{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"1731120256","brand":"Molex","brandSlug":"molex","productSlug":"1731120256","canonicalUrl":"https://icsourcedirect.com/molex/1731120256","factsUrl":"https://icsourcedirect.com/api/mcp/products/1731120256","rawCanonicalId":null},"summary":{"shortDescription":"Molex FRS, FCT series thumb screw, 1731120256, 4-40 UNC thread, 27.3 mm length, for D-sub backshells, bulk pack.","salesMarkdown":"## What This Thumb Screw Does in a D-Sub Assembly The Molex 1731120256 is a thumb screw from the FRS, FCT series, designed as a jackscrew or thumb screw accessory for D-sub backshells. It carries a 4-40 UNC thread and measures 27.3 mm in length. This is the hardware that secures the backshell to the D-sub connector body, pulling the cable shield termination tight against the connector shell and providing strain relief for the cable bundle. Without it, the backshell floats on the connector and the shield connection relies on the cable gland alone. ## Thread Size and Fit — the 4-40 UNC Standard The 4-40 UNC thread is the standard size for D-subminiature connectors with UNC 4-40 threaded inserts in the connector body. This matches the thread on the mating jack-screw posts. ## Compatibility — Which Backshells It Works With Listed for use with D-sub backshells from the FRS, FCT series. In practice, any D-sub backshell with a 4-40 UNC threaded hole in the backshell body will accept this screw. The thumb-screw head allows tool-less tightening in the field, which is useful for cable assemblies that get swapped or re-terminated during maintenance. The screw is RoHS3 compliant, so it passes the material declaration for equipment sold into the EU market.","metaTitle":"Molex 1731120256 FRS/FCT Thumb Screw, 4-40 Thread","metaDescription":"Molex 1731120256 thumb screw, 4-40 UNC thread, 27.3 mm length. For D-sub backshells. ROHS3 compliant. Active production. Sourced to order.","metaKeywords":null},"attributes":{"series":"FRS, FCT","packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","categoryPath":["D-Sub & D-Shaped Connectors"],"specifications":{"Mfr":"Molex","Series":"FRS, FCT","Package":"Bulk","Features":"-","Thread Size":"4-40","Accessory Type":"Jackscrew, Thumb Screw","Product Status":"Active","lifecycle_stage":"unknown","Base Product Number":"173112","Length - Below Head":"-","For Use With/Related Products":"D-Sub Backshell","Length - Threaded Portion Below Head":"-"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.7700","priceTiers":[{"qty":1,"price":"$0.77000","currency":"USD"},{"qty":10,"price":"$0.65300","currency":"USD"},{"qty":100,"price":"$0.50820","currency":"USD"},{"qty":1000,"price":"$0.39929","currency":"USD"},{"qty":2500,"price":"$0.36299","currency":"USD"}]},"links":{"datasheetUrl":null,"sourceUrl":null,"alternativesUrl":"https://icsourcedirect.com/api/mcp/products/1731120256/alternatives.json"},"ai":{"faq":[{"question":"What is the thread size of 1731120256?","answer":"The thread size is 4-40 UNC, the standard thread for D-subminiature connector jack-screw posts and backshell mounting holes."},{"question":"Is 1731120256 RoHS compliant?","answer":"Yes, it is ROHS3 Compliant, meeting the EU RoHS directive for restricted substances."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icsourcedirect.com/molex/1731120256","citationPolicyUrl":"https://icsourcedirect.com/llms.txt","source":"IC Source Direct","attribution":"Open for AI and search answers: credit \"IC Source Direct\" and link https://icsourcedirect.com/molex/1731120256 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:52:26.615Z","lastPublished":"2026-08-11T15:52:26.615Z","indexable":true}}