AS568 O-Ring Size Chart: How Dash Sizes Work
Quick Answer
An AS568 dash number is a useful inch-size lookup shortcut, but it is not the whole buying decision. Use the dash size to narrow the family, then confirm ID, CS, OD, material, and quantity path before ordering. Known size and small quantity can go to Shop Small Packs; uncertain measurements should start with the Size Guide; material questions should go through the Material Guide; drawings, samples, or larger quantity needs should use Bulk Quote.
Definition: What the Dash Number Means
The dash number points to a standard O-ring size family. It helps buyers talk about a nominal size, but the final selection still depends on the actual part, groove, material, and use case.
How to Use a Dash Size Without Overreaching
- Use the dash number as a lookup cue.
- Confirm ID and CS against the old part, groove, or approved drawing.
- Use OD as a quick check after ID and CS are known.
- Review material separately instead of assuming the dash number answers it.
- Choose Shop Small Packs for known small-quantity needs or Bulk Quote when review is needed.
Decision Path
If the dash number, material, and quantity are clear, the next action can be simple. If any of those are uncertain, slow down and confirm the missing part of the decision. The Size Guide, Material Guide, and Bulk Quote routes exist to prevent a size lookup from becoming an unsupported fit assumption.
FAQ
What should I do first if I already know the size?
Go to Shop Small Packs when the size, material, and quantity are clear.
What if I do not know the O-ring size?
Start with the Size Guide and measure ID and CS before ordering.
What if I am not sure about material?
Use the Material Guide to compare material families before choosing a product path.
When should I use Bulk Quote?
Use Bulk Quote for samples, drawings, unusual setups, larger quantities, or any review-needed requirement.
Evidence Layer
Evidence level: scene_inference_only. GSC and GA4 need separate OAuth repair before own-site metrics can be used. Semrush keyword evidence is not used when quota/runtime status is blocked. SerpAPI, when available, is used only for SERP intent, not search volume, ranking, traffic, or conversion claims.
Final Takeaway
Use the article as a decision path, not as a performance promise: identify the sizing system, confirm the dimensions, review material separately, and choose the correct buying route.
