{"$schema":"nativecad-dfm-pack/1","id":"tooling","title":"Tooling - fixture plates, jigs, workholding, gauges","sector":"tooling","version":"2026-09-03","summary":"Grid fixture plates, 3-2-1 locating, clamping, vise soft jaws, 1-2-3/2-4-6 blocks, drill jigs and bushings, go/no-go gauges, 3D-printed jigs, inspection and assembly fixtures, plus the materials, tolerances and tests a job-shop fixture is held to.","aliases":["fixture","jig","fixture plate","tooling plate","workholding","soft jaws","vise jaws","drill jig","gauge","go no-go","1-2-3 block","locating pin","clamp","modular fixture"],"crossSector":false,"size":"core","sources":[{"id":"carr-lane-handbook","title":"Carr Lane Manufacturing Co. — Jig and Fixture Handbook / Workholding Components Catalog","url":"https://www.carrlane.com/","accessed":"2026-09-03"},{"id":"mitee-bite-fixturing-guide","title":"Mitee-Bite Products — Fixturing Systems Catalog and Design Guide (dowel/tapped grid plates)","url":"https://www.miteebite.com/","accessed":"2026-09-03"},{"id":"renishaw-fixturing","title":"Renishaw — Modular Fixturing Systems (grid plate hole layout)","url":"https://www.renishaw.com/en/fixturing-systems--6015","accessed":"2026-09-03"},{"id":"kurt-workholding","title":"Kurt Workholding — Precision Vise Drawings and Specifications (DX6/D688 series)","url":"https://www.kurtworkholding.com/","accessed":"2026-09-03"},{"id":"mcmaster-123-block","title":"McMaster-Carr — Precision Ground 1-2-3 Blocks, dimensional drawing","url":"https://www.mcmaster.com/1-2-3-blocks/","accessed":"2026-09-03"},{"id":"iso-1938","title":"ISO 1938-1:2015 Geometrical product specifications — Plain limit gauges — Part 1: Gauges for workpieces with size tolerances","url":"https://www.iso.org/standard/61529.html","accessed":"2026-09-03"},{"id":"iso-286","title":"ISO 286-1:2010 ISO code system for tolerances on linear sizes","url":"https://www.iso.org/standard/45123.html","accessed":"2026-09-03"},{"id":"mic6-datasheet","title":"Cast aluminium tooling plate (MIC-6) technical data sheet — flatness, stress-relief and composition","accessed":"2026-09-03","note":"Manufacturer datasheet, exact vendor URL unconfirmed at time of writing"}],"entries":[{"id":"fixture-grid-pitch","kind":"dimension","tier":1,"title":"Modular fixture-plate grid pitch","summary":"Modular tooling plates (Mitee-Bite, Renishaw style) carry a hole grid on 25 mm (1 in) or 50 mm pitch, dowelled and tapped, so any subplate or clamp lands on a repeatable station without new drilling.","applies":["fixture plate","tooling plate","grid plate","modular fixture"],"value":{"options":[25,50],"unit":"mm"},"basis":"Mitee-Bite and Renishaw catalog grid-plate series standardize on 25 mm/1 in metric-inch-compatible pitch, 50 mm on larger plates","sources":["mitee-bite-fixturing-guide","renishaw-fixturing"],"tags":["grid","pitch","modular","fixture-plate"]},{"id":"dowel-tapped-alternation","kind":"feature","tier":1,"title":"Alternating dowel / tapped grid hole pattern","summary":"Grid-plate stations alternate a precision dowel hole (dia6 H7 or dia8 H7, for locating) with a tapped hole (M6 or M8, for clamping) so every other node locates and every other node fastens - never both in one hole.","applies":["fixture plate","tooling plate","grid plate"],"value":{"table":[{"role":"locate","dia":6,"fit":"H7"},{"role":"clamp","thread":"M6"},{"role":"locate","dia":8,"fit":"H7"},{"role":"clamp","thread":"M8"}],"unit":"mm"},"basis":"Renishaw/Mitee-Bite grid plates checkerboard dowel and tapped stations so a subplate can be both located and bolted from the same grid","sources":["mitee-bite-fixturing-guide","renishaw-fixturing"],"tags":["dowel","tapped","grid","alternation"],"see":["hardware/dowel-pin-holes"]},{"id":"fixture-plate-thickness","kind":"dimension","tier":1,"title":"Fixture / tooling plate thickness","summary":"General-purpose fixture and grid plates run 12-25 mm thick: 12-16 mm for light fixtures and soft-jaw carriers, 20-25 mm where tapped holes must hold clamp preload and dowel holes must resist tipping under cutting load.","applies":["fixture plate","tooling plate","subplate"],"value":{"min":12,"max":25,"typical":20,"unit":"mm"},"basis":"Carr Lane and Mitee-Bite catalog plate thicknesses balance tapped-hole engagement depth against added mass and cost","sources":["carr-lane-handbook","mitee-bite-fixturing-guide"],"tags":["plate","thickness"]},{"id":"mic6-flatness","kind":"tolerance","tier":1,"title":"MIC-6 cast tooling plate flatness","summary":"MIC-6 cast, stress-relieved aluminium tooling plate holds flatness within 0.15 mm over any 300 mm span as-cast, far tighter than rolled 6061 plate, which is why it is the default fixture-plate stock.","applies":["mic-6","tooling plate","fixture plate"],"value":{"max":0.15,"unit":"mm"},"basis":"Cast (not rolled) and stress-relieved before machining, so internal stress does not release and warp the plate after milling","sources":["mic6-datasheet"],"tags":["mic-6","flatness","tooling-plate"]},{"id":"three-two-one-principle","kind":"rule","tier":1,"title":"3-2-1 locating principle","summary":"A rigid body is fully located with 6 point contacts distributed 3-2-1: three points define the primary (largest) datum plane, two more define a secondary plane perpendicular to it, and one more a tertiary plane - removing all 6 degrees of freedom with the minimum contact.","applies":["fixture","jig","locating scheme"],"basis":"Kinematic locating theory (6 DOF = 6 constraints), the foundation of every jig-and-fixture handbook locating scheme","sources":["carr-lane-handbook"],"tags":["3-2-1","locating","datum","kinematic"]},{"id":"locating-pin-pair","kind":"feature","tier":1,"title":"Round + diamond locating pin pair","summary":"A 2-pin location uses one full round pin plus one diamond (relieved) pin on the second hole: the diamond pin's narrow flats absorb the hole-to-hole distance tolerance so the part is not over-constrained and does not bind going onto the pins.","applies":["fixture","jig","locating pin"],"basis":"A second round pin over-constrains two-hole location against normal hole-position tolerance; a diamond pin removes the redundant width constraint while still fixing rotation","sources":["carr-lane-handbook"],"tags":["locating-pin","diamond-pin","round-pin"]},{"id":"locating-pin-fit-clearance","kind":"tolerance","tier":1,"title":"Locating pin fit: hole H7, pin g6, 0.02-0.05 mm clearance","summary":"A removable locating pin is toleranced hole H7 / pin g6, giving 0.02-0.05 mm diametral clearance - loose enough to load and unload the part by hand, tight enough to hold the 0.01-0.02 mm repeatability a fixture is built for.","applies":["fixture","jig","locating pin"],"value":{"min":0.02,"max":0.05,"unit":"mm"},"basis":"ISO 286 H7/g6 sliding fit class, the standard running fit for a hand-loaded locating pin","sources":["iso-286"],"tags":["h7","g6","clearance","locating-pin"],"see":["hardware/press-fit-pin-interference"]},{"id":"locating-accuracy","kind":"tolerance","tier":1,"title":"Fixture locating repeatability","summary":"A precision machining or inspection fixture locates a part to within 0.01-0.02 mm from load to load - the number the pin fit, the locator wear and the clamping sequence are all budgeted against.","applies":["fixture","jig"],"value":{"min":0.01,"max":0.02,"unit":"mm"},"basis":"Typical repeatability target for a CNC or CMM fixture, well inside the part's own dimensional