proceeds without separate screw-and-washer sourcing Fleet maintenance operations — routine panel and trim removals on domestic commercial vehicles use SEMS screws; the captive washer ensures correct reassembly even in tight access areas Restoration and reconditioning shops — original SEMS screws corrode and break; this assortment covers the range of sizes needed to reinstall body and trim components correctly Understanding SEMS Screws SEMS (an acronym derived from the manufacturing process: Screw and Externally applied washer on the Shank) are machine or thread-forming screws with a washer permanently captivated on the shank during production. The washer is free to spin — it doesn't rotate with the screw — but it cannot come off the shank before or during installation. The captive washer provides two benefits: assembly efficiency (one part to handle instead of two) and reliability (the washer is always present, always correctly positioned). External tooth lock washers on SEMS screws provide thread-locking and electrical grounding contact simultaneously, which is why they appear extensively in automotive electrical grounds and body panel bonding points. When replacing a SEMS screw, match the screw thread and length as well as the washer type (external tooth vs. flat) and OD. Questions? Contact us. Shipping & Ordering Ships within 1–2 business days from our warehouse Volume pricing available — save up to 20% when ordering 3 or more Reorder regularly? Ask us about a B2B account with custom pricing — contact us
