Specify the dimensions that control axial spacing, radial location and assembly contact.
Geometry Before Naming
OD, ID, Thickness and Faces Define the Component
Rings and washers are annular parts controlled by outside diameter, inside diameter, wall and concentricity. Spacers and shims are controlled primarily by finished thickness, parallelism and the condition of their two contact faces.
Name the assembly function.A sealing land, optical spacer and electrical isolator may share the same outline but require different materials, surfaces and inspection.
Ring OD5-300 mmReference range
Minimum WallApprox. 1.5 mmGeometry dependent
Spacer Thickness0.05-10 mmShim to rigid spacer
Thickness Control+/-0.01 mmPrecision reference range
ConcentricityApprox. 0.05 mmReviewed by OD, ID and wall
FacesGround / lapped / polishedFunctional faces only if preferred
Ring & Stack Planner
Check Wall, Cross-Section and Stack Height
Use nominal dimensions to see whether the part behaves like a robust ring or a thin-wall precision component. The tool is an RFQ aid, not a strength calculation.
Nominal geometry only. Grooves, chamfers, lapping allowance and tolerances are excluded.
OD 80ID 50T = 3 mm
Radial Wall15.00 mm
Nominal Mass34.1 g
Stack Height12.00 mm
Wall is above the 1.5 mm reference review point.
01
Why Concentricity Is Not an OD Tolerance
OD and ID can each pass their size limits while the bore still sits off-center. Concentricity controls the relationship between the two circles and therefore the minimum wall around the ring. It matters when the ring locates a tube, lens, seal or rotating feature.
Product Forms
Choose the Form by Assembly Role
These are functional part families, not cosmetic variants.
01
Radial Location
Plain / Stepped Rings
Annular parts with controlled OD and ID; shoulders or steps add axial seating and mechanical location.
02
Seal or Flow Interface
Grooved Rings
Face, OD or ID grooves locate seals, retain adjacent components or create a controlled clearance path.
03
Fastener Isolation
Glass Washers
Compact annular spacers used around shafts, tubes and fasteners where a nonmetallic interface is required.
04
Axial Distance
Precision Spacers
Flat parts ground or lapped to establish stack height, optical separation or component position.
05
Fine Adjustment
Ultra-Thin Shims
Thin sections from approximately 0.05 mm for optical packaging, sensors and precision mechanical stacks.
06
Combined Location
Custom Spacer Blocks
Non-annular outlines with holes, pockets, slots or shoulders where spacing and alignment are integrated.
Assembly Stack Viewer
Control the Contact Faces, Not Only Nominal Thickness
A spacer can meet its average thickness and still tilt an optical element if the two faces are not sufficiently parallel. Lapping is selected when stack height and face relationship matter together.
For hidden mating surfaces and general mechanical spacing.
LappedParallel face pair
Improved thickness uniformity and flatness for controlled stacks.
PolishedClear contact surface
Used where transmission, bonding or cleanliness requires a smoother finish.
Optical PolishSpecified optical zone
Applied only when the face participates in an optical path.
02
Why Stack Tolerance Grows With Part Count
Four spacers with independent thickness variation create a wider possible total than one part. State the required assembled stack height and whether parts may be matched or sorted; do not tighten every spacer automatically without checking the actual assembly need.
Material Routes
Borosilicate for Practical Stability, Fused Silica for Lower Expansion
Material
Decision Reason
Typical Component
Soda-Lime
Economical general spacing and isolation
Washers and mechanical spacers
Borosilicate 3.3
Low expansion and good chemical durability
Laboratory, vacuum and equipment rings
Fused Silica / Quartz
Very low expansion, grade-specific optical and high-temperature behavior
Semiconductor, thermal and optical rings
Optical Glass
Controlled optical properties in an instrument stack
Lens spacing and instrument components
Thin Technical Glass
Stable precision thin sections
Sensor shims and electronic packaging
Material values and service temperatures are grade dependent. Confirm atmosphere, thermal gradient and purity requirements.
Feature Map
Add Location and Sealing Features Without Losing the Datum Logic
Every feature should be dimensioned from the functional OD, ID or face rather than chained around the drawing.
StepChamfer
01Internal / external stepsAxial seating and radial location
02Face or diameter groovesSeal, retention or clearance path
03Radial / axial holesFlow, alignment or fastener interface
04Chamfers and radiiHandling, assembly lead-in and edge protection
05Pockets and recessesLocal clearance or multi-level geometry
Manufacturing Route
Machine the Ring as a Related Set of Surfaces
OD, ID and feature geometry are coordinated before the functional faces receive their final thickness and finish.
01Blank & MaterialConfirm glass grade, allowance and orientation.
02OD / ID GenerationCut and grind annular geometry from common references.
03FeaturesAdd steps, grooves, holes, pockets and chamfers.
04Face FinishingGrind, lap or polish to thickness and parallelism.
05Cleaning & InspectionVerify geometry, surfaces and protective packing.
Inspection Map
Inspect the Feature That Controls Assembly
Reports can be organized around the ring axis, functional faces and added features.
Radial GeometryOD, ID, wall and concentricity
Axial GeometryThickness, parallelism and flatness
Feature GeometryGroove, step, hole and pocket position
Edge ConditionChamfer, chips, cracks and transition radii
Surface ConditionGrinding marks, polish and cosmetic zone
ReleaseMaterial identity, cleanliness and lot traceability
Procurement FAQ
Glass Ring & Spacer Questions
Answers centered on geometry, surfaces and assembly stack-up.
What dimensions are required for a glass ring?
State OD, ID, finished thickness, tolerances, concentricity, face condition, edge treatment and any steps, grooves or holes.
What is the difference between a ring, washer and spacer?
A ring describes annular geometry, a washer is usually a compact annular interface, and a spacer is defined by the distance it maintains. One part can fit more than one description.
What size range can be reviewed?
A reference envelope is about 5-300 mm OD with walls from approximately 1.5 mm, subject to material, thickness, feature geometry and finish.
Can very thin glass shims be produced?
Yes. Selected materials can be reviewed from approximately 0.05 mm, with handling, flatness and packing considered as part of the route.
Can both faces be lapped parallel?
Yes. Double-side lapping is appropriate when thickness variation, parallelism and stack height are more important than a simple ground finish.
Can rings include steps and grooves?
Yes. Internal or external steps, face grooves, radial or axial holes, chamfers, pockets and recesses can be reviewed from the drawing.
When should fused silica replace borosilicate?
Use it when lower expansion, higher thermal duty, purity or a specific optical transmission grade justifies the higher material and processing cost.
What should be sent for quotation?
Send material, OD, ID, thickness, tolerances, concentricity, face finish, features, quantity, application, cleanliness and inspection requirements.
Send OD, ID, thickness, material, face finish, critical relationships and quantity for a drawing-based review.
Saving your time and cost is our common pursuit.
Tell us the material, size, thickness, tolerance, quantity, application, and any holes, slots, edges, coating, printing, or polishing requirements. We can manufacture custom glass components from your drawing, CAD file, sketch, or sample.