tolerance","sources":["carr-lane-handbook"],"tags":["repeatability","locating","accuracy"]},{"id":"toggle-clamp-holding-force","kind":"fastener","tier":1,"title":"Toggle / cam / strap clamp holding force","summary":"Manual toggle, cam and strap clamps used in fixturing are rated 100-2500 N holding force depending on size - small vertical toggles at the low end, heavy horizontal-hold-down toggles and screw-actuated strap clamps at the high end.","applies":["toggle clamp","cam clamp","strap clamp","clamp"],"value":{"min":100,"max":2500,"unit":"N"},"basis":"Manufacturer catalog holding-force ratings across the common toggle-clamp size range","sources":["carr-lane-handbook"],"tags":["clamp","toggle-clamp","holding-force"]},{"id":"clamp-force-vs-cutting-force","kind":"rule","tier":1,"title":"Clamp force must exceed cutting force with margin","summary":"Total clamping force normal to a cutting load should be at least 2-3x the peak cutting force component that could lift or slide the part, to hold position through chatter and interrupted cuts, not just under steady load.","applies":["fixture","clamp","workholding"],"value":{"min":2,"max":3,"unit":"ratio"},"basis":"Standard workholding safety-factor rule of thumb against milling/drilling thrust and tangential force","sources":["carr-lane-handbook"],"tags":["clamp-force","cutting-force","safety-factor"]},{"id":"kurt-vise-jaw-width","kind":"dimension","tier":1,"title":"Kurt 6 in vise jaw width","summary":"The Kurt 6 in machinist vise (DX6/D688 class) has a 152 mm (6 in) jaw width, the most common CNC-mill vise size and the reference dimension every 6 in soft-jaw blank is machined to fit.","applies":["vise","kurt vise","soft jaws"],"value":{"value":152,"unit":"mm"},"basis":"Kurt catalog jaw width for the 6 in vise family","sources":["kurt-workholding"],"tags":["vise","kurt","jaw-width"]},{"id":"soft-jaw-blank","kind":"dimension","tier":1,"title":"Soft jaw blank size for a 6 in vise","summary":"A pair of soft jaws for a 6 in vise starts as two 150 x 50 x 25 mm blanks (6061 or 1018), bolted onto the vise's jaw plates and then machined in place to the part's own profile - including any dowel-pin slot for repeat setups.","applies":["soft jaws","vise jaws","vise"],"value":{"table":[{"dim":"length","mm":150},{"dim":"height","mm":50},{"dim":"thickness","mm":25}],"unit":"mm"},"basis":"Standard soft-jaw blank size matched to the Kurt 6 in vise jaw width","sources":["kurt-workholding"],"tags":["soft-jaws","blank","vise"]},{"id":"vise-jaw-bolt-pattern","kind":"fastener","tier":1,"title":"Soft jaw mounting bolt pattern (Kurt 6 in)","summary":"Kurt 6 in vise soft jaws bolt on with 3 x half-13 UNC cap screws on a 114.3 mm (4.5 in) bolt spacing - the standard hole pattern soft-jaw blanks are pre-drilled to.","applies":["soft jaws","vise jaws","kurt vise"],"value":{"table":[{"count":3,"thread":"1/2-13 UNC","spacing_mm":114.3}]},"basis":"Kurt catalog jaw-mounting hole pattern for the 6 in vise family","sources":["kurt-workholding"],"tags":["soft-jaws","bolt-pattern","kurt"]},{"id":"123-block-dims","kind":"dimension","tier":1,"title":"1-2-3 block dimensions","summary":"A precision 1-2-3 block measures 1 x 2 x 3 in (25.4 x 50.8 x 76.2 mm), ground square and parallel on all faces to within microns, used as a locating riser, angle reference or clamping spacer.","applies":["1-2-3 block","workholding","setup block"],"value":{"table":[{"dim":"x","mm":25.4},{"dim":"y","mm":50.8},{"dim":"z","mm":76.2}]},"basis":"Defining dimension of the 1-2-3 block: 1, 2 and 3 inches on a side","sources":["mcmaster-123-block"],"tags":["1-2-3-block","setup-block"]},{"id":"jig-plate-thickness-rule","kind":"rule","tier":1,"title":"Drill jig plate thickness vs. drill diameter","summary":"A drill jig plate is made 