Fast FFKM O-rings in AS568, JIS, and Metric Sizes: Canrez® vs Kalrez® vs Chemraz® for High-End Sealing

If you work in semiconductor, chemical processing, or oil and gas, you already know the pattern: one “simple” O-ring turns into a schedule risk. The elastomer needs to survive aggressive chemistries, high temperature, plasma exposure, sour service, or rapid pressure cycling. The size needs to match a standard like AS568, JIS B 2401, or common metric O-ring dimensions. And you need the part number in your hands quickly, not weeks or months from now.

That is exactly why Canyon Components built a broad, practical FFKM perfluoroelastomer offering focused on real-world lead times. For a wide range of standard AS568 -XXX part numbers, JIS B 2401 sizes, and common metric sizes, we can typically supply O-rings in 1 to 2 weeks in a curated set of high-demand compounds. There are more sizes and more materials available, but in this post we are focusing on the compounds customers most commonly request when they are comparing Canrez®, Kalrez®, and Chemraz®.

Below we will break down how to think about compound selection, how standards like AS568 and JIS B 2401 affect your part number strategy, and where each of these FFKM families fits best for O-rings, gaskets, and custom rubber parts.

Why FFKM Perfluoroelastomer Matters for O-rings, Gaskets, and Custom Rubber Parts

FFKM (perfluoroelastomer) is often selected when other elastomer options hit a wall. In broad terms, FFKM is chosen for:

• Exceptional chemical resistance across a very wide range of fluids
• High-temperature capability compared to many elastomer families
• Long service life in aggressive processes where downtime is expensive
• Compatibility across mixed chemistries, especially in chemical processing
• Specialized performance options like low temperature, low compression set, plasma resistance, or anti-explosive decompression (AED) performance depending on compound design

In practical sealing applications, FFKM helps reduce the total number of elastomer materials you need to stock, especially when you are supporting multiple lines, multiple chemicals, or multiple customer specifications. That translates into fewer surprises, fewer emergency buys, and fewer “close enough” substitutions that create reliability issues later.

This is true whether you are sealing with O-rings, flat gaskets, or custom rubber parts like diaphragms and special profiles.

Sizing Standards: AS568, JIS B 2401, and Metric O-rings

Before you even choose a compound, you need to choose a sizing standard that matches your hardware and your maintenance workflow.

AS568 and AS568 -XXX part numbers

AS568 is the most common O-ring size standard used in North America. It is often referenced as AS568 -XXX (for example, AS568-214). In many maintenance programs, the part number is synonymous with the size. That makes AS568 a common standard for equipment builders, MRO teams, and distributors.

JIS B 2401 sizes

JIS B 2401 is widely used for Japanese equipment and globally exported machinery. Many customers use JIS sizes because that is what is in the drawing package, the legacy BOM, or the OEM service manual. If you support pump systems, valves, automation equipment, and imported machinery, you will see JIS O-ring sizes constantly.

Metric O-ring sizes

Metric O-rings are common across Europe and in globally sourced equipment. In practice, “metric” can mean many different nominal standards, so clear dimensional callouts matter. If you are migrating from a brand part number to a dimensional standard, you want to document ID, cross-section, tolerance, and groove conditions so the elastomer and hardware design stay aligned.

The key point for reliability

The best compound in the world cannot fix a size mismatch. O-ring performance depends on correct squeeze, stretch, volume fill, extrusion gap control, and surface finish. That is why combining fast availability of the right standard size with the right FFKM perfluoroelastomer compound is such a big deal.

Continuously Molded Canrez FFKM O-rings and Seals

For large diameters, oversized glands, or non-standard geometries where an AS568, JIS B 2401, or metric O-ring is not available, continuously molded Canrez FFKM provides an effective solution that maintains the chemical resistance and temperature capability of a true perfluoroelastomer. Continuously molded construction allows for large-diameter O-rings, gasket-style rings, and other custom rubber parts with consistent sealing performance around the full circumference, helping reduce leak paths in static flanges, chambers, and vacuum systems. This approach enables you to standardize on your preferred Canrez FFKM elastomer family while accommodating unique dimensions, without sacrificing high-performance sealing in chemical processing, semiconductor, or oil and gas applications.

