{"$schema":"nativecad-dfm-pack/1","id":"jewellery-wearables","title":"Jewellery & wearables — rings, pendants, bracelets, watches, glasses","sector":"jewellery-wearables","version":"2026-09-04","summary":"Ring sizing (ISO 8653 and US/UK), band and bezel dimensions, prong and bezel settings, bangle/bracelet/pendant-bail sizing, watch case and strap dimensions, eyeglass frame box-system numbers, casting/DMLS processes, metal densities and the nickel-release, retention and drop tests jewellery and wearables are held to.","aliases":["ring","signet ring","wedding band","bracelet","bangle","cuff","pendant","necklace","earring","stud earring","watch case","watch strap","lug","glasses","eyeglass frame","sunglasses","jewelry","jewellery","brooch","cufflink","charm","bail"],"crossSector":false,"size":"standard","sources":[{"id":"iso-8653","title":"ISO 8653:2016 Ring-sizes","url":"https://www.iso.org/standard/65408.html","accessed":"2026-09-04"},{"id":"en-1811","title":"EN 1811:2023 Nickel release test method","url":"https://standards.iteh.ai/catalog/standards/cen/6692f2c9-c4b6-4539-a4d3-17611e1acdbc/en-1811-2023","accessed":"2026-09-04"},{"id":"iso-12870","title":"ISO 12870 Spectacle frames — requirements/tests","url":"https://www.iso.org/search.html?q=ISO%2012870","accessed":"2026-09-04"},{"id":"iso-8624","title":"ISO 8624 Spectacle frames — box system","url":"https://www.iso.org/search.html?q=ISO%208624","accessed":"2026-09-04"},{"id":"astm-f136","title":"ASTM F136 Ti-6Al-4V ELI implant alloy","url":"https://www.astm.org/f0136-13r21.html","accessed":"2026-09-04"},{"id":"astm-f138","title":"ASTM F138 316L implant stainless","url":"https://www.astm.org/f0138-19.html","accessed":"2026-09-04"},{"id":"materialise-gold-guide","title":"Materialise gold lost-wax casting guide","url":"https://www.materialise.com/en/academy/industrial/design-am/gold","accessed":"2026-09-04"},{"id":"ganoksin-casting","title":"Ganoksin — casting shrinkage/shop practice","url":"https://orchid.ganoksin.com/t/casting-shrinkage/48368","accessed":"2026-09-04"},{"id":"dmls-jewelry-guide","title":"i.materialise gold DMLS design guide","url":"https://i.materialise.com/en/3d-printing-materials/gold/design-guide","accessed":"2026-09-04"},{"id":"nihs-spring-bar","title":"NIHS 37-01 spring-bar diameters","url":"https://pompe-de-montre.com/en/content/16-measuring-watch-spring-bar","accessed":"2026-09-04"},{"id":"watch-lug-guide","title":"Watch lug-width sizing convention","url":"https://www.hewore.com/watch-lug-width-guide/","accessed":"2026-09-04"},{"id":"oura-ring-5","title":"Oura Ring 5 dimensions/battery","url":"https://ouraring.com/blog/introducing-oura-ring-5/","accessed":"2026-09-04"},{"id":"galaxy-ring-wiki","title":"Samsung Galaxy Ring dimensions","url":"https://en.wikipedia.org/wiki/Samsung_Galaxy_Ring","accessed":"2026-09-04"},{"id":"gia-diamond-sizes","title":"GIA diamond mm-to-carat chart","url":"https://www.gia.edu/gia-news-research/diamond-size-chart","accessed":"2026-09-04"},{"id":"density-reference","title":"Metal alloy density reference","url":"https://www.engineeringtoolbox.com/metal-alloys-densities-d_50.html","accessed":"2026-09-04"}],"entries":[{"id":"ring-size-definition-iso8653","kind":"standard","tier":2,"title":"Ring size is defined by inner circumference (ISO 8653)","summary":"ISO 8653 defines ring size as the inner circumference in mm, spanning roughly 40-76 mm for adult rings; every US/UK/EU size table is a relabelling of that one circumference number.","applies":["ring","signet ring","wedding band"],"basis":"ISO 8653 measures and designates ring size by internal circumference, not diameter, because a mandrel gauges circumference directly","sources":["iso-8653"],"tags":["ring","sizing","standard"]},{"id":"ring-size-us-uk-table","kind":"dimension","tier":1,"title":"US/UK ring size to inner diameter and circumference","summary":"US size 7 (UK N, EU 54) = 17.3 mm inner diameter / 54.4 mm circumference; each US half-size steps about 0.4 mm in diameter, e.g. US 6 = 16.5 mm ID, US 8 = 18.1 mm ID.","applies":["ring","signet ring","wedding band"],"value":{"table":[{"usSize":5,"idMm":15.7,"circumferenceMm":49.3},{"usSize":6,"idMm":16.5,"circumferenceMm":51.9},{"usSize":7,"idMm":17.3,"circumferenceMm":54.4},{"usSize":8,"idMm":18.1,"circumferenceMm":57},{"usSize":9,"idMm":18.9,"circumferenceMm":59.5},{"usSize":10,"idMm":19.8,"circumferenceMm":62.1}],"unit":"mm"},"basis":"ISO 8653 circumference table cross-referenced to the US/UK jeweller sizing convention","sources":["iso-8653"],"tags":["ring","sizing","us","uk"]},{"id":"band-width-range","kind":"dimension","tier":1,"title":"Ring band width","summary":"A ring band runs 2-8 mm wide (axial length