Metric Buna O-Rings

OneMonroe’s Metric Buna O-Rings are engineered to provide reliable sealing performance across a variety of industrial and commercial applications. Made from high-quality Buna-N (Nitrile) rubber, these O-rings are known for their excellent resistance to oils, fuels, and other petroleum-based products, making them ideal for use in environments where durable, leak-proof seals are essential. Buna-N’s resilient properties allow it to maintain its integrity even in challenging temperatures, ranging from -40°F to 250°F, ensuring these O-rings can withstand both low and high-stress conditions with ease. With a broad range of metric sizes available, OneMonroe ensures you’ll find the right fit for your exact specifications.

Our Metric Buna O-Rings are crafted to offer outstanding resistance to abrasion and tearing, providing long-lasting performance in rigorous applications. This makes them well-suited for automotive, aerospace, marine, and hydraulic systems, as well as in general maintenance and repair settings. The unique chemical composition of Buna-N allows these O-rings to endure pressure and friction over extended periods without compromising their sealing capabilities, making them a reliable choice for static and dynamic sealing tasks. Each O-ring is manufactured to precise industry standards, ensuring a dependable fit and function in every installation.

With OneMonroe, you’re getting more than just a product; you’re receiving a commitment to quality and expertise. Our team is dedicated to supporting your projects with high-quality metric Buna O-Rings that meet both industry standards and specific customer requirements. We provide technical support to help you select the best O-ring for your application, offering detailed product specifications and guidance. Trust OneMonroe to deliver durable, efficient, and cost-effective sealing solutions tailored to meet the demands of your unique projects.

For more information, please see: Comparison Properties Chart, PTFE Encapsulated O-rings, Material Shelf Life, and O-ring Groove Design Chart.