Custom Molded Canrez FFKM Parts

When a standard O-ring or continuously molded gasket cannot meet the design requirements, custom molded Canrez FFKM parts offer a tailored solution for complex sealing geometries such as custom O-rings, gaskets, custom parts, diaphragms, valve seats, lip seals, and specialty profiles. These custom rubber parts leverage the broad chemical resistance and high-temperature performance of FFKM perfluoroelastomer while allowing precise control over hardness, compression set, and dimensional tolerances to match demanding service environments. By aligning compound selection and molding processes with your chemical exposure, temperature range, and hardware design, custom molded Canrez components deliver the same reliability expected from high-performance FFKM O-rings and gaskets in critical applications.

The Compounds We Are Highlighting in This Blog

This blog focuses on specific, frequently requested compounds for high-end sealing programs and comparisons.

If you are sourcing AS568 O-ring sizes, JIS B 2401 O-rings, or metric O-rings, these compounds cover a wide spread of real applications: general purpose chemical processing, broader chemical resistance, higher temperature resistance, low temperature sealing, semiconductor dry processing and plasma environments, steam and amines, and oil and gas AED-focused sealing.

Quick Reference Table: Typical Properties and Temperature Ranges

Below is a simplified snapshot using the data you provided. Always confirm final selection against your actual chemicals, temperatures, pressures, and seal design.

How to Choose Between Canrez®, Kalrez®, and Chemraz® for Your O-ring Program

A lot of “brand vs brand” comparisons fail because they ignore what actually drives seal success. In most sealing programs, the decision comes down to five factors:

1. Chemical set (single chemical vs mixed streams, solvents, acids, caustics, amines, steam)
2. Temperature profile (steady state, spikes, cycling, bake-outs)
3. Mechanical needs (compression set targets, extrusion risk, hardness requirements)
4. Contamination risk (semiconductor and high purity processes)
5. Supply chain reality (lead time, standard size availability, consistency)

The Real Differentiator: Standard Sizes in 1 to 2 Weeks

For many customers, the biggest problem is not identifying the ideal perfluoroelastomer on paper. It is getting the right AS568 O-ring, JIS B 2401 O-ring, or metric O-ring in time to support production, maintenance, or a shutdown window.

That is why this blog focuses on the intersection of:

• High-demand FFKM compounds (Canrez, Kalrez, Chemraz families)
• High-demand standard sizes (AS568 -XXX, JIS B 2401, metric)
• Practical lead times, often 1 to 2 weeks for the highlighted scope

If you are building an O-ring and gasket program around FFKM, speed matters. Fast access reduces the temptation to substitute a less compatible elastomer, reduces downtime risk, and makes it easier to standardize to a smaller set of high-performance compounds.

A Practical Selection Guide for Engineers and Buyers

If you want a quick starting point, here are practical “selection buckets” based on the compounds in this post.

If you want a broad, general-purpose FFKM perfluoroelastomer

• Kalrez 4079
• Kalrez 6375
• Chemraz 505
• Canrez CP75BK01

If you need high temperature headroom and compression set performance

• Kalrez 7075
• Chemraz 555
• Canrez CP75BK20

If low temperature sealing is a major driver

• Kalrez 0040
• Chemraz 505 or 510 (depending on pressure and hardness needs)
• Canrez CP75BK91

If semiconductor dry processing and plasma resistance are central

• Chemraz 520
• Canrez CP70BK03 or CP75BK01 depending on chemistries and temperature

If oil and gas AED and standards alignment are central

• Canrez CP90BK01 (NACE TM0297 and NORSOK M-710 emphasis)

Closing: Build a Faster, Cleaner FFKM O-ring Program

FFKM perfluoroelastomer sealing is not just about buying a premium compound. It is about building a repeatable, documented program that supports your AS568 -XXX, JIS B 2401, and metric sizes without constant emergency sourcing. When your O-ring, gasket, and custom rubber parts program can rely on predictable supply, you reduce downtime risk and improve seal consistency across your equipment.

If you are comparing Canrez, Kalrez, and Chemraz for standard sizes, we can help you map your application requirements to the right compound family, confirm temperature limits, and align on chemical exposure and any special performance needs like steam, amines, plasma resistance, or AED.

Common relevant keywords

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