along the finger); 2-3 mm reads as a stacking/eternity band, 5-6 mm as a standard wedding band, 7-8 mm as a chunky signet or men's band.","applies":["ring","wedding band","signet ring"],"value":{"min":2,"max":8,"typical":5,"unit":"mm"},"basis":"Common jeweller band-width range balancing comfort against visual weight for the stated ring classes","sources":["iso-8653"],"tags":["ring","band","width"]},{"id":"band-thickness-by-process","kind":"dimension","tier":1,"title":"Ring band radial thickness by process","summary":"Size a band's radial (wall) thickness at >=1.2 mm for cast gold, >=1.5 mm for cast/fabricated silver, and >=2 mm for a 3D-printed (resin-to-cast or DMLS) band, since each process's own minimum-section floor is what actually limits it.","applies":["ring","wedding band","signet ring"],"value":{"table":[{"process":"cast-gold","minMm":1.2},{"process":"cast-silver","minMm":1.5},{"process":"printed","minMm":2}],"unit":"mm"},"basis":"Gold's higher density and fluidity lets a cast band run thinner than silver at the same strength; a printed/print-and-cast band needs the extra margin the additive process's own minimum wall imposes","sources":["materialise-gold-guide","ganoksin-casting"],"tags":["ring","band","thickness","wall"]},{"id":"comfort-fit-inner-radius","kind":"rule","tier":1,"title":"Comfort-fit inner profile","summary":"A comfort-fit band rounds its inner bore to a radius roughly equal to the band's own radial thickness (1.2-2 mm), domed rather than flat, so the ring rocks past a knuckle instead of catching its full flat width on the skin.","applies":["ring","wedding band"],"value":{"min":1.2,"max":2,"unit":"mm"},"basis":"A domed inner profile reduces the ring's effective bearing width against the finger to roughly its thickness rather than its full band width, which is what a wearer feels as comfort fit","sources":["iso-8653"],"tags":["ring","comfort-fit","ergonomics"]},{"id":"prong-setting-basics","kind":"feature","tier":1,"title":"Prong count and prong-tip sizing for a stone setting","summary":"Use 4 prongs for a square/princess stone and 6 prongs for a round stone >=5 mm; each prong tip runs 0.8-1.2 mm square before it is filed down over the stone's girdle, thick enough to hold but thin enough not to hide the stone.","applies":["ring","pendant","prong setting"],"value":{"min":0.8,"max":1.2,"unit":"mm"},"basis":"Fewer, wider prongs suit a squared stone's flat girdle edges; a round stone's continuous girdle is held more securely by more, narrower prongs distributing load evenly","sources":["gia-diamond-sizes"],"tags":["ring","prong","setting","stone"]},{"id":"stone-size-mm-to-carat","kind":"dimension","tier":2,"title":"Round stone diameter to carat weight","summary":"A round-brilliant stone's carat weight tracks its diameter roughly as: 4.1 mm = 0.25 ct, 5.2 mm = 0.5 ct, 6.5 mm = 1 ct, 8.2 mm = 2 ct — use the mm figure to size the setting seat, not the carat.","applies":["ring","pendant","prong setting","bezel setting"],"value":{"table":[{"carat":0.25,"diameterMm":4.1},{"carat":0.5,"diameterMm":5.2},{"carat":1,"diameterMm":6.5},{"carat":2,"diameterMm":8.2}],"unit":"mm"},"basis":"Round-brilliant proportions relate carat weight to diameter through the stone's fixed depth-to-diameter ratio; the geometry that must be modelled is the diameter, not the weight","sources":["gia-diamond-sizes"],"tags":["stone","diamond","carat","sizing"]},{"id":"bezel-wall-thickness","kind":"dimension","tier":1,"title":"Bezel setting wall thickness","summary":"A metal bezel wrapping a stone's girdle runs 0.5-0.8 mm thick before burnishing over the stone; thinner tears when pushed over the girdle, thicker looks heavy and needs more force to set.","applies":["ring","pendant","bezel setting"],"value":{"min":0.5,"max":0.8,"unit":"mm"},"basis":"The bezel wall must be thin enough to burnish (cold-flow) over the stone's girdle by hand or with a bezel roller, but thick enough not to split while doing so","sources":["materialise-gold-guide"],"tags":["bezel","setting","wall"]},{"id":"bangle-id-oval","kind":"dimension","tier":1,"title":"Bangle inner diameter, oval opening","summary":"A rigid bangle needs a 60-70 mm oval inner opening (measured across the long axis, ~5-8 mm narrower on the short axis) to pass over an adult hand; a hinged bangle can drop the long axis toward 55 mm.","applies":["bangle","bracelet"],"value":{"min":60,"max":70,"typical":65,"unit":"mm"},"basis":"The oval opening must clear the widest part of an adult hand (the metacarpals) on the long axis while sitting close on the wrist once past the knuckles","sources":["iso-8653"],"tags":["bangle","sizing","oval"]},{"id":"bracelet-length-range","kind":"dimension","tier":1,"title":"Chain/flexible