1xx77 dash sizesID 0.049–9.737 inAS568

AS568 100 Series O-Rings — 0.103 in Cord

The 100 series carries a 0.103 in cord — 2.62 mm — and it is the family that fits the boss of a standard SAE straight-thread port. On tube and hose fittings this is the size range most often called out by dash number rather than measured.

AS568-140 — 100 seriesAS568 dimensions · inches · plan view normalised, cord section enlarged · not to a common scale

100 Serieswhat is in this family and where it ends

The smallest sizes in this family have an inside diameter smaller than their own cord is thick. A ring like that has very little left in the middle, and it exists because a family is numbered by cord and not by what looks sensible at the small end. The pages for those sizes print both numbers side by side, so the ratio is visible rather than merely odd.

This is also the family in which the tolerance on the inside diameter starts to grow with the size rather than staying at a single value, and the per-size figure is printed on each page rather than derived.

This is 77 dash numbers, from the -102 at 0.049 in (1.24 mm) inside diameter to the -178 at 9.737 in (247.32 mm). Every size in it carries a 0.103 in (2.62 mm) cord.

The numbering in this family is continuous across -102 to -178: there are no missing dash numbers inside the range.

2 sizes here have an inside diameter smaller than the cord is thick — the -102 (0.049 in inside on a 0.103 in cord) and the -103 (0.081 in inside on a 0.103 in cord).

