STAINLESS STEEL SHIM WASHERS DIN 988

Shim Washers DIN 988 — A shim washer does a fundamentally different job to almost every other washer in this range - it is not there to spread clamping load under a bolt head, it is there to take up space precisely. DIN 988 washers are thin, precision-ground, and supplied in fine thickness increments so they can be stacked in combination to set an exact axial clearance or fine-tune end-float in bearing and gear assemblies, where getting that clearance right by a small fraction makes the difference between a smoothly running assembly and one that binds or rattles. Where a standard flat washer is selected mainly on bore fit and bearing area, with thickness as a secondary consideration, a DIN 988 shim is selected almost entirely on its precise thickness - the bore just needs to clear the shaft or bolt it sits on. That makes it a mainstay of gearbox, bearing, and precision mechanical assembly, used for dimensional adjustment and compensating manufacturing tolerance between mating components, rather than for carrying significant clamping load; if a joint genuinely needs to transmit clamp force, a standard or spring washer is the correct choice, with shims reserved purely for the adjustment role. Material selection favours dimensional stability over strength: spring steel and stainless steel are the common choices, valued for holding their precise thickness consistently rather than for load capacity. Where corrosion resistance matters - assemblies exposed to moisture, washdown, or general outdoor use - A2 (304-equivalent) stainless is the sensible default, with A4 (316-equivalent) reserved for genuinely aggressive chemical or marine environments, since the cost difference is rarely justified purely by the shim's role rather than its exposure. Choosing the right shim washer means starting from the required end-float or clearance rather than the bolt size alone, building up the stack from standard thickness increments, and checking against DIN 988's published thickness series - Precision Shim Washers offer an even finer, purpose-built range where DIN 988 increments are not fine enough for the tolerance being chased.

FAQs
What are shim washers used for?
Setting axial end float in bearing and gearbox assemblies, fine adjustment of stack height in precision mechanical assemblies, and compensating for manufacturing tolerance between mating components - applications needing precisely controlled spacing rather than clamping load.

Are DIN 988 washers used under bolt heads for clamping?
They can be used in a bolted stack, but their primary function is dimensional adjustment rather than load-bearing; where high clamping load or vibration resistance is the requirement, a standard or spring washer is more appropriate.

How thin can a DIN 988 shim washer be?
DIN 988 covers a range of fine thicknesses specifically for building up precise stacks; the exact minimum for a given bore should be checked against the standard's thickness series rather than assumed.