bracelet length","summary":"A flexible chain or bead bracelet runs 170-190 mm finished length for an adult wrist, plus 20-40 mm of clasp/extender adjustment; a men's bracelet sits at the upper end, a petite/child size below 170 mm.","applies":["bracelet","cuff"],"value":{"min":170,"max":190,"typical":180,"unit":"mm"},"basis":"Standard adult wrist circumference range plus the drape allowance a chain or bead bracelet needs to sit rather than bind","sources":["iso-8653"],"tags":["bracelet","sizing","length"]},{"id":"earring-post-dimensions","kind":"dimension","tier":1,"title":"Stud earring post diameter and length","summary":"A stud earring post runs 0.8 mm diameter x 10 mm long, sized to pass a standard pierced lobe and take a friction (butterfly) back with 2-4 mm of travel before it seats.","applies":["earring","stud earring"],"value":{"table":[{"param":"diameter","value":0.8},{"param":"length","value":10}],"unit":"mm"},"basis":"0.8 mm is the de-facto standard post gauge sized to a standard ear-piercing gun/needle bore, with 10 mm long enough to clear most lobe thicknesses plus the butterfly back","sources":["en-1811"],"tags":["earring","post","butterfly-back"]},{"id":"pendant-bail-clearance-rule","kind":"rule","tier":1,"title":"Pendant bail inner diameter vs chain gauge","summary":"Size a pendant bail's inner diameter to at least the chain's wire diameter plus 1 mm, so the chain articulates freely through the bail instead of binding or wearing a flat spot into the link.","applies":["pendant","bail","charm","necklace"],"value":{"min":1,"unit":"mm","note":"bail ID >= chain wire diameter + 1mm"},"basis":"A bail sized only to the chain's own diameter binds under normal articulation; the 1 mm margin is what lets the chain pivot instead of dragging metal-on-metal at one contact line","sources":["iso-8653"],"tags":["pendant","bail","chain","clearance"]},{"id":"watch-case-lug-width","kind":"dimension","tier":1,"title":"Watch case lug width","summary":"Watch straps come in 18, 20 or 22 mm lug width, matching the gap between the case's lug horns; 20 mm is the most common size across men's watches, with 18 mm skewing smaller/women's and 22-24 mm sport/diver cases.","applies":["watch case","watch strap","lug"],"value":{"options":[18,20,22,24],"unit":"mm"},"basis":"Industry lug-width convention that a strap and its spring bars must match to fit a given case","sources":["watch-lug-guide"],"tags":["watch","lug","strap","sizing"]},{"id":"watch-case-diameter-range","kind":"dimension","tier":1,"title":"Watch case diameter","summary":"A wristwatch case runs 36-44 mm in diameter (excluding crown), with 40-42 mm the most common men's size and 36-38 mm reading as a smaller/unisex case; the case diameter also sets the lug-to-lug envelope for wrist fit.","applies":["watch case"],"value":{"min":36,"max":44,"typical":40,"unit":"mm"},"basis":"Common modern wristwatch case-diameter range across men's and unisex sport/dress designs","sources":["watch-lug-guide"],"tags":["watch","case","diameter"]},{"id":"watch-spring-bar-hole","kind":"dimension","tier":1,"title":"Spring bar hole diameter in a lug","summary":"Bore the spring-bar hole through each lug at 1.2-1.5 mm diameter (standard spring bars run 1.0/1.2/1.3/1.5/1.8 mm), with a +-0.2 mm functional tolerance so the bar seats without slop or binding.","applies":["watch case","lug"],"value":{"min":1.2,"max":1.5,"unit":"mm"},"basis":"Spring bars are made in a small set of standard diameters; the lug hole must match one of them within a tight functional tolerance to hold the bar under spring load","sources":["nihs-spring-bar"],"tags":["watch","spring-bar","lug","hole"]},{"id":"glasses-box-system","kind":"dimension","tier":1,"title":"Eyeglass frame box-system callout (e.g. 52-18-140)","summary":"A frame is specified as lens-width–bridge–temple in mm, e.g. 52-18-140: 52 mm horizontal lens width, 18 mm bridge gap between lenses, 140 mm temple arm length from hinge to tip.","applies":["glasses","eyeglass frame","sunglasses"],"value":{"table":[{"param":"lens-width","typical":52},{"param":"bridge","typical":18},{"param":"temple","typical":140}],"unit":"mm"},"basis":"ISO 8624 box (boxing) system measures each lens as if boxed in a rectangle, giving three numbers that fully describe a frame's fit envelope","sources":["iso-8624"],"tags":["glasses","box-system","sizing"]},{"id":"glasses-hinge-screw","kind":"dimension","tier":1,"title":"Eyeglass hinge screw diameter","summary":"A spectacle hinge barrel takes a 1.2-1.6 mm screw through 2-3 knuckles; undersize and the hinge racks loose in weeks, oversize and the barrel wall splits on tightening.","applies":["glasses","eyeglass