Titanium Flat Washers (DIN 125 / ISO 7089)

Titanium flat washers are the simplest component in the fastener kit — a plain circular disc with a central hole, used to distribute the clamping force of a bolt or screw over a larger area on the mating surface. They serve two key purposes: load distribution (reducing bearing stress on softer or thinner materials) and surface protection (preventing the bolt / nut face from directly indenting or damaging the mating part). Titanium washers also match the corrosion resistance of titanium bolts and screws, eliminating bi-metallic corrosion.

Commonly referenced to DIN 125, which defines two standard outer diameter series: DIN 125-A (narrow) and DIN 125-B (wide). ISO 7089 is the international equivalent for narrow-series washers. Feinuotai supplies washers matched to bolt sizes from M3 through M48 in Grade 2 CP titanium and Grade 5 Ti-6Al-4V alloy.

Product Range & Specifications

DIN 125 commonly referenced — specify A or B series at inquiry.

Size Matching

Inner diameter matched to bolt / screw nominal diameter. Outer diameter per DIN 125-A (narrow) or DIN 125-B (wide).

Diameter & Series

Standard Range: M3–M48 matching. DIN 125-A (narrow OD) & DIN 125-B (wide OD) both available.
Custom Supply: Non-standard inner / outer diameters and thicknesses per drawing.
Stock Availability: M5–M24 DIN 125-A in Gr2 & Gr5.

Thickness

Standard thickness per DIN 125 (function of inner diameter). Custom thickness available on request.

Grade Options

Regular: Grade 2 (CP Ti) & Grade 5 (Ti-6Al-4V alloy).
Coordinated: Grade 1, Grade 7, Grade 9, Grade 23 — subject to order quantity.
Note: Washer grade should be matched to bolt / nut grade for consistent joint strength.

Standard References

DIN 125 (metric flat washer, A & B series), ISO 7089 (narrow series).

Packaging

Bag / box / wooden case per request. Bulk and export packaging supported.

Typical Application Areas

Chemical Equipment

Corrosion-resistant load distribution for bolted assemblies.

Marine / Offshore

Saltwater-resistant washer pairs eliminating bi-metallic corrosion.

General Industrial

Protecting thin sheet metal, soft metals and FRP from bolt face damage.

Aerospace Secondary

Load distribution in low-load and non-critical assemblies.

Quality & Documentation

Material test certificates, dimensional reports (inner diameter, outer diameter, thickness, flatness) and surface finish documentation available per order.

Frequently Asked Questions

When should I use DIN 125-A vs DIN 125-B washers?

DIN 125-A (narrow series): standard washer with a smaller outer diameter. Appropriate for most general industrial and heavy-duty use where clearance is tight.
DIN 125-B (wide series): larger outer diameter for better load distribution on softer or thinner materials (e.g. sheet metal, FRP, plastic). Also used for bolted joints where contact area maximization is critical. Specify the series at inquiry.

Do I always need a washer under a titanium bolt?

Not in every case, but strongly recommended when: the mating surface is softer than the titanium bolt head (e.g. aluminum, brass, plastic), the mating surface is thin or fragile, or the application is subjected to vibration or cyclic loading. Use your engineering judgment — we can advise on specific joint details.

Is a flat washer the same as a "hardened washer" or "spring washer"?

No. Titanium DIN 125 flat washers are plain discs for load distribution. Hardened washers provide increased bearing strength for high-strength steel bolts (not standard titanium practice). Spring / lock washers have serrated edges for anti-loosening. Specify the exact washer type you require.