#008 Nitrile O-Rings (100 Pack) - Buna-N NBR 70A - 3/16" ID x 5/16" OD x 1/16" CS
Price per piece by quantity
- 1–49 pcs$6.44
- 50+ pcs$5.80
- 500+ pcs$5.15
- 1,000+ pcs$4.51
- 2,500+ pcs$3.86
- 5,000+ pcs$3.22
Bulk Discounts
| Quantity | Discounted price |
|---|---|
| Buy 1 – 49 pcs | $6.44 /each |
| Buy 50 – 499 pcs | $5.80 /each |
| Buy 500 – 999 pcs | $5.15 /each |
| Buy 1000 – 2499 pcs | $4.51 /each |
| Buy 2500 – 4999 pcs | $3.86 /each |
| Buy 5000 + pcs | $3.22 /each |
Need 5,000+ pieces or a recurring order? Request a bulk quote
#008 Nitrile O-Rings (100 Pack) - Buna-N NBR 70A - 3/16" ID x 5/16" OD x 1/16" CS is backordered and will ship as soon as it is back in stock.
Sizing help: O-ring size chart Shop all Rubber O-Rings Inch ↔ mm converter
Couldn't load pickup availability
- Usually ships within 24 hours from Elgin, SC (shipping policy)
- UPS or FedEx with a tracking number on every order
- Returns accepted up to 30 days after delivery (return policy)
- Bulk discounts by quantity, quotes for large orders (request a quote)
- ID
- 3/16"
- OD
- 5/16"
Need more than one size?
-
4 × $6.44
- 4 × $5.94
- 5 × $4.57
- 4 × $6.39
Each line starts at the $20.00-per-item minimum; Bulk Discounts tiers apply by quantity.
Description
Description
#008 Nitrile O-Ring (Buna-N NBR, 70A) - 3/16" ID x 5/16" OD x 1/16" CS
Standard AS568 dash size #008 nitrile O-ring - the exact size used across faucets, pumps, filters, and fittings worldwide. Sold as a pack of 100 so you have spares on hand for every rebuild.
Availability: Ships around Nov 2 (in transit from our supplier). You can order now; your order ships as soon as this size arrives at our warehouse.
Specifications
- AS568 Dash Number: -008
- Inside Diameter: 3/16" nominal (0.176" / 4.47 mm actual)
- Outside Diameter: 5/16" nominal (0.316" / 8.03 mm)
- Cross Section (Width): 1/16" (0.070" / 1.78 mm)
- Material: Nitrile rubber (Buna-N / NBR)
- Hardness: 70A durometer
- Temperature Range: -40°F to 250°F
- Color: Black | Pack of 100
Material - Why Buna-N Nitrile
Buna-N is the workhorse O-ring compound: excellent resistance to petroleum oils, fuels, hydraulic fluids, water, and silicone greases, with good abrasion and tear resistance. Not recommended for ozone/direct sunlight exposure, brake fluid, ketones, or strong acids - for those, use EPDM or Viton.
Common Applications
Carburetor and fuel fittings, small valve stems, pneumatic fittings, pressure washer nozzles and small hydraulic fittings. Nitrile handles gasoline and methanol well.
How to Measure an O-Ring
Measure the inside diameter (hole to hole) and the cross-section thickness of your old ring, or measure the groove: groove inner diameter = O-ring ID, groove width slightly wider than the cross section. Match both numbers to the chart below - the dash number takes care of the rest.
AS568 O-Ring Size Chart - Sizes We Stock
| Dash # | Inside Dia. | Outside Dia. | Cross Section | Metric ID |
|---|---|---|---|---|
| #008 (this size) | 3/16" (0.176") | 5/16" | 1/16" (0.070") | 4.47 mm ID |
| #010 | 1/4" (0.239") | 3/8" | 1/16" (0.070") | 6.07 mm ID |
| #011 | 5/16" (0.301") | 7/16" | 1/16" (0.070") | 7.65 mm ID |
| #012 | 3/8" (0.364") | 1/2" | 1/16" (0.070") | 9.25 mm ID |
| #014 | 1/2" (0.489") | 5/8" | 1/16" (0.070") | 12.42 mm ID |
| #017 | 11/16" (0.676") | 13/16" | 1/16" (0.070") | 17.17 mm ID |
| #110 | 3/8" (0.362") | 9/16" | 3/32" (0.103") | 9.19 mm ID |
| #112 | 1/2" (0.487") | 11/16" | 3/32" (0.103") | 12.37 mm ID |
| #121 | 1-1/16" (1.046") | 1-1/4" | 3/32" (0.103") | 26.57 mm ID |
| #210 | 3/4" (0.734") | 1" | 1/8" (0.139") | 18.64 mm ID |
| #214 | 1" (0.984") | 1-1/4" | 1/8" (0.139") | 24.99 mm ID |
| #228 | 2-1/4" (2.234") | 2-1/2" | 1/8" (0.139") | 56.74 mm ID |
| #230 | 2-1/2" (2.484") | 2-3/4" | 1/8" (0.139") | 63.09 mm ID |
| #238 | 3-1/2" (3.484") | 3-3/4" | 1/8" (0.139") | 88.49 mm ID |
| #357 | 5-1/2" (5.475") | 5-7/8" | 3/16" (0.210") | 139.06 mm ID |
Why Buy From Rubberfeetwarehouse
Genuine 70A Buna-N, ships from our South Carolina warehouse. Need a different size or larger quantity? Contact us.
Buna-N Material Guide
Buna-N Material Guide
Buna-N (Nitrile/NBR) 70A: excellent with petroleum oils, fuels, water, and hydraulic fluids. -40F to 250F. Not for ozone, brake fluid, or ketones - ask us about EPDM or Viton for those.
Delivery and Shipping
Delivery and Shipping
Usually ships within 24 hours from our South Carolina warehouse. All orders include tracking.
#008 Nitrile O-Rings (100 Pack) - Buna-N NBR 70A - 3/16" ID x ...
$6.44 each
O-Ring Specifications
| Inside Diameter | 3/16" (4.76 mm) |
|---|---|
| Outside Diameter | 5/16" (7.94 mm) |
| Cross Section / Width | 1/16" (1.59 mm) |
| SKU | ORING008100PCS |
AS568 nominal dimensions. Measure your groove ID and cross section to confirm fit.
Size & fit guide
| Label | Dimension | Size |
|---|---|---|
| A | Inside diameter | 3/16" 4.8 mm |
| B | Outside diameter | 5/16" 7.9 mm |
| C | Cross section | 1/16" 1.6 mm |
Schematic, not to scale. Sizes are nominal.
How to install
Wipe the groove clean and apply a thin film of silicone grease before seating the ring - it prevents pinching and doubles seal life on anything that gets opened regularly, like filter housings.
O-Ring Size Calculator
Enter your O-ring's inside diameter and cross-section — get the outside diameter and recommended static groove dimensions (25% squeeze).
Measuring a worn ring? Use calipers on ID and thickness — not the stretched old ring. Compound questions: rubber compatibility chart.
Frequently Asked Questions
How do I measure an O-ring?
Measure the inside diameter and the cross-section thickness of your old ring, or measure the groove: groove ID equals O-ring ID. Match both to the AS568 chart on this page.
Is Buna-N right for my application?
Buna-N (nitrile) handles petroleum oils, fuels, water, and hydraulic fluid from -40F to 250F. It is not for ozone/direct sun, brake fluid, or ketones - ask us about EPDM or Viton for those.
Should I lubricate O-rings at install?
Yes - a thin film of silicone grease prevents pinching and roughly doubles seal life on housings that get opened regularly, like water filter sumps.
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