Item #	IntegrationID	Type	Material	Cross Reference	Cross Section Width	Durometer	Inside Diameter	Product Guides
33 X 4 B-90	N/A 121320	N/A Metric Standard O-Ring	N/A Buna	N/A	N/A 4.00 mm	N/A 90	N/A 33.00 mm	N/A Seal Guides
33.5 X 4 B-70	N/A 121321	N/A Metric Standard O-Ring	N/A Buna	N/A V34	N/A 4.00 mm	N/A 70	N/A 33.50 mm	N/A Seal Guides
33.5 X 4 B-90	N/A 121322	N/A Metric Standard O-Ring	N/A Buna	N/A V34	N/A 4.00 mm	N/A 90	N/A 33.50 mm	N/A Seal Guides
34x4.00B70	N/A 121323	N/A Metric Standard O-Ring	N/A Buna	N/A	N/A 4.00 mm	N/A 70	N/A 34.00 mm	N/A Seal Guides
34 X 4 B-90	N/A 121324	N/A Metric Standard O-Ring	N/A Buna	N/A	N/A 4.00 mm	N/A 90	N/A 34.00 mm	N/A Seal Guides
35x4.00B70	N/A 121325	N/A Metric Standard O-Ring	N/A Buna	N/A	N/A 4.00 mm	N/A 70	N/A 35.00 mm	N/A Seal Guides
35 X 4 B-90	N/A 121326	N/A Metric Standard O-Ring	N/A Buna	N/A	N/A 4.00 mm	N/A 90	N/A 35.00 mm	N/A Seal Guides
36x4.00B70	N/A 121327	N/A Metric Standard O-Ring	N/A Buna	N/A	N/A 4.00 mm	N/A 70	N/A 36.00 mm	N/A Seal Guides
36 X 4 B-90	N/A 121328	N/A Metric Standard O-Ring	N/A Buna	N/A	N/A 4.00 mm	N/A 90	N/A 36.00 mm	N/A Seal Guides
37x4.00B70	N/A 121329	N/A Metric Standard O-Ring	N/A Buna	N/A	N/A 4.00 mm	N/A 70	N/A 37.00 mm	N/A Seal Guides
37 X 4 B-90	N/A 121330	N/A Metric Standard O-Ring	N/A Buna	N/A	N/A 4.00 mm	N/A 90	N/A 37.00 mm	N/A Seal Guides
38x4.00B70	N/A 121331	N/A Metric Standard O-Ring	N/A Buna	N/A	N/A 4.00 mm	N/A 70	N/A 38.00 mm	N/A Seal Guides
38 X 4 B-90	N/A 121332	N/A Metric Standard O-Ring	N/A Buna	N/A	N/A 4.00 mm	N/A 90	N/A 38.00 mm	N/A Seal Guides
39x4.00B70	N/A 121333	N/A Metric Standard O-Ring	N/A Buna	N/A	N/A 4.00 mm	N/A 70	N/A 39.00 mm	N/A Seal Guides
39 X 4 B-90	N/A 121334	N/A Metric Standard O-Ring	N/A Buna	N/A	N/A 4.00 mm	N/A 90	N/A 39.00 mm	N/A Seal Guides
39.5 X 4 B-70	N/A 121335	N/A Metric Standard O-Ring	N/A Buna	N/A V40	N/A 4.00 mm	N/A 70	N/A 39.50 mm	N/A Seal Guides
39.5 X 4 B-90	N/A 121336	N/A Metric Standard O-Ring	N/A Buna	N/A V40	N/A 4.00 mm	N/A 90	N/A 39.50 mm	N/A Seal Guides
40x4.00B70	N/A 121337	N/A Metric Standard O-Ring	N/A Buna	N/A	N/A 4.00 mm	N/A 70	N/A 40.00 mm	N/A Seal Guides
40 X 4 B-90	N/A 121338	N/A Metric Standard O-Ring	N/A Buna	N/A	N/A 4.00 mm	N/A 90	N/A 40.00 mm	N/A Seal Guides
41x4.00B70	N/A 121339	N/A Metric Standard O-Ring	N/A Buna	N/A	N/A 4.00 mm	N/A 70	N/A 41.00 mm	N/A Seal Guides
41 X 4 B-90	N/A 121340	N/A Metric Standard O-Ring	N/A Buna	N/A	N/A 4.00 mm	N/A 90	N/A 41.00 mm	N/A Seal Guides
42x4.00B70	N/A 121341	N/A Metric Standard O-Ring	N/A Buna	N/A	N/A 4.00 mm	N/A 70	N/A 42.00 mm	N/A Seal Guides
42 X 4 B-90	N/A 121342	N/A Metric Standard O-Ring	N/A Buna	N/A	N/A 4.00 mm	N/A 90	N/A 42.00 mm	N/A Seal Guides
43x4.00B70	N/A 121343	N/A Metric Standard O-Ring	N/A Buna	N/A	N/A 4.00 mm	N/A 70	N/A 43.00 mm	N/A Seal Guides
43 X 4 B-90	N/A 121344	N/A Metric Standard O-Ring	N/A Buna	N/A	N/A 4.00 mm	N/A 90	N/A 43.00 mm	N/A Seal Guides