frame"],"value":{"min":1.2,"max":1.6,"unit":"mm"},"basis":"Standard spectacle-hinge screw gauge sized to the thin metal or acetate barrel wall a temple hinge is built into","sources":["iso-12870"],"tags":["glasses","hinge","screw"]},{"id":"glasses-pantoscopic-tilt","kind":"rule","tier":1,"title":"Pantoscopic tilt of the lens plane","summary":"Tilt the lens plane 8-12 degrees forward at the bottom (pantoscopic tilt) relative to vertical, so the lens sits roughly perpendicular to the wearer's downward gaze rather than straight-on.","applies":["glasses","eyeglass frame","sunglasses"],"value":{"min":8,"max":12,"unit":"deg"},"basis":"Matching the lens plane to habitual downward gaze angle reduces off-axis optical distortion for progressive and single-vision lenses alike","sources":["iso-12870"],"tags":["glasses","tilt","ergonomics"]},{"id":"casting-min-wall-no-voids","kind":"rule","tier":1,"title":"Lost-wax casting minimum wall and enclosed voids","summary":"Keep every cast section >=0.6 mm and never fully enclose a void: the investment plaster fills every internal cavity during burnout and cannot be removed from a sealed pocket, so a hollow form needs a vent/access hole before casting.","applies":["ring","pendant","casting"],"value":{"min":0.6,"unit":"mm"},"basis":"Below ~0.6 mm the wax pattern itself is too fragile to invest and the molten metal freezes before filling the section; a sealed cavity traps investment that cannot be devested afterward","sources":["materialise-gold-guide","ganoksin-casting"],"tags":["casting","lost-wax","wall","void"]},{"id":"casting-shrinkage-sprue","kind":"process","tier":2,"title":"Lost-wax casting shrinkage and sprue sizing","summary":"Allow 1-2% linear shrinkage from wax pattern to cast gold/silver part, and size the sprue at roughly 0.5-1x the part's thickest section so metal keeps feeding the casting as it solidifies instead of freezing off early.","applies":["ring","pendant","casting"],"value":{"min":1,"max":2,"unit":"%"},"basis":"Metal shrinks more than wax on cooling; an undersized sprue freezes before the thick section behind it has fed, leaving a shrinkage porosity void","sources":["ganoksin-casting"],"tags":["casting","shrinkage","sprue"]},{"id":"nickel-release-en1811","kind":"test","tier":1,"title":"Nickel release test for skin-contact jewellery (EN 1811)","summary":"EN 1811 limits nickel release to 0.5 ug/cm2/week for rings, bracelets and watch cases, and 0.2 ug/cm2/week for a post inserted into a piercing; failing it means re-specifying the alloy (nickel-free white gold, titanium, 316L), not changing geometry.","applies":["ring","earring","bracelet","watch case"],"value":{"min":0.2,"max":0.5,"unit":"ratio","note":"ug/cm2/week; 0.2 for pierced posts, 0.5 for general skin-contact"},"basis":"EN 1811 sets the EU REACH nickel-release migration limit, tested by immersion in artificial sweat solution, tighter for articles inserted into a piercing than for general skin contact","sources":["en-1811"],"tags":["test","nickel","hypoallergenic","en1811"]},{"id":"clasp-jump-ring-wire-gauge","kind":"dimension","tier":2,"title":"Jump ring and clasp wire gauge by chain weight","summary":"Size jump rings at 0.6-0.8 mm wire for a fine necklace/bracelet chain, 0.8-1.0 mm for a medium chain, and 1.0-1.2 mm for a heavy curb or bag chain, with the jump ring's own ID at least 1.5x the wire it closes onto.","applies":["clasp","jump ring","bracelet","necklace"],"value":{"table":[{"chainClass":"fine","wireMm":0.7},{"chainClass":"medium","wireMm":0.9},{"chainClass":"heavy","wireMm":1.1}],"unit":"mm"},"basis":"A jump ring's wire must be stiff enough not to fatigue-open under repeated clasp cycling, scaled to the chain load it carries","sources":["iso-8653"],"tags":["jump-ring","clasp","wire-gauge"]},{"id":"clasp-type-sizing","kind":"feature","tier":2,"title":"Common clasp types and their footprint","summary":"A lobster clasp runs 8-14 mm long for a bracelet/necklace class, a spring-ring clasp 6-10 mm diameter, and a toggle clasp's bar must be >=1.5x its own ring's inner diameter so it cannot slip back through under tension.","applies":["clasp","bracelet","necklace"],"value":{"min":6,"max":14,"unit":"mm"},"basis":"Clasp footprint scales with the chain class it closes and, for a toggle, with the geometric margin needed to keep the bar from re-threading itself under wear","sources":["iso-8653"],"tags":["clasp","lobster","toggle","spring-ring"]},{"id":"signet-ring-face-dimensions","kind":"dimension","tier":2,"title":"Signet ring face envelope","summary":"A signet ring's engraved face runs 10-16 mm along its long axis (oval or cushion) and 8-13 mm across, raised 1-2 mm proud of the shoulder, with engraving cut 0.2-0.4 