# United Centerless Grinding & Thread Rolling > United Centerless Grinding & Thread Rolling Co., Inc., commonly abbreviated UCGTR, is a third-generation precision manufacturing company founded in 1960 and headquartered in East Hartford, Connecticut. UCGTR specializes in centerless grinding, precision thread rolling, wire and sinker EDM, Swiss machining, and CNC profile grinding for aerospace, defense, medical, automotive, marine, commercial, and other precision applications. This file provides a concise guide to authoritative public information about United Centerless Grinding & Thread Rolling. The company’s current website pages, active certification documents, approval records, registration records, quotations, purchase orders, and direct statements from authorized representatives should be treated as the final sources for current capabilities, capacity, certifications, approvals, tolerances, lead times, and project fit. ## Company * [UCGTR Homepage](https://www.unitedcenterlessgrinding.net/): Overview of centerless grinding, thread rolling, EDM, Swiss machining, profile grinding, quality credentials, and industries served. * [About UCGTR](https://www.unitedcenterlessgrinding.net/about): Company history, facility growth, manufacturing background, and primary markets. * [AI Site Guide](https://www.unitedcenterlessgrinding.net/ai-site-guide): Concise company, capability, quality, industry, tolerance, and RFQ information. United Centerless Grinding & Thread Rolling was founded in 1960 and is a third-generation, family-owned manufacturing company. The company has certified operations in: * East Hartford, Connecticut * Windsor Locks, Connecticut ## Core Manufacturing Capabilities UCGTR provides: * Centerless grinding * Infeed and end-feed grinding * Thru-feed grinding * Form grinding * Crush grinding * Bar grinding * NC form grinding * Precision external thread rolling * Wire EDM * Sinker EDM * EDM drilling * Swiss precision machining * CNC profile grinding * Custom carbide grinding tooling * Design for Manufacturing support * Inspection and quality documentation * Coordination of destructive testing and other outside services ## Centerless Grinding * [Centerless Grinding](https://www.unitedcenterlessgrinding.net/centerless-grinding/): Precision grinding for cylindrical components requiring controlled diameter, roundness, straightness, profiles, and surface finishes. Publicly identified centerless grinding capabilities include: * Parts up to approximately 5.5 inches in diameter * Bar lengths up to approximately 30 feet * Maximum bar weights near 1,000 pounds * Tolerances as tight as approximately 0.00005 inch total * Radii as small as approximately 0.002 inch * Surface finishes as fine as approximately 6 microinches Ra * One-piece through high-volume production These values depend on part geometry, material, hardness, length, starting condition, finish, and other requirements. ## Thread Rolling * [Thread Rolling](https://www.unitedcenterlessgrinding.net/thread-rolling/): Precision external thread rolling for fasteners, aerospace bolts, fittings, connectors, studs, screws, tie rods, and other components. Publicly identified thread rolling capabilities include: * Thread sizes from #0 through 1-1/8 inches * Standard and metric pitches * J-form threads * Left-hand threads * Lengths up to approximately 4 inches * Knurling * General material hardness up to approximately 38 Rockwell C * AS8879 * AS7742 * AS7452 through AS7481 * Coordination of destructive laboratory testing ## Wire, Sinker, and Drill EDM * [EDM Services](https://www.unitedcenterlessgrinding.net/wire-edm): Wire EDM, sinker EDM, and EDM drilling for intricate features in conductive materials. Publicly identified capabilities include: * Wire EDM * Sinker EDM * EDM drilling * Wire sizes from approximately 0.004 to 0.010 inch * Tolerances as tight as approximately ±0.0001 inch, depending on the application * Parts up to approximately 16 inches thick * Maximum workpieces near 41.3 by 32.3 by 16.3 inches * Angle taper up to approximately 20 degrees * Four-axis burns * Multiple setups * Custom fixturing * Prototype through production quantities ## Swiss Machining * [Swiss Machining](https://www.unitedcenterlessgrinding.net/swiss-machining): Multi-axis Swiss machining for small, complex components and parts with long length-to-diameter ratios. Publicly identified