JIS B 2401 P-series

P-21 O-Ring Size

Nominal free-state dimensions from the verified public-reference subset used by this site.

Inside diameter20.8 mm±0.23 mm

Cross-section2.4 mm±0.09 mm

Outside diameter25.6 mm

Dimensions

JIS name: P-21

ID × CS: 20.8 × 2.4 mm

OD = ID + 2 × CS = 25.6 mm

Closest AS568 dimension

AS568-117

20.29 × 2.62 × 25.53 mm

This is a dimensional comparison only, not an interchangeability claim.

About tolerances

The public reference table notes that the listed dimensional tolerances are based on NBR. Different elastomer compounds may have different tolerances.

Nearby JIS P sizes

AS568 ↔ JIS comparison

Standard	ID (mm)	CS (mm)	OD (mm)
P-21	20.8	2.4	25.6
AS568-117	20.29	2.62	25.53

The AS568 result is the closest dimensional match in the current AS568 dataset. Similar dimensions do not establish interchangeability.

Cross-reference

Compare this JIS size with AS568 using the site's dimensional cross-reference tool.

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O-ring selector

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Groove check

Check preliminary squeeze, fill estimate and installation stretch.

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Source

Public JIS B 2401 P-series reference table

The official JIS standard may require licensed access. This page reproduces only the verified public-reference dimensional fields used for this site.