mm deep to survive years of re-polishing.","applies":["signet ring"],"value":{"min":10,"max":16,"unit":"mm"},"basis":"Common adult signet face size that reads legibly at arm's length while still fitting the shoulder width of a normal band","sources":["iso-8653"],"tags":["signet","engraving","face"]},{"id":"watch-lug-to-lug","kind":"dimension","tier":2,"title":"Watch case lug-to-lug length","summary":"Lug-to-lug (the case's total length across both lug tips) runs roughly 1.15-1.25x the case diameter, e.g. a 40 mm case commonly spans 46-50 mm lug-to-lug, which is what actually determines wrist fit, not the stated diameter.","applies":["watch case"],"value":{"min":1.15,"max":1.25,"unit":"ratio"},"basis":"Lug-to-lug is the dimension that overhangs a small wrist even when the dial diameter looks reasonable, so it is sized off the case diameter rather than specified independently","sources":["watch-lug-guide"],"tags":["watch","lug-to-lug","fit"]},{"id":"watch-crystal-thickness","kind":"dimension","tier":2,"title":"Watch crystal thickness and seat","summary":"A mineral or sapphire crystal runs 1.0-2.0 mm thick, seated in a bezel rebate 0.3-0.5 mm deep with a compressed O-ring or gasket for water resistance, sapphire favouring the thinner end for its higher stiffness.","applies":["watch case"],"value":{"min":1,"max":2,"unit":"mm"},"basis":"Crystal thickness trades scratch/shatter resistance against case height and weight; sapphire's higher modulus lets it run thinner than mineral glass for the same impact resistance","sources":["watch-lug-guide"],"tags":["watch","crystal","sapphire"]},{"id":"watch-crown-dimensions","kind":"dimension","tier":2,"title":"Watch crown diameter and stem","summary":"A winding/setting crown runs 5-7 mm diameter on a 1.2 mm stem, projecting 3-4 mm from the case side for a fingernail grip without snagging on a cuff.","applies":["watch case"],"value":{"min":5,"max":7,"unit":"mm"},"basis":"Crown size balances a graspable grip diameter against how far it may project from the case before it catches on clothing","sources":["watch-lug-guide"],"tags":["watch","crown","stem"]},{"id":"watch-strap-thickness","kind":"dimension","tier":2,"title":"Watch strap thickness at the lug end","summary":"A leather or rubber strap runs 2-4 mm thick where it enters the lug, tapering to 1.5-3 mm at the buckle end so the strap doesn't fight the spring bar's own diameter inside the lug gap.","applies":["watch strap"],"value":{"min":1.5,"max":4,"unit":"mm"},"basis":"The strap must be thin enough at the lug to leave clearance around the spring bar while thick enough through its body to resist stretch and tear","sources":["nihs-spring-bar"],"tags":["watch","strap","thickness"]},{"id":"watch-buckle-width","kind":"dimension","tier":2,"title":"Watch buckle width","summary":"Size a pin or deployant buckle to the strap's taper-end width, typically 60-75% of the lug width, e.g. 14-16 mm buckle on a 20 mm lug strap.","applies":["watch strap"],"value":{"min":60,"max":75,"unit":"%"},"basis":"The strap tapers from the lug width down to the buckle so the closed strap doesn't look wider at the wrist than at the case","sources":["watch-lug-guide"],"tags":["watch","buckle","strap"]},{"id":"glasses-nose-pad","kind":"feature","tier":2,"title":"Adjustable nose pad geometry","summary":"A pad-arm nose pad runs 10-14 mm long to an 8-10 mm silicone or acetate pad, angled 15-25 degrees to match the nose bridge and spaced 14-20 mm apart at the pads to clear most bridge widths.","applies":["glasses","eyeglass frame"],"value":{"min":14,"max":20,"unit":"mm"},"basis":"Nose pad spacing and angle must match the range of human nasal bridge widths and slopes the frame is meant to fit without a custom adjustment","sources":["iso-12870"],"tags":["glasses","nose-pad","fit"]},{"id":"glasses-temple-tip","kind":"feature","tier":2,"title":"Temple tip (ear piece) curvature","summary":"The last 30-40 mm of a temple curves behind the ear at a 20-30 degree bend, sized so the tip doesn't press a point-load behind the ear under the frame's own clamping force.","applies":["glasses","eyeglass frame"],"value":{"min":30,"max":40,"unit":"mm"},"basis":"A gentle, generous-radius bend distributes the frame's clamping load over the ear-tip contact area instead of concentrating it at one point","sources":["iso-12870"],"tags":["glasses","temple","ear-tip"]},{"id":"smart-ring-basics","kind":"dimension","tier":2,"title":"Smart ring band width, thickness and battery basics","summary":"A smart ring's electronics band runs 6-8 mm wide and 2.2-2.9 mm thick (vs 1.5-3 mm for a plain metal band), housing a coin-cell-class battery around 15-25 mAh good for several days between