{"product_id":"spi-21-237-3-radius-button-contact-point-dial-indicator","title":"Spi 21-237-3 Radius Button Contact Point Dial Indicator","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe SPI 21-237-3 is a radius button contact point designed for use with dial indicators in precision measurement applications. Machined from black oxide steel, this contact point features a 4-48 thread size and a 3\/4-inch diameter button face. The contact point length is 0.25 inches, conforming to AGD Group 1 industry standards. It is the type of replacement or supplemental contact point that metrology technicians, machinists, and quality control inspectors reach for when switching measurement setups or replacing worn contact surfaces on their dial indicators.\u003c\/p\u003e\n\u003cp\u003eThis contact point is suited for shop floor, tool room, and inspection room environments where dial indicators are used for surface measurement, runout checks, bore gauging, and fixture setups. The radius button profile distributes contact load evenly across curved or flat workpiece surfaces, reducing the risk of surface marking and improving measurement consistency across repeated readings. Its compact size and standard thread make it a practical addition to any precision measurement kit.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eRadius button contact style for consistent contact on flat and curved surfaces\u003c\/li\u003e\n  \u003cli\u003eBlack oxide steel construction for durability and corrosion resistance\u003c\/li\u003e\n  \u003cli\u003e4-48 thread size compatible with AGD Group 1 dial indicators\u003c\/li\u003e\n  \u003cli\u003e3\/4-inch diameter button face for broad contact coverage\u003c\/li\u003e\n  \u003cli\u003e0.25-inch contact point length for standard reach applications\u003c\/li\u003e\n  \u003cli\u003eMeets AGD Group 1 industry designation standards\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eDesigned for use with dial indicators requiring a 4-48 threaded contact point, conforming to AGD Group 1 specifications.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eContact point replacement is typically performed by machinists or metrology technicians. Before swapping contact points, remove the dial indicator from the fixture and ensure it is not under spring tension from the measuring spindle. Thread the contact point in by hand until snug, then tighten carefully to avoid cross-threading the fine 4-48 threads. Overtightening can damage the spindle threads and affect indicator accuracy.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eContact Point Style\u003c\/strong\u003e: Radius Button\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePoint Material\u003c\/strong\u003e: Black Oxide Steel\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThread Size\u003c\/strong\u003e: 4-48\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eContact Point Length\u003c\/strong\u003e: 0.25 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eButton Diameter\u003c\/strong\u003e: 3\/4 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eIndustry Designation\u003c\/strong\u003e: AGD Group 1\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFor Use With\u003c\/strong\u003e: Dial Indicators\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 0.1 pounds\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eStandard Information\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBrand\u003c\/strong\u003e: SPI\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: 21-237-3\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"SPIROTHERM","offers":[{"title":"Default Title","offer_id":51695952855346,"sku":"21-237-3","price":16.4,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/57e7073a7161fe9c1961d17431387fd2.jpg?v=1788339592","url":"https:\/\/voomisupply.com\/products\/spi-21-237-3-radius-button-contact-point-dial-indicator","provider":"Voomi Supply","version":"1.0","type":"link"}