O-Ring Size Chart — AS568 Dash Numbers with ID, OD & Cross-Section

O-rings are sized by AS568 dash numbers — a standard where each number defines an exact inside diameter and cross-section. Find your dash number below (or measure your ring and work backwards with the O-ring size calculator). Sizes we stock link straight to the product.

1/16" Cross-Section Series (-0XX)

Dash #	ID	OD
-008	3/16"	5/16"
-010	1/4"	3/8"	In stock (100-pack)
-011	5/16"	7/16"	In stock (100-pack)
-012	3/8"	1/2"
-014	1/2"	5/8"
-017	11/16"	13/16"	In stock (100-pack)
-020	7/8"	1"

3/32" Cross-Section Series (-1XX)

-110	3/8"	9/16"
-112	1/2"	11/16"
-114	5/8"	13/16"
-116	3/4"	15/16"
-121	1-1/16"	1-1/4"	In stock (100-pack)
-126	1-3/8"	1-9/16"

1/8" Cross-Section Series (-2XX)

-210	3/4"	1"
-214	1"	1-1/4"
-222	1-1/2"	1-3/4"
-230	2-1/2"	2-3/4"	In stock (10-pack)
-236	3-1/4"	3-1/2"

3/16" Cross-Section Series (-3XX)

-325	1-1/2"	1-7/8"
-342	3-1/2"	3-7/8"	Standard 10" water filter housing size
-357	5-1/2"	5-7/8"	In stock — also sold as the Big Blue housing O-ring

How to Read the System

The first digit family sets the cross-section (-0XX = 1/16", -1XX = 3/32", -2XX = 1/8", -3XX = 3/16"); the remaining digits step through inside diameters. OD always equals ID + 2x cross-section. Measuring a worn ring? Use calipers on ID and thickness (never a stretched ring), or measure the groove — the walkthrough is on the O-ring size calculator. Compound selection (Buna-N vs EPDM vs silicone) is on the compatibility chart.

Need a dash size we don't stock, or a full assortment for the shop? Email customerservice@rubberfeetwarehouse.com — bulk and special-order pricing available.