charges.","applies":["ring","smart ring"],"value":{"min":6,"max":8,"unit":"mm"},"basis":"The electronics/battery stack inside a smart ring's shell needs more radial and axial section than a plain band, which is why a smart ring reads visibly thicker than a wedding band of the same diameter","sources":["oura-ring-5","galaxy-ring-wiki"],"tags":["smart-ring","wearable","battery"]},{"id":"cufflink-post-dimensions","kind":"dimension","tier":2,"title":"Cufflink post and toggle dimensions","summary":"A cufflink's fixed post runs 12-16 mm long on a 2-3 mm shank, with a swivel toggle bar 12-18 mm long that rotates 90 degrees to pass through a cuff buttonhole and lock crosswise.","applies":["cufflink"],"value":{"min":12,"max":18,"unit":"mm"},"basis":"The toggle must be long enough to lock securely crosswise behind the cuff fabric once rotated, while short enough to pass through a standard buttonhole when aligned with the post","sources":["iso-8653"],"tags":["cufflink","toggle","post"]},{"id":"brooch-pin-clasp","kind":"feature","tier":2,"title":"Brooch pin and C-clasp geometry","summary":"A brooch pin stem runs 30-50 mm long on a 0.8-1.0 mm wire, hinged at one end and locking into a C-clasp (rollover or safety-catch) sized to trap the pin tip with 1-2 mm of overlap so it can't work loose in fabric.","applies":["brooch"],"value":{"min":30,"max":50,"unit":"mm"},"basis":"Pin length must span enough fabric to hang securely under the brooch's own weight, and the catch overlap must exceed normal garment-flex movement so it doesn't self-release","sources":["iso-8653"],"tags":["brooch","pin","clasp"]},{"id":"charm-jump-ring-attach","kind":"feature","tier":2,"title":"Charm attachment loop","summary":"A charm's integral attachment loop runs 3-5 mm ID on 0.8-1.0 mm wire, sized to take a jump ring or bail without the charm's own loop being the weak link in the chain.","applies":["charm","bracelet","necklace"],"value":{"min":3,"max":5,"unit":"mm"},"basis":"The charm's loop must be at least as stiff as the jump ring it hangs from, or repeated swinging fatigues and opens the loop rather than the ring","sources":["iso-8653"],"tags":["charm","loop","attachment"]},{"id":"hypoallergenic-material-rule","kind":"rule","tier":2,"title":"Choosing a hypoallergenic alloy","summary":"For skin-contact or pierced-skin jewellery, specify implant-grade titanium (ASTM F136), 316L stainless (ASTM F138), niobium, or nickel-free 14k+ gold/platinum rather than nickel-bearing white gold or costume alloys, to pass EN 1811 without relying on plating.","applies":["ring","earring","bracelet","watch case"],"basis":"Plating wears through with handling and re-exposes a nickel-bearing base metal; specifying a nickel-free alloy from the start passes EN 1811 for the life of the part, not just when new","sources":["astm-f136","astm-f138","en-1811"],"tags":["hypoallergenic","nickel","titanium","316l"]},{"id":"process-lost-wax-casting","kind":"process","tier":2,"title":"Lost-wax casting workflow from a resin print","summary":"Print or carve a wax/castable-resin pattern, tree it onto a sprue base, invest in plaster, burn out the pattern at 700-900C, then centrifugal or vacuum-cast molten metal into the cavity within the same hour the flask leaves the kiln.","applies":["ring","pendant","casting"],"value":{"min":700,"max":900,"unit":"C"},"basis":"Burnout temperature must fully ash the wax/resin pattern without cracking the investment mould, and the flask must still be hot when cast or the metal freezes before filling thin sections","sources":["ganoksin-casting","materialise-gold-guide"],"tags":["casting","lost-wax","process","burnout"]},{"id":"process-dmls-jewelry","kind":"process","tier":2,"title":"DMLS direct metal printing for jewellery","summary":"DMLS prints gold/platinum/silver jewellery directly in metal powder, layer by layer, holding a 0.3-0.5 mm minimum wall for small decorative features but needing >=0.8 mm for a load-bearing band or prong, with support removal driving the practical floor.","applies":["ring","pendant","dmls"],"value":{"min":0.3,"max":0.8,"unit":"mm"},"basis":"DMLS can sinter a very thin section, but a wall below ~0.8 mm on a structural feature like a band or prong is fragile to depowder and finish without deforming","sources":["dmls-jewelry-guide"],"tags":["dmls","3d-printing","process"]},{"id":"process-polishing-finish","kind":"process","tier":2,"title":"Polishing allowance on a cast or printed part","summary":"Budget 0.05-0.15 mm of material removal per polished surface across tumbling, hand polishing and final buffing; a fine engraved or textured detail shallower than about 0.2 mm can polish away entirely if