N/A
121320

N/A Metric Standard O-Ring

N/A Buna

N/A

N/A 4.00 mm

N/A 90

N/A 33.00 mm

N/A Seal Guides

33.5 X 4 B-70

N/A
121321

N/A Metric Standard O-Ring

N/A Buna

N/A V34

N/A 4.00 mm

N/A 70

N/A 33.50 mm

N/A Seal Guides

33.5 X 4 B-90

N/A
121322

N/A Metric Standard O-Ring

N/A Buna

N/A V34

N/A 4.00 mm

N/A 90

N/A 33.50 mm

N/A Seal Guides

34x4.00B70

N/A
121323

N/A Metric Standard O-Ring

N/A Buna

N/A

N/A 4.00 mm

N/A 70

N/A 34.00 mm

N/A Seal Guides

34 X 4 B-90

N/A
121324

N/A Metric Standard O-Ring

N/A Buna

N/A

N/A 4.00 mm

N/A 90

N/A 34.00 mm

N/A Seal Guides

35x4.00B70

N/A
121325

N/A Metric Standard O-Ring

N/A Buna

N/A

N/A 4.00 mm

N/A 70

N/A 35.00 mm

N/A Seal Guides

35 X 4 B-90

N/A
121326

N/A Metric Standard O-Ring

N/A Buna

N/A

N/A 4.00 mm

N/A 90

N/A 35.00 mm

N/A Seal Guides

36x4.00B70

N/A
121327

N/A Metric Standard O-Ring

N/A Buna

N/A

N/A 4.00 mm

N/A 70

N/A 36.00 mm

N/A Seal Guides

36 X 4 B-90

N/A
121328

N/A Metric Standard O-Ring

N/A Buna

N/A

N/A 4.00 mm

N/A 90

N/A 36.00 mm

N/A Seal Guides

37x4.00B70

N/A
121329

N/A Metric Standard O-Ring

N/A Buna

N/A

N/A 4.00 mm

N/A 70

N/A 37.00 mm

N/A Seal Guides

37 X 4 B-90

N/A
121330

N/A Metric Standard O-Ring

N/A Buna

N/A

N/A 4.00 mm

N/A 90

N/A 37.00 mm

N/A Seal Guides

38x4.00B70

N/A
121331

N/A Metric Standard O-Ring

N/A Buna

N/A

N/A 4.00 mm

N/A 70

N/A 38.00 mm

N/A Seal Guides

38 X 4 B-90

N/A
121332

N/A Metric Standard O-Ring

N/A Buna

N/A

N/A 4.00 mm

N/A 90

N/A 38.00 mm

N/A Seal Guides

39x4.00B70

N/A
121333

N/A Metric Standard O-Ring

N/A Buna

N/A

N/A 4.00 mm

N/A 70

N/A 39.00 mm

N/A Seal Guides

39 X 4 B-90

N/A
121334

N/A Metric Standard O-Ring

N/A Buna

N/A

N/A 4.00 mm

N/A 90

N/A 39.00 mm

N/A Seal Guides

39.5 X 4 B-70

N/A
121335

N/A Metric Standard O-Ring

N/A Buna

N/A V40

N/A 4.00 mm

N/A 70

N/A 39.50 mm

N/A Seal Guides

39.5 X 4 B-90

N/A
121336

N/A Metric Standard O-Ring

N/A Buna

N/A V40

N/A 4.00 mm

N/A 90

N/A 39.50 mm

N/A Seal Guides

40x4.00B70

N/A
121337

N/A Metric Standard O-Ring

N/A Buna

N/A

N/A 4.00 mm

N/A 70

N/A 40.00 mm

N/A Seal Guides

40 X 4 B-90

N/A
121338

N/A Metric Standard O-Ring

N/A Buna

N/A

N/A 4.00 mm

N/A 90

N/A 40.00 mm

N/A Seal Guides

41x4.00B70

N/A
121339

N/A Metric Standard O-Ring

N/A Buna

N/A

N/A 4.00 mm

N/A 70

N/A 41.00 mm

N/A Seal Guides

41 X 4 B-90

N/A
121340

N/A Metric Standard O-Ring

N/A Buna

N/A

N/A 4.00 mm

N/A 90

N/A 41.00 mm

N/A Seal Guides

42x4.00B70

N/A
121341

N/A Metric Standard O-Ring

N/A Buna

N/A

N/A 4.00 mm

N/A 70

N/A 42.00 mm

N/A Seal Guides

42 X 4 B-90

N/A
121342

N/A Metric Standard O-Ring

N/A Buna

N/A

N/A 4.00 mm

N/A 90

N/A 42.00 mm

N/A Seal Guides

43x4.00B70

N/A
121343

N/A Metric Standard O-Ring

N/A Buna

N/A

N/A 4.00 mm

N/A 70

N/A 43.00 mm

N/A Seal Guides

43 X 4 B-90

N/A
121344

N/A Metric Standard O-Ring

N/A Buna

N/A

N/A 4.00 mm

N/A 90

N/A 43.00 mm

N/A Seal Guides