Description
ISO 7089 WASHER 4×9 STEEL GRADE A PLAIN NORMAL SERIES — BOLTON SKU 69191.
About the Plain Washer ISO 7089 4×9 mm
This item is a plain flat washer manufactured to ISO 7089, the international standard for normal-series plain washers without chamfer in product grade A. The 4×9 size designation corresponds to the M4 nominal fastener size: under ISO 7089 the M4 washer has a 4.3 mm clearance hole, a 9 mm outside diameter and a 0.8 mm nominal thickness. The washer is steel in a plain (uncoated) finish, as stated in the designation; ISO 7089 steel washers are commonly produced in the 200 HV hardness class. Plain washers of this pattern distribute the clamping load of a bolted joint over a larger bearing area, protect the mating surface from damage during tightening and bridge clearance holes. Because the dimensions are fixed by the ISO standard, the part is fully interchangeable with any compliant manufacturer’s product of the same size and grade.
Key specifications
| Standard | ISO 7089 — plain washers, normal series, grade A |
|---|---|
| Nominal size | M4 (designation 4×9) |
| Clearance hole | 4.3 mm |
| Outside diameter | 9 mm |
| Thickness | 0.8 mm nominal |
| Material / finish | Steel, plain |
Typical applications
ISO 7089 washers are consumed across equipment assembly, panel and bracket fixing, and MRO fastening work in aerospace, defence and industrial workshops, wherever standard metric bolted joints are built or refurbished.
Supplied by BOLTON Technical Equipment Supplies against request for quotation. Add this item to your RFQ basket to request pricing, lead time and documentation requirements (e.g. CoC, datasheets or test reports where applicable).
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