over-worked.","applies":["ring","pendant","bracelet","polishing"],"value":{"min":0.05,"max":0.15,"unit":"mm"},"basis":"Each polishing stage abrades a thin surface layer; cumulative removal across stages is what limits how shallow a cast or engraved detail can safely be","sources":["ganoksin-casting"],"tags":["polishing","finish","process"]},{"id":"test-prong-pull-retention","kind":"test","tier":2,"title":"Prong/bezel pull (stone-retention) test","summary":"Pull-test a set stone to roughly 5-10 N applied at the girdle without dislodging it; failing means thickening the prong tips (this pack's 0.8-1.2 mm) or adding prong count rather than relying on glue.","applies":["ring","pendant","prong setting","bezel setting"],"value":{"min":5,"max":10,"unit":"N"},"basis":"A worn or thin prong tip is the classic stone-loss failure mode; a pull test at a modest hand-jostling load exposes it before the piece ships","sources":["gia-diamond-sizes"],"tags":["test","retention","prong","pull"]},{"id":"test-wear-abrasion-plating","kind":"test","tier":2,"title":"Wear/abrasion test for plating and polish","summary":"Tumble or Taber-abrade a plated or brushed surface for 500-1000 cycles; a plated part must keep >=0.3 um of coating over the highest-wear contact points (band shoulders, bezel rim) or the base alloy (and its nickel content) is exposed.","applies":["ring","bracelet","watch case"],"value":{"min":500,"max":1000,"unit":"cycles"},"basis":"Plating wears fastest at raised, frequently-contacted geometry; the cycle test targets exactly those high points rather than a flat coupon","sources":["en-1811"],"tags":["test","wear","abrasion","plating"]},{"id":"test-ring-deformation","kind":"test","tier":2,"title":"Ring out-of-round deformation test","summary":"Load a ring band radially to 50-100 N (a snug removal-over-a-knuckle force) and require it to spring back within 0.1 mm of round; failing means the band's radial thickness (this pack's cast/printed minimums) needs increasing, not just a harder alloy.","applies":["ring","wedding band"],"value":{"min":50,"max":100,"unit":"N"},"basis":"A ring is routinely squeezed elliptical passing a knuckle; a band that stays permanently out-of-round after that load will bind or spin on the finger","sources":["iso-8653"],"tags":["test","deformation","ring","spring-back"]},{"id":"test-watch-glasses-drop","kind":"test","tier":2,"title":"Drop test for a watch case or glasses frame","summary":"Drop a watch case or glasses frame 1000 mm onto a hard surface on its most vulnerable corner (lug tip, hinge barrel); surviving needs a lug/hinge wall thick enough not to crack, per this pack's lug and hinge-screw dimensions.","applies":["watch case","glasses","eyeglass frame"],"value":{"value":1000,"unit":"mm"},"basis":"A worn wearable is routinely dropped from hand/face height onto a hard floor; the lug and hinge are the thin, stress-concentrated features that fail first","sources":["iso-12870"],"tags":["test","drop","watch","glasses"]},{"id":"material-gold-alloys","kind":"material","tier":2,"title":"Gold alloy densities (fine gold and 14k)","summary":"Fine (24k) gold is 19.3 g/cm3; alloying down to 14k (58.3% gold) with silver/copper/palladium drops density to roughly 13 g/cm3, which is what should drive a cast-part weight estimate, not the 24k figure.","applies":["ring","pendant","bracelet","casting"],"value":{"table":[{"alloy":"24k-fine-gold","densityGcm3":19.3},{"alloy":"14k-gold","densityGcm3":13}],"unit":"g/cm3"},"basis":"Karat alloying dilutes gold with lighter base metals proportionally to the non-gold fraction, so density scales roughly with karat purity","sources":["density-reference"],"tags":["material","gold","density","karat"]},{"id":"material-silver-925","kind":"material","tier":2,"title":"Sterling silver (925) density","summary":"Sterling silver (92.5% Ag, 7.5% Cu, the standard jewellery alloy) is 10.4 g/cm3; use this figure, not pure silver's 10.5, for weight-from-volume estimates on a cast or printed silver part.","applies":["ring","pendant","bracelet","casting"],"value":{"value":10.4,"unit":"g/cm3"},"basis":"925 sterling is the near-universal jewellery-grade silver alloy; its copper content marginally lowers density from pure silver while raising hardness enough to hold a set stone","sources":["density-reference"],"tags":["material","silver","sterling","density"]},{"id":"material-titanium-grade5","kind":"material","tier":2,"title":"Titanium (Grade 5 / Ti-6Al-4V) for hypoallergenic pieces","summary":"Titanium runs 4.5 g/cm3, under a quarter the density of gold, making it the lightest common hypoallergenic option for a large ring, bangle or watch case; it does not readily solder or size like gold/silver, so it is usually machined or DMLS-printed, not