OSK™ Industrial Square Buna-N Square O-Ring Kit 18 Sizes 180 Pieces

Qty Discounts Prices
1-4 $24.230	5-24 $21.800	25-49 $20.850	50+ $16.680

$24.230

Model: K180X18SN70
29 in Stock

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180-Piece Square Ring Kit – Buna-N Nitrile NBR 70 Duro

Square-rings (also called Square O-Rings or Lathe Cut Washer Rings) are designed with a square cross-section and are fully interchangeable with standard AS568 O-Rings. They provide excellent sealing performance in standard O-Ring glands, often delivering enhanced stability against rolling or twisting in dynamic and static applications.

Made from Buna-N Nitrile (NBR) 70 durometer, black, these square-rings combine affordability with proven performance. NBR is one of the most widely used elastomers thanks to its excellent oil resistance, fuel resistance, and strong physical properties. This kit offers reliability, leak prevention, and reduced downtime in a wide range of industrial uses.

Operating temperature: -40° to +212°F (–40° to +100°C)

Material & Performance Details

Compound: Buna-N (NBR)
Durometer: 70 Shore A
Color: Black
Strengths: Oil resistance, fuel resistance, abrasion resistance, good tensile strength.
Limitations: Not recommended for prolonged outdoor exposure, direct sunlight, or ozone.

Chemical Compatibility:

Excellent resistance to: Petroleum oils, hydraulic fluids, water, silicone greases, and alcohols.
Limited capability with: Strong acids, brake fluids, phosphate esters.
Not compatible with: Ozone, weathering, and ketones (MEK, acetone).

Kit Contents – Sizes & Measurements

Each size is listed with:

AS568 Dash Number (Nominal Reference)
Inside Diameter (ID) in inches & millimeters
Outside Diameter (OD) in inches & millimeters
Cross Section (CS) in inches & millimeters

Square O-Ring Kit Includes:

10 pc -008 — 3/16" ID × 5/16" OD × 1/16" CS
Actual: 0.176" ID × 0.308" OD × 0.066" CS (4.47mm × 7.83mm × 1.68mm)
10 pc -009 — 7/32" ID × 11/32" OD × 1/16" CS
Actual: 0.208" ID × 0.340" OD × 0.066" CS (5.28mm × 8.64mm × 1.68mm)
12 pc -010 — 1/4" ID × 3/8" OD × 1/16" CS
Actual: 0.239" ID × 0.371" OD × 0.066" CS (6.07mm × 9.43mm × 1.68mm)
12 pc -011 — 5/16" ID × 7/16" OD × 1/16" CS
Actual: 0.301" ID × 0.433" OD × 0.066" CS (7.65mm × 11.01mm × 1.68mm)
12 pc -012 — 3/8" ID × 1/2" OD × 1/16" CS
Actual: 0.364" ID × 0.496" OD × 0.066" CS (9.25mm × 12.61mm × 1.68mm)
10 pc -013 — 7/16" ID × 9/16" OD × 1/16" CS
Actual: 0.426" ID × 0.558" OD × 0.066" CS (10.82mm × 14.18mm × 1.68mm)
10 pc -014 — 1/2" ID × 5/8" OD × 1/16" CS
Actual: 0.489" ID × 0.621" OD × 0.066" CS (12.42mm × 15.78mm × 1.68mm)
10 pc -015 — 9/16" ID × 11/16" OD × 1/16" CS
Actual: 0.551" ID × 0.683" OD × 0.066" CS (14.00mm × 17.36mm × 1.68mm)
10 pc -110 — 3/8" ID × 9/16" OD × 3/32" CS
Actual: 0.362" ID × 0.560" OD × 0.099" CS (9.19mm × 14.21mm × 2.51mm)
10 pc -111 — 7/16" ID × 5/8" OD × 3/32" CS
Actual: 0.424" ID × 0.622" OD × 0.099" CS (10.77mm × 15.79mm × 2.51mm)
10 pc -112 — 1/2" ID × 11/16" OD × 3/32" CS
Actual: 0.487" ID × 0.685" OD × 0.099" CS (12.37mm × 17.39mm × 2.51mm)
10 pc -113 — 9/16" ID × 3/4" OD × 3/32" CS
Actual: 0.549" ID × 0.747" OD × 0.099" CS (13.94mm × 18.96mm × 2.51mm)
10 pc -114 — 5/8" ID × 13/16" OD × 3/32" CS
Actual: 0.612" ID × 0.810" OD × 0.099" CS (15.54mm × 20.56mm × 2.51mm)
10 pc -115 — 11/16" ID × 7/8" OD × 3/32" CS
Actual: 0.674" ID × 0.872" OD × 0.099" CS (17.12mm × 22.14mm × 2.51mm)
10 pc -116 — 3/4" ID × 15/16" OD × 3/32" CS
Actual: 0.737" ID × 0.935" OD × 0.099" CS (18.72mm × 23.74mm × 2.51mm)
10 pc -117 — 13/16" ID × 1" OD × 3/32" CS
Actual: 0.799" ID × 0.997" OD × 0.099" CS (20.29mm × 25.32mm × 2.51mm)
7 pc -211 — 13/16" ID × 1-1/16" OD × 1/8" CS
Actual: 0.796" ID × 1.064" OD × 0.134" CS (20.22mm × 27.02mm × 3.40mm)
7 pc -212 — 7/8" ID × 1-1/8" OD × 1/8" CS
Actual: 0.859" ID × 1.127" OD × 0.134" CS (21.82mm × 28.62mm × 3.40mm)