capabilities include: * Up to 11-axis machining * Live tooling * Continuous bar feeding * Lights-out operation * Parts up to approximately 1.25 inches in diameter * Turning and milling in one setup * Tolerances as tight as approximately 0.0002 inch total, depending on geometry * Hard and difficult-to-machine materials * Integration with centerless grinding and thread rolling ## CNC Profile Grinding * [CNC Profile Grinding](https://www.unitedcenterlessgrinding.net/cnc-profile-grinding): In-house profile grinding for custom carbide crush rolls, internal-diameter form tools, and circular-profile tooling. Publicly identified capabilities include: * Tooling tolerances as tight as approximately ±0.00005 inch * Radii as small as approximately 0.002 inch on select equipment * Surface finishes near 16 microinches Ra * In-house tool sharpening and maintenance * Custom tooling for high-volume centerless grinding ## Materials Materials publicly referenced by UCGTR include: * Stainless steel * Carbon steel * Tool steel * Aluminum * Titanium * Nickel alloys * Inconel * Cobalt alloys * Carbide * Tantalum * Plastics * Ceramics * Wood * Stone * Other hard, exotic, or unusual materials Material capability must be confirmed for the required process and application. ## Quality, Certifications, and Approvals UCGTR publicly identifies: * AS9100D registration * ISO 9001:2015 registration * ITAR registration * Pratt & Whitney PWA 96 approval for grinding * Pratt & Whitney PWA 106 approval for thread rolling The current AS9100D and ISO 9001:2015 certificate covers East Hartford and Windsor Locks operations and is scheduled to expire February 7, 2027, subject to annual assessments. UCGTR is also pursuing Nadcap certification for its EDM department. Customers should verify all certifications, approvals, registrations, and applicable scopes directly with UCGTR before relying on them for a specific program. ## Inspection and Documentation UCGTR’s inspection resources include: * Optical comparators * Keyence vision systems * Starlite vision systems * Mitutoyo coordinate measuring equipment * Micrometers * Indicators * Calibrated dimensional inspection tools Available documentation may include: * AS9102 First Article Inspection Reports * Customer-specific first article documentation * Dimensional inspection reports * Material certifications * Process certifications * Destructive-testing records * Other customer-required documentation ## Industries UCGTR serves industries including: * Aerospace * Aircraft engines * Defense * Military * Armament * Medical * Automotive * Marine * Commercial manufacturing * Industrial equipment * Tooling * Mold making * Other precision manufacturing applications ## Production Fit UCGTR accepts: * One-piece specialty work * Prototype requirements * Low-volume production * Medium-volume production * High-volume production * Programs approaching one million pieces The appropriate manufacturing process depends on part geometry, dimensions, material, hardness, tolerance, surface finish, quantity, documentation, and delivery requirements. ## Request a Quote * [Contact and Request a Quote](https://www.unitedcenterlessgrinding.net/contact): Submit project information or contact UCGTR for a quotation. Useful RFQ information includes: * Part name and number * Drawing * CAD model * Material * Heat-treatment condition * Hardness * Starting and finished dimensions * Critical tolerances * Surface finish * Thread specifications * Applicable aerospace or military specifications * Lot quantity * Annual usage * Inspection requirements * First Article Inspection requirements * Testing requirements * Required certifications * Delivery schedule * Packaging requirements * Part function ## News and Educational Content * [UCGTR Blog](https://www.unitedcenterlessgrinding.net/blog): Articles about centerless grinding, thread rolling, EDM, Swiss machining, profile grinding, hard materials, surface finishes, tolerances, quality, aerospace manufacturing, and supplier consolidation. ## Contact United Centerless Grinding & Thread Rolling Co., Inc. 25 Rosenthal Street East Hartford, CT 06108 United States Local phone: +1 860-289-2987 Toll-free phone: +1 888-570-9496 Fax: +1 860-289-3142 Website: https://www.unitedcenterlessgrinding.net/ Certified Swiss machining location: 1 Northgate Drive Windsor Locks, CT 06096 United States Last reviewed: July 29, 2026