Rayco Fixtures

The collection carries Rayco Fixtures products organized across two product families and four thread standards. The two families are fixture kits (clamping accessories for CMMs and optical measuring systems) and fixture plates (the aluminum base reference surfaces those kits attach to). Within fixture kits, three clamping methods are offered: standard clamping kits (CK), magnetic clamping kits (MCK), and vacuum clamping kits (VCK) plus Vision Kits (VK) designed specifically for optical CMMs. All four families are available in M4, M6, M8, and 1/4-20 thread standards, and most kits come in two or three component-count tiers (A, B, and C). Fixture plates are available in metric sizes from 450mm to 750mm square and imperial sizes from 18"×18" to 28"×40", plus vertical plate (VP) configurations in both thread standards.

A CMM fixture kit is a modular collection of components such as standoffs, springs, cones, jackstands, clamps, and mounting hardware are used to hold workpieces in a stable, repeatable position on a CMM (coordinate measuring machine) surface plate or fixture plate during dimensional inspection. Without proper fixturing, a part resting unsupported or hand-held on a CMM table can shift or rock during measurement, producing readings that reflect part position rather than part geometry. Consistent, repeatable fixturing ensures every part in a batch is measured from the same orientation with the same contact condition, a prerequisite for valid statistical process control, meaningful part-to-part comparison, and defensible quality documentation. In regulated industries including aerospace (AS9100), automotive (IATF 16949), and medical devices (ISO 13485), documented, repeatable measurement setups are not optional.

The three clamping methods address different part materials, geometries, and inspection requirements. Standard clamping kits (CK) use mechanical components such as standoffs, springs, jackstands, and cone locators that physically support and locate the part through contact, suitable for virtually any material and geometry. Magnetic clamping kits (MCK) replace the spring-and-cone clamping mechanism with magnetic standoffs that hold ferrous steel and iron parts through magnetic attraction, enabling fast, tool-free workpiece changes without mechanical clamping hardware, particularly useful in high-throughput production inspection where cycle time per part is critical. Vacuum clamping kits (VCK) use suction cups, a vacuum pump, a manifold, and flexible hoses to hold non-ferrous, non-magnetic parts such as aluminum, plastics, ceramics, and glass through vacuum pressure, providing secure, non-marring fixturing without any contact force that could distort thin-walled or delicate parts.

Vision Kits are fixture kits designed specifically for use with optical CMMs and vision measuring systems like the Insize ISD-V Series and ISD-E Series also available on the site where the part must be held stably on a glass transmission stage and illuminated from below for contour and profile measurement. Standard fixture kits are optimized for tactile CMMs where the probe physically contacts the part; the same opaque standoffs and clamps used in a tactile CMM setup would block transmitted backlighting in an optical system. Vision Kit components are engineered for compatibility with the open-stage geometry and transmitted light requirements of optical CMMs, providing the right standoff heights, contact-point configurations, and stage clearances for vision measurement workflows. The RA-series Vision Kits (RA4, RA6, RA20) are available in B and C component-count tiers in M4, M6, and 1/4-20 thread standards.

Kit tier designates the total component count included in the set, with each step up adding more standoffs, springs, cones, suction cups, and accessories to extend the range of part geometries and fixturing configurations the kit can accommodate. Tier A kits (where offered) are the entry level, providing the minimum component count needed for straightforward fixturing setups like the R6-VCK-A contains 102 components and the R8-VCK-A contains 97 components. Tier B kits step up to approximately 108–141 components depending on the kit family, providing significantly more configuration flexibility for diverse part geometries and multi-part setups on a single plate. Tier C kits are the most comprehensive, reaching 149–163 components making it the right choice for quality labs that inspect a wide variety of parts and configurations across multiple programs, or that need to fixture multiple parts simultaneously on a large plate. The right tier depends on the variety and complexity of parts your inspection program covers.

Rayco Fixtures kits and plates are available in four thread standards: M4, M6, M8, and 1/4-20. The thread standard must match both the fixture plate's threaded hole pattern and the CMM's table mounting pattern. M4 and M6 are ISO metric standards common in European CMM platforms and metric optical measuring systems. M8 is a larger metric standard suited to heavier-duty fixturing on larger CMM tables. 1/4-20 is the UNC inch-standard thread common in North American CMM platforms. Mixing thread standards between a kit and a plate will result in components that will not thread into the plate holes confirming your CMM table or fixture plate's thread standard before selecting a kit is the most important configuration decision in the entire purchase. If you are unsure of your CMM's table thread standard.

Rayco Fixtures plates are precision-machined aluminum with a clear hard lube anodize finish and engraved axis grid coordinates for repeatable part positioning and documentation. Metric plates are available in three sizes 450mm×450mm (13mm thick), 600mm×600mm (13mm or 19mm thick), and 750mm×750mm (19mm thick) all with M6 or M8 threaded holes on 15mm centers. Imperial plates come in four sizes 18"×18" (0.50"), 24"×24" (0.50" or 0.75"), 28"×40" (0.75"), and 30"×30" (0.75") with 1/4-20 threaded holes on 0.50" centers. Vertical plates (VP series) are available in M8 (R8-500250-VP: 250mm×203mm face, 500mm tall) and 1/4-20 (R20-2010-VP: 10"×8" face, 20" tall) for workpieces that must be fixtured upright. The key selection parameters are plate size relative to your largest part or multi-part setup, thread standard, and whether flat or vertical orientation is needed.

Vertical plates like the R8-500250-VP and R20-2010-VP mount the fixture plate standing upright on the CMM table rather than lying flat, with threaded holes on the vertical face. This configuration is required for parts that must be measured in a vertical or side-presentation orientation for example, parts where the critical features are on the side face, parts with tall profiles that would tip or be unstable if laid flat, or multi-axis measurement setups where the CMM probe must approach the workpiece from a horizontal direction. Vertical fixturing is also standard practice for measuring hole patterns and profiles on the sides of large housings, brackets, and structural components that cannot be meaningfully inspected from a top-down probe approach only.

Components within the same thread standard are fully interchangeable across kit tiers and kit types. For example, M6 standoffs, springs, and cones from an R6-CK-B kit will thread directly into an R6-60060019-15 or R6-45045013-15 fixture plate, and M6 magnetic standoffs from an R6-MCK-B kit will work in the same plates. This means a quality lab that starts with a Tier B kit can expand its component inventory by adding Tier C components individually, or mix magnetic and standard clamping components on the same plate for complex fixturing setups that require different hold methods on different features of the same part. Components do not cross between M4, M6, M8, and 1/4-20 thread standards since the thread standard is the hard boundary for interchangeability. Vacuum kit accessories (suction cups, pump, manifold, hoses) are also specific to their kit series but work with any same-thread-standard plate.

All Rayco Fixtures orders ship free to the continental USA, backed by a best-price guarantee. A 30-day return policy and Affirm financing at checkout are available across the full lineup. Government agencies, defense contractors, and institutional quality labs can submit an RFQ through the dedicated Government RFQ page (DUNS: 13-715-2209, CAGE: 15F67). Fixture system selection involves interconnected decisions between clamping method, thread standard, kit tier, plate size, and whether vision or tactile CMM compatibility is required and the wrong combination results in components that don't fit the plate or the CMM table. Gustavo personally reviews every order and strongly encourages buyers to confirm their CMM platform's thread standard and table size before purchasing simply call or text 617-398-7852, Monday through Friday, 8am–5pm EST.