What size is an AS568-214 o-ring?

AS568-214 has a 0.9840 in (24.990 mm) inside diameter and a 0.1390 in (3.530 mm) cross-section, giving a 1.2620 in (32.050 mm) outside diameter.

How do AS568 dash numbers work?

The dash number encodes the cross-section series and the size within it: 001-003 is a 0.040-0.060 in cross-section, 004-050 is a 0.070 in cross-section, 102-178 is a 0.103 in cross-section, 201-284 is a 0.139 in cross-section, 309-395 is a 0.210 in cross-section, 425-475 is a 0.275 in cross-section. Within a series the cross-section is constant and only the inside diameter changes, which is why one gland depth serves a whole series.

Are AS568 sizes the same as metric o-ring sizes?

No. AS568 is an inch standard, so its metric figures are exact conversions of inch dimensions rather than round metric sizes. An ISO 3601 metric ring that looks close — 25 × 3.5 mm against a 24.99 × 3.53 mm AS568-214 — is a different part with different tolerances.

What gland depth does an AS568 o-ring need?

Gland depth is set by the cross-section, not the inside diameter, so it is the same for every size in a series. This reference carries verified static squeeze bands for 5 of the 6 cross-section series, from MIL-G-5514G; each size page shows the band for its own series.

Reference · AS568 o-rings

AS568 O-Ring Size Chart — All 349 Dash Numbers

https://shopmath.org/o-rings · data verified August 1, 2026

An AS568-214 o-ring is 0.9840 in (24.990 mm) inside diameter × 0.1390 in (3.530 mm) cross-section. All 349 AS568 dash numbers across 6 cross-section series, each with inside diameter, cross-section, outside diameter, free-state tolerances and — where a verified band exists — static gland depth. Dimensions are free-state, before installation.

Sizes: 349
Series: 6
Gland rules: 6
Verified: August 1, 2026

Most looked-up size · AS568-214 · inside Ø × cross-section

0.9840 × 0.1390 in

Inside Ø: 24.990mm
Cross-section: 3.530mm
Outside Ø: 32.050mm

Free-state dimensions with AS568 tolerances. Full AS568-214 page →

AS568 O-Ring Cross-Section Series

Every dash number belongs to a cross-section band, and the band decides the gland. Pick a series to jump to its full index below.

AS568 o-ring cross-section series and their coverage
Series	Cross-section	Sizes	Smallest ID, mm	Largest ID, mm	Static gland data	What it is
001-003	0.040-0.060 in	3	0.740	1.420	—	Three one-off micro sizes, each with its own cross-section.
004-050	0.070 in	47	1.780	133.070	yes	The 1/16 in cross-section band, dash 004 through 050.
102-178	0.103 in	77	1.240	247.320	yes	The 3/32 in cross-section band, dash 102 through 178.
201-284	0.139 in	84	4.340	456.060	yes	The 1/8 in cross-section band, dash 201 through 284.
309-395	0.210 in	87	10.460	658.880	yes	The 3/16 in cross-section band, dash 309 through 395.
425-475	0.275 in	51	113.670	658.880	yes	The 1/4 in cross-section band, dash 425 through 475.

A series appears here only when it carries at least three verified sizes. Static gland data exists where MIL-G-5514G publishes a verified squeeze band for that cross-section.

Most Looked-Up AS568 O-Ring Sizes

Commonly specified AS568 o-ring sizes
Property	Inside Ø		Property	Property
Size	in	mm	Cross-section, in	Outside Ø, in
AS568-010	0.2390	6.070	0.0700	0.3790
AS568-014	0.4890	12.420	0.0700	0.6290
AS568-110	0.3620	9.190	0.1030	0.5680
AS568-112	0.4870	12.370	0.1030	0.6930
AS568-116	0.7370	18.720	0.1030	0.9430
AS568-210	0.7340	18.640	0.1390	1.0120
AS568-214	0.9840	24.990	0.1390	1.2620
AS568-218	1.2340	31.340	0.1390	1.5120
AS568-222	1.4840	37.690	0.1390	1.7620
AS568-325	1.4750	37.470	0.2100	1.8950
AS568-330	2.1000	53.340	0.2100	2.5200
AS568-425	4.4750	113.670	0.2750	5.0250

Every AS568 O-Ring Dash Number in the 001-003 Series

3 sizes, all on a 0.040-0.060 in cross-section, from 0.740 mm to 1.420 mm inside diameter.

