<h2>5-Pack Black NBR O-Rings – Oil-Resistant Nitrile Rubber Gasket Washers</h2> <p>Keep your machinery, plumbing, and hydraulic systems leak-free with these heavy-duty <strong>Nitrile Butadiene Rubber (NBR) O-Rings</strong>. Each pack includes <strong>5 precision-formed ring gaskets</strong> with a cross-section of <strong>4 mm</strong> and outer diameters ranging from <strong>52 mm to 100 mm</strong>. Engineered for demanding industrial and domestic applications, these standard O-rings deliver a reliable, long-lasting seal wherever you need it.</p> <p><em>Made in Mainland China.</em></p> <h3>Why Choose These NBR O-Rings?</h3> <ul> <li> <strong>Oil &amp; Fuel Resistant:</strong> NBR rubber maintains its integrity when exposed to petroleum-based oils, fuels, and hydraulic fluids — ideal for high-demand sealing environments.</li> <li> <strong>Wide Temperature Range:</strong> Performs consistently across a broad range of operating temperatures, making it suitable for both hot and cold fluid systems.</li> <li> <strong>Durable Nitrile Material:</strong> Resistant to abrasion, compression set, and general wear — built to outlast standard rubber seals.</li> <li> <strong>Standard Sizing:</strong> CS 4 mm cross-section with OD options from 52 mm to 100 mm for compatibility with a wide variety of fittings and assemblies.</li> <li> <strong>Versatile Application:</strong> Perfect for machinery, plumbing lines, hydraulic cylinders, pneumatic systems, automotive components, and more.</li> <li> <strong>Value Pack:</strong> Comes in a convenient 5-piece lot — great for repairs, maintenance, or keeping on hand as replacements.</li> </ul> <h3>Product Specifications</h3> <table> <tbody> <tr> <td><strong>Material</strong></td> <td>Nitrile Butadiene Rubber (NBR)</td> </tr> <tr> <td><strong>Color</strong></td> <td>Black</td> </tr> <tr> <td><strong>Cross-Section (CS)</strong></td> <td>4 mm</td> </tr> <tr> <td><strong>Outer Diameter (OD)</strong></td> <td>52 mm – 100 mm (select your size)</td> </tr> <tr> <td><strong>Shape</strong></td> <td>Ring Gasket</td> </tr> <tr> <td><strong>Quantity</strong></td> <td>5 Pieces per Pack</td> </tr> <tr> <td><strong>Standard</strong></td> <td>Standard</td> </tr> <tr> <td><strong>Origin</strong></td> <td>Mainland China</td> </tr> </tbody> </table> <h3>Common Applications</h3> <ul> <li>Hydraulic &amp; pneumatic cylinder sealing</li> <li>Plumbing pipe joints and fittings</li> <li>Industrial machinery and equipment</li> <li>Automotive fluid systems and pumps</li> <li>Water treatment and filtration systems</li> </ul> <h3>Related Products You May Like</h3> <ul> <li><a href="/products/10pcs-2-pin-quick-splice-spring-wire-connectors-lock-terminals">10pcs 2-Pin Spring Wire Connectors – Quick Splice Lock Terminals</a></li> <li><a href="/products/stainless-steel-self-tapping-screws-m2-2-m4-8-phillips-wood-hinge">10PCS Stainless Steel Self-Tapping Screws M2.2–M4.8 Phillips</a></li> <li><a href="/products/12pcs-16mm-momentary-push-button-switch-1no-metal-2-pin-self-reset">12pcs 16mm Momentary Push Button Switch 1NO Metal 2-Pin Self-Reset</a></li> </ul> <p>Learn more: <a href="https://www.osha.gov/hand-power-tools" target="_blank" rel="noopener">OSHA guidance on hand and power tools</a></p> <h3>Frequently Asked Questions</h3> <h4>Q: What size O-rings are included in this pack?</h4> <p>A: This pack contains 5 black NBR O-rings with a cross-section (CS) of 4 mm. The outer diameter (OD) ranges from 52 mm to 100 mm depending on the specific size variant you select. Please choose your required OD size before ordering.</p> <h4>Q: Are these O-rings suitable for use with hydraulic oil and petroleum fluids?</h4> <p>A: Yes. These O-rings are made from Nitrile Butadiene Rubber (NBR), which is specifically formulated to resist petroleum-based oils, hydraulic fluids, and fuels, making them an excellent choice for hydraulic, pneumatic, and automotive sealing applications.<