Product and application brief
A precision shim compensates a defined gap or tolerance stack between mating components. Its controlled thickness and profile are part of the fit requirement, rather than an unspecified washer thickness. State the final installed gap, drawing revision and measurement conditions before selecting a ring or other shim shape.
Product forms and reference names
| Choice or field | What to identify |
|---|---|
| Solid shim or ring | A single-piece flat adjustment element with a specified thickness and profile. Ring geometry does not alone establish a DIN 988 product or precision tolerance. |
| Laminated adjustment shim | Bonded thin layers permit thickness adjustment by removing selected layers according to the chosen product instructions. Identify full or partly solid construction. |
| Edge-bonded shim pack | Individual sheets are held together at their edges rather than bonded over their full faces. Specify layer count, thickness and which remaining combination is required. |
| Supporting ring | DIN 988 names supporting rings separately from axial shim rings. Select the support requirement at a retaining-ring interface, not merely the thickness needed to remove play. |
DIN 988 edition and product identity
DIN Media lists DIN 988:2025-12 as current for shim rings and supporting rings, replacing the 1990-03 edition. Its overview distinguishes axial positioning/play compensation from supporting rings used at retaining-ring interfaces where chamfers or bevels matter. Specify the selected type and edition; an older catalogue callout or similar shape does not establish current supplied-part conformity. Full normative dimensions, tolerances and technical requirements are not reproduced here.
Solid, laminated and edge-bonded are not synonyms
SPIROL's original shim information includes single-sheet, laminated and edge-bonded forms. Its laminated-shim discussion describes removable bonded layers and partly solid variants. Its original FAQ separates edge joining from face bonding. Identify the required construction explicitly; do not assume that any shim pack can be peeled, that removed layers are reusable, or that its adjustment increment is universal.
Define the finished thickness and inspection basis
Give the target installed thickness or gap and allowed variation, not only a nominal stock thickness. For a pack, specify layer thicknesses, total supplied thickness and the permitted remaining configuration. Agree where and under what conditions thickness is measured, and which flatness, parallelism, edge and surface requirements apply. These must come from the controlled specification; this page promises no numerical precision.
Interfaces, handling and application limits
Identify contact faces, holes or slots, radial envelope, motion at the interface and environmental exposure. A shim used only for static spacing is not automatically a qualified thrust bearing, hardened support or elastic spring. Follow the selected material and bonded-layer instructions for handling and adjustment. Exact material, adhesive suitability, wear or temperature limits need application-specific evidence.
Specification fields
| Choice or field | What to identify |
|---|---|
| Identity and profile | Solid, laminated, partly solid or edge-bonded; ring or drawing profile, inside/outside diameters, holes/slots and exact drawing/revision or product code. |
| Thickness and fit | Target installed thickness or gap, nominal supplied thickness, permitted variation, units and mating assembly datum. |
| Layer construction | If applicable: layer thicknesses/count, solid portion, bonded area and permitted adjustment sequence or remaining pack; request instructions. |
| Geometric and surface control | Required flatness, parallelism, thickness measurement locations/conditions, edge/burr control and contact-surface requirements from the selected specification. |
| Material and service | Requested alloy/condition/finish, bonded construction if relevant, static or moving contact and actual temperature/exposure; no generic suitability guarantee. |
| Retaining interface | For axial ring applications: mating shaft/bore, groove/retaining-element identity, abutment and chamfer geometry; distinguish shim from supporting-ring function. |
| Order and evidence | Quantity as individual shims or defined packs, thickness identification, segregation/packing, inspection and requested documents; actual scope and delivery require confirmation. |
Common product questions
Is a precision shim just a thin flat washer?
Not necessarily. A shim is selected to achieve a controlled fit or thickness requirement. An ordinary flat washer cannot be assumed to meet that requirement without its drawing and inspection evidence.
Which DIN 988 edition should the enquiry name?
State the required edition explicitly. DIN Media lists 2025-12 as current and replacing 1990-03. Confirm the selected type, requirements and evidence rather than assuming catalogue interchangeability.
Can every layered shim be peeled the same way?
No. Face-bonded laminates, partly solid constructions and edge-bonded packs differ. Obtain the chosen layer data and adjustment instructions; do not assume universal layer thickness or reuse.
Related product choices
- Flat washers: ordinary bearing elements
- Retaining rings: identify the axial retention interface
- Drawing-based shim profiles and spacer requirements
Product references
References checked 9 October 2026 identify structures, not FastenerBridge stock, certification or brand affiliation. Final requirements follow the selected specification. No universal dimensions, load rating or tightening torque is stated.