Every AS568 O-Ring Dash Number in the 004-050 Series

47 sizes, all on a 0.070 in cross-section, from 1.780 mm to 133.070 mm inside diameter.

Every AS568 O-Ring Dash Number in the 102-178 Series

77 sizes, all on a 0.103 in cross-section, from 1.240 mm to 247.320 mm inside diameter.

Every AS568 O-Ring Dash Number in the 201-284 Series

84 sizes, all on a 0.139 in cross-section, from 4.340 mm to 456.060 mm inside diameter.

Every AS568 O-Ring Dash Number in the 309-395 Series

87 sizes, all on a 0.210 in cross-section, from 10.460 mm to 658.880 mm inside diameter.

Every AS568 O-Ring Dash Number in the 425-475 Series

51 sizes, all on a 0.275 in cross-section, from 113.670 mm to 658.880 mm inside diameter.

Common Questions About AS568 O-Ring Sizes

What size is an AS568-214 o-ring?: AS568-214 has a 0.9840 in (24.990 mm) inside diameter and a 0.1390 in (3.530 mm) cross-section, giving a 1.2620 in (32.050 mm) outside diameter.
How do AS568 dash numbers work?: The dash number encodes the cross-section series and the size within it: 001-003 is a 0.040-0.060 in cross-section, 004-050 is a 0.070 in cross-section, 102-178 is a 0.103 in cross-section, 201-284 is a 0.139 in cross-section, 309-395 is a 0.210 in cross-section, 425-475 is a 0.275 in cross-section. Within a series the cross-section is constant and only the inside diameter changes, which is why one gland depth serves a whole series.
Are AS568 sizes the same as metric o-ring sizes?: No. AS568 is an inch standard, so its metric figures are exact conversions of inch dimensions rather than round metric sizes. An ISO 3601 metric ring that looks close — 25 × 3.5 mm against a 24.99 × 3.53 mm AS568-214 — is a different part with different tolerances.
What gland depth does an AS568 o-ring need?: Gland depth is set by the cross-section, not the inside diameter, so it is the same for every size in a series. This reference carries verified static squeeze bands for 5 of the 6 cross-section series, from MIL-G-5514G; each size page shows the band for its own series.

Sources and Method for the AS568 O-Ring Data

SAE AS568 o-ring sizes and gland designcomputed+compiled

bd_warehouse o-ring_parameters.csv (Apache-2.0) + KasperCalc oring-sizes.js (MIT), agreeing on all 349 sizes; OD computed; gland depth computed from squeeze %

Verified against o-rings: 21 checks passed across 3 harness(es)

Part computed from the standard's formulas, part compiled from agreeing public sources.

Formula

Outside diameter

OD  =  ID + 2 × CS

Static gland depth

depth  =  CS − (CS × squeeze%)

Squeeze bands are the MIL-G-5514G static criteria; the depth is that percentage applied to the nominal cross-section.

Assumptions

Dimensions are free-state, at room temperature, before installation.
Gland figures are static only — no verified squeeze band exists in this dataset for dynamic service, and none is invented.
Dataset scope: A fabricated-dataset negative control is asserted against on every run. EXCLUDED: groove width, corner radius, diametral clearance, back-up ring widths, surface finish, all dynamic glands, the 900-series, and ISO 3601 metric sizes.

Data last verified

August 1, 2026

How this data is built and checked →

How to Cite This AS568 O-Ring Reference

Citation

ShopMath. "AS568 O-Ring Size Chart — All 349 Dash Numbers." ShopMath, verified August 1, 2026, https://shopmath.org/o-rings

BibTeX

@misc{shopmath-o-rings,
  title        = {AS568 O-Ring Size Chart — All 349 Dash Numbers},
  author       = {{ShopMath}},
  year         = {2026},
  howpublished = {\url{https://shopmath.org/o-rings}},
  note         = {Data verified 2026-08-01}
}

Permanent URL

https://shopmath.org/o-rings