1.5-2x the drill diameter thick under the bushing bore, enough to keep the bushing supported and the drill guided straight without the plate becoming needlessly heavy.","applies":["drill jig","jig plate"],"value":{"min":1.5,"max":2,"unit":"ratio"},"basis":"Standard drill-jig design rule balancing bushing support against jig weight and cost","sources":["carr-lane-handbook"],"tags":["jig-plate","thickness","drill-bushing"]},{"id":"gauge-tolerance-iso1938","kind":"tolerance","tier":1,"title":"Gauge manufacturing tolerance (ISO 1938)","summary":"ISO 1938 sizes a go/no-go gauge's own manufacturing tolerance at roughly 10% of the part tolerance it inspects, split as gauge-maker tolerance plus wear allowance, so the gauge itself never consumes a meaningful share of the part's tolerance band.","applies":["gauge","go no-go","ring gauge","plug gauge"],"value":{"typical":10,"unit":"%"},"basis":"ISO 1938-1 gauge tolerance grades (GG/G-class) sized as a fraction of the workpiece tolerance","sources":["iso-1938"],"tags":["gauge","tolerance","iso-1938"]},{"id":"fixture-tolerance-critical","kind":"tolerance","tier":1,"title":"Fixture tolerance on locating features","summary":"Locating features on a fixture or jig - pin holes, datum pads, bushing bores - are held to +/-0.01-0.02 mm; everything else on the same plate (mounting holes, clearance pockets, edges) can run at a much looser +/-0.1 mm.","applies":["fixture","jig","fixture plate"],"value":{"min":0.01,"max":0.02,"unit":"mm"},"basis":"Locating features drive the fixture's repeatability budget directly; non-critical features do not","sources":["carr-lane-handbook"],"tags":["tolerance","locating","critical"]},{"id":"material-6061-t6","kind":"material","tier":1,"title":"6061-T6 aluminium for fixture bodies and soft jaws","summary":"6061-T6 (yield approx 276 MPa, density 2.70 g/cm3) is the default fixture-body and soft-jaw material: machines cleanly, holds a tapped hole well, and is light enough for a fixture an operator lifts by hand.","applies":["fixture","soft jaws","fixture plate"],"value":{"table":[{"property":"yield","value":276,"unit":"MPa"},{"property":"density","value":2.7,"unit":"g/cm3"}]},"basis":"General-purpose 6061-T6 mechanical properties, the standard aluminium fixture-component alloy","sources":["carr-lane-handbook"],"tags":["6061","aluminium","material"]},{"id":"material-1018","kind":"material","tier":1,"title":"1018 mild steel for jaws, locators and jig plates","summary":"1018 cold-rolled steel (yield approx 370 MPa, density 7.87 g/cm3) is the default steel for soft jaws, locators and jig plates needing more wear resistance and stiffness than aluminium but no hardening - it also case-hardens well where a wear surface is added later.","applies":["soft jaws","jig plate","locator"],"value":{"table":[{"property":"yield","value":370,"unit":"MPa"},{"property":"density","value":7.87,"unit":"g/cm3"}]},"basis":"General-purpose 1018 mild steel mechanical properties","sources":["carr-lane-handbook"],"tags":["1018","steel","material"]},{"id":"material-mic6","kind":"material","tier":1,"title":"MIC-6 cast tooling plate","summary":"MIC-6 is a cast, stress-relieved 5-series-like aluminium tooling plate (density approx 2.70 g/cm3) sold pre-flattened to 0.15 mm/300 mm - the default stock for fixture and grid plates over rolled 6061 wherever flatness matters more than raw strength.","applies":["fixture plate","tooling plate","grid plate"],"value":{"table":[{"property":"density","value":2.7,"unit":"g/cm3"},{"property":"flatness","value":0.15,"unit":"mm/300mm"}]},"basis":"MIC-6 datasheet: cast and stress-relieved for flatness stability, not for peak strength","sources":["mic6-datasheet"],"tags":["mic-6","tooling-plate","material"]}]}