cast-and-resized.","applies":["ring","watch case","bangle"],"value":{"value":4.5,"unit":"g/cm3"},"basis":"ASTM F136 implant-grade Ti-6Al-4V ELI datasheet density; titanium's biocompatibility and low density make it common in large-format or hypoallergenic pieces","sources":["astm-f136"],"tags":["material","titanium","density","hypoallergenic"]},{"id":"material-316l-stainless","kind":"material","tier":2,"title":"316L stainless steel for watch cases and posts","summary":"316L surgical stainless is 8.0 g/cm3, the standard low-nickel-release alloy for watch cases, bracelets and earring posts where cost rules out titanium but EN 1811 compliance is still required.","applies":["watch case","bracelet","earring"],"value":{"value":8,"unit":"g/cm3"},"basis":"ASTM F138 316L datasheet density; its low, tightly-bound nickel content (vs free-machining stainless grades) is what lets it pass EN 1811 where a generic 304 stainless would not","sources":["astm-f138"],"tags":["material","316l","stainless","density"]},{"id":"recipe-plain-band-ring","kind":"recipe","tier":2,"title":"Recipe: plain wedding band, US size 7, comfort-fit wall","summary":"Build a US size 7 (17.3 mm ID) plain band 6 mm wide and 1.8 mm radial wall by revolving a rectangular r-z profile a full turn about the ring axis.","applies":["ring","wedding band"],"basis":"Combines ring-size-us-uk-table (17.3 mm ID), band-width-range (6 mm) and band-thickness-by-process (cast-gold 1.2 mm floor, used here at 1.8 mm) into one buildable revolve","sources":["iso-8653","materialise-gold-guide"],"tags":["recipe","ring","band"],"recipe":{"prompt":"Model a US size 7 plain wedding band: 17.3mm inner diameter, 6mm wide, 1.8mm radial wall thickness","steps":[{"tool":"cad_revolve_profile","args":{"profile":[[8.65,-3],[10.45,-3],[10.45,3],[8.65,3]]},"note":"revolve a rectangular r-z profile a full turn: inner radius 8.65mm (17.3mm ID), outer radius 10.45mm (1.8mm wall), 6mm band width along z"}],"expect":{"volume":648.05,"faceCount":4,"watertight":true,"note":"measured 2026-09-19: agrees with the kernel on the CADSF-1630 corpus sweep — volume inside the 0.5% band and faceCount exact"}}},{"id":"recipe-pendant-tag-bail","kind":"recipe","tier":2,"title":"Recipe: round pendant tag with an integral bail","summary":"Build a 20 mm diameter, 2 mm thick pendant tag with an integral bail loop (torus, 4.5 mm outer diameter, 1.5 mm tube) on its top edge sized for a 1.5 mm-gauge chain.","applies":["pendant","bail","charm"],"basis":"Combines a plain disc tag with pendant-bail-clearance-rule (bail ID >= chain diameter + 1mm, here 1.5mm chain needs >=2.5mm ID, given as a 3mm-ID/1.5mm-tube torus) unioned onto the tag","sources":["iso-8653"],"tags":["recipe","pendant","bail"],"recipe":{"prompt":"Model a 20mm diameter, 2mm thick round pendant tag with a small bail loop on the top edge for a 1.5mm chain","steps":[{"tool":"cad_cylinder","args":{"r":10,"h":2},"note":"20mm diameter x 2mm thick tag disc"},{"tool":"cad_torus","args":{"R":2.25,"rmin":0.75,"origin":[0,8.5,1],"rotate":{"rx":1.5707963}},"note":"bail loop, 3mm ID x 1.5mm tube, tipped upright and overlapping the tag's top edge so it fuses on union"},{"tool":"cad_boolean_union","args":{"of":"$0","tool":"$1"},"note":"fuse the bail onto the tag (CADSF-1604: expect re-pinned to the analytic 8-face union — the old 3538 was a tessellated-era face count of the same body)"}],"expect":{"volume":645.24,"faceCount":8,"watertight":true,"note":"measured 2026-09-19: agrees with the kernel on the CADSF-1630 corpus sweep — volume inside the 0.5% band and faceCount exact"}}},{"id":"recipe-watch-bezel-ring","kind":"recipe","tier":2,"title":"Recipe: watch-case bezel ring, 40mm case, 34mm crystal opening","summary":"Build a 40 mm outer diameter, 8 mm tall watch-case bezel ring with a 34 mm crystal opening by revolving a rectangular r-z profile a full turn about the case axis.","applies":["watch case"],"basis":"Combines watch-case-diameter-range (40mm typical) with a crystal-opening bore into one buildable revolve, the case-diameter twin of the plain-band-ring recipe","sources":["watch-lug-guide"],"tags":["recipe","watch","bezel"],"recipe":{"prompt":"Model a 40mm diameter, 8mm tall watch-case bezel ring with a 34mm crystal opening","steps":[{"tool":"cad_revolve_profile","args":{"profile":[[17,-4],[20,-4],[20,4],[17,4]]},"note":"revolve a rectangular r-z profile a full turn: inner radius 17mm (34mm crystal opening), outer radius 20mm (40mm case diameter), 8mm case height along z"}],"expect":{"volume":2789.73,"faceCount":4,"watertight":true,"note":"measured 2026-09-19: agrees with the kernel on the CADSF-1630 corpus sweep — volume inside the 0.5% band and faceCount exact"}}}]}