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Custom O-rings and Shapes

Customized cross-section and diameter dimensions are available for shipment in just five working days. We make them to your order using our patented O-ring splicing technology.

Custom shapes are designed and molded to your specific requirements. Typical custom shapes include valve seats, diaphragms, gaskets, packer seals, T-seals, column fittings and more.

Custom parts and components with unusual geometries can be designed and molded in Kalrez® perfluoroelastomer parts to meet the needs of specific sealing applications. Examples include special profiles and rectangular-shaped seals for slit valves and windows: metal-bonded parts, profiled quartz tube seals, diaphragms, lip seals, hollow O-rings, tubing and other specialized configurations.

Kalrez® QS Spliced O-rings: The Quick-sealing Solution with Long-term Performance

Now, a patented splicing method created by DuPont Performance Elastomers enables quick production of O-rings that conform to most industry specifications or to your custom requirements. This exciting technology reduces the manufacturing time for spliced O-rings as well as the cost hurdles associated with custom O-rings. Whether your intended use is prototyping or large-scale commercialization, spliced O-rings deliver a quick-sealing solution with the well known performance of Kalrez® parts.

A Range of Sizes and Compounds to Meet Your Needs

You're no longer bound by industry standard sizes when you need the performance of Kalrez® parts. Kalrez® QS spliced O-rings can be produced in a broad range of customized cross-section and diameter dimensions to meet your specific needs. Cross sections are available within a range of .070" to .500" (1.78 mm to 12.7 mm), with any inside diameter not less than 6.000" (152.40mm). Spliced O-rings are currently available in several compounds, including Kalrez® 4079.

Outstanding Performance

Kalrez® is well known for its outstanding chemical resistance and thermal stability. Kalrez® QS O-rings demonstrate the chemical resistance of the base compound used for Kalrez® parts with thermal performance up to 260°C (500°F). For compounds with higher thermal capabilities, applications involving temperatures greater than 260°C (500°F) may be restricted to static seal designs. It is necessary that you understand your service requirements before selecting Kalrez® QS parts.

How to Specify Your Part

You can specify Kalrez® QS two ways; industry-standard reference or explicit inside diameter with cross-section dimensions. Kalrez® QS spliced O-rings can be produced according to several industry standards: SAE AS 568, ISO 3601, JIS B2401, or comparable O-ring standard.

Dimensional tolerances for Kalrez® QS are provided in the table below. Surface quality complies with MIL-STD-413C when applying the parting line requirements to the splice area. For other dimensional and surface specifications, contact your authorized Kalrez® distributor.

Inside Diameter:

Nominal Range
Nominal Range
6.000-6.550 ±.040 152.40-166.39 ±1.02
6.551-7.560 ±.045 166.40-192.03 ±1.14
7.561-8.610 ±.050 192.04-218.70 ±1.27
8.611-9.700 ±.055 218.71-246.39 ±1.40
9.701-11.400 ±.060 246.40-289.57 ±1.52
11.401-13.700 ±.070 289.58-347.99 ±1.78
13.701-16.100 ±.080 348.00-408.95 ±2.03
16.101-18.600 ±.090 408.96-472.45 ±2.29
18.601-22.500 ±.100 472.46-571.51 ±2.54
22.501-26.000 ±.120 571.52-660.40 ±3.05
26.001-larger ±0.5% 660.41-larger ±0.5%

Cross Section Diameter:

Nominal Range
Nominal Range
.070-.104 ±.003 1.78-2.65 ±.08
.105-.149 ±.004 2.66-3.80 ±.10
.150-.220 ±.005 3.81-5.60 ±.13
.221-.300 ±.006 5.61-7.64 ±.15
.301-.375 ±.007 7.65-9.55 ±.18
.376-.425 ±.008 9.56-10.81 ±.20
.426-.500 ±.009 10.81-12.70 ±.23

Examples of Kalrez® QS Part Call-out:

Call-out Product Description
Kalrez® 4079 QS AS568-444 Kalrez® 4079 QS Spliced O-Ring
7.725±.050" inside diameter (ID)
.275±.006" cross-section diameter (CSD)
Kalrez® 4079 QS
21.8" ID x .310" CSD
Kalrez® 4079 21.800±.100: ID x
.310±.007" QS Spliced O-Ring