All 77 sizesdash number, inside diameter, cord and tolerances

Dash	ID (in)	ID (mm)	Cord (in)	Cord (mm)	ID tol.	Cord tol.
-102	0.049	1.24	0.103	2.62	±0.005	±0.003
-103	0.081	2.06	0.103	2.62	±0.005	±0.003
-104	0.112	2.84	0.103	2.62	±0.005	±0.003
-105	0.143	3.63	0.103	2.62	±0.005	±0.003
-106	0.174	4.42	0.103	2.62	±0.005	±0.003
-107	0.206	5.23	0.103	2.62	±0.005	±0.003
-108	0.237	6.02	0.103	2.62	±0.005	±0.003
-109	0.299	7.59	0.103	2.62	±0.005	±0.003
-110	0.362	9.19	0.103	2.62	±0.005	±0.003
-111	0.424	10.77	0.103	2.62	±0.005	±0.003
-112	0.487	12.37	0.103	2.62	±0.005	±0.003
-113	0.549	13.94	0.103	2.62	±0.007	±0.003
-114	0.612	15.54	0.103	2.62	±0.009	±0.003
-115	0.674	17.12	0.103	2.62	±0.009	±0.003
-116	0.737	18.72	0.103	2.62	±0.009	±0.003
-117	0.799	20.29	0.103	2.62	±0.010	±0.003
-118	0.862	21.89	0.103	2.62	±0.010	±0.003
-119	0.924	23.47	0.103	2.62	±0.010	±0.003
-120	0.987	25.07	0.103	2.62	±0.010	±0.003
-121	1.049	26.64	0.103	2.62	±0.010	±0.003
-122	1.112	28.24	0.103	2.62	±0.010	±0.003
-123	1.174	29.82	0.103	2.62	±0.012	±0.003
-124	1.237	31.42	0.103	2.62	±0.012	±0.003
-125	1.299	32.99	0.103	2.62	±0.012	±0.003
-126	1.362	34.59	0.103	2.62	±0.012	±0.003
-127	1.424	36.17	0.103	2.62	±0.012	±0.003
-128	1.487	37.77	0.103	2.62	±0.012	±0.003
-129	1.549	39.34	0.103	2.62	±0.015	±0.003
-130	1.612	40.94	0.103	2.62	±0.015	±0.003
-131	1.674	42.52	0.103	2.62	±0.015	±0.003
-132	1.737	44.12	0.103	2.62	±0.015	±0.003
-133	1.799	45.69	0.103	2.62	±0.015	±0.003
-134	1.862	47.29	0.103	2.62	±0.015	±0.003
-135	1.925	48.9	0.103	2.62	±0.017	±0.003
-136	1.987	50.47	0.103	2.62	±0.017	±0.003
-137	2.050	52.07	0.103	2.62	±0.017	±0.003
-138	2.112	53.64	0.103	2.62	±0.017	±0.003
-139	2.175	55.25	0.103	2.62	±0.017	±0.003
-140	2.237	56.82	0.103	2.62	±0.017	±0.003
-141	2.300	58.42	0.103	2.62	±0.020	±0.003
-142	2.362	59.99	0.103	2.62	±0.020	±0.003
-143	2.425	61.6	0.103	2.62	±0.020	±0.003
-144	2.487	63.17	0.103	2.62	±0.020	±0.003
-145	2.550	64.77	0.103	2.62	±0.020	±0.003
-146	2.612	66.34	0.103	2.62	±0.020	±0.003
-147	2.675	67.95	0.103	2.62	±0.022	±0.003
-148	2.737	69.52	0.103	2.62	±0.022	±0.003
-149	2.800	71.12	0.103	2.62	±0.022	±0.003
-150	2.862	72.69	0.103	2.62	±0.022	±0.003
-151	2.987	75.87	0.103	2.62	±0.024	±0.003
-152	3.237	82.22	0.103	2.62	±0.024	±0.003
-153	3.487	88.57	0.103	2.62	±0.024	±0.003
-154	3.737	94.92	0.103	2.62	±0.028	±0.003
-155	3.987	101.27	0.103	2.62	±0.028	±0.003
-156	4.237	107.62	0.103	2.62	±0.030	±0.003
-157	4.487	113.97	0.103	2.62	±0.030	±0.003
-158	4.737	120.32	0.103	2.62	±0.030	±0.003
-159	4.987	126.67	0.103	2.62	±0.035	±0.003
-160	5.237	133.02	0.103	2.62	±0.035	±0.003
-161	5.487	139.37	0.103	2.62	±0.035	±0.003
-162	5.737	145.72	0.103	2.62	±0.035	±0.003
-163	5.987	152.07	0.103	2.62	±0.035	±0.003
-164	6.237	158.42	0.103	2.62	±0.040	±0.003
-165	6.487	164.77	0.103	2.62	±0.040	±0.003
-166	6.737	171.12	0.103	2.62	±0.040	±0.003
-167	6.987	177.47	0.103	2.62	±0.040	±0.003
-168	7.237	183.82	0.103	2.62	±0.045	±0.003
-169	7.487	190.17	0.103	2.62	±0.045	±0.003
-170	7.737	196.52	0.103	2.62	±0.045	±0.003
-171	7.987	202.87	0.103	2.62	±0.045	±0.003
-172	8.237	209.22	0.103	2.62	±0.050	±0.003
-173	8.487	215.57	0.103	2.62	±0.050	±0.003
-174	8.737	221.92	0.103	2.62	±0.050	±0.003
-175	8.987	228.27	0.103	2.62	±0.050	±0.003
-176	9.237	234.62	0.103	2.62	±0.055	±0.003
-177	9.487	240.97	0.103	2.62	±0.055	±0.003
-178	9.737	247.32	0.103	2.62	±0.055	±0.003

Inches are the standard’s own units; millimetre values are conversions — inch × 25.4, rounded to two decimals — and not the ISO 3601-1 metric sizes. Outside diameter is a reference value derived as ID + 2 × cross-section; the two diameters the standard fixes are the inside diameter and the cord.

Tolerances are the per-size figures the standard gives, not a value derived from the diameter — the same inside diameter can carry a different tolerance in a different series, and each page prints its own.

Reading a 1xx dash numberwhat the digits do and do not tell you

Every dash number in this family starts with the digit 1, which is what puts it here. The remaining two digits are its position in the family, counted upwards by inside diameter — they are not a size code, and nothing in them can be multiplied or read off to get a dimension. Two rings whose numbers differ by one can differ by a hundredth of an inch or by a quarter of one.

A cord family is named for the cord its sizes are built on, and the name is a fair description of every size in it only when the family has a single cord throughout. This one does — it carries 0.103 in (2.62 mm).

AS568-214ID 0.984 · cord 0.139 in