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Materials · Compound Selection Guide

The right polymer for the job.

Six base elastomers, over 1000 custom formulations mixed and tested in-house. Choosing the right polymer is the single biggest factor in a long-lasting, failure-proof component. This page tells you how we choose.

Not sure? Skip the theory: message us on WhatsApp or email us, and we'll recommend the grade.

LET’S FIND YOUR COMPOUND

Tell us what your rubber needs to do.

Three quick steps. We’ll help you choose the material.

  1. 1Temperature
  2. 2Exposure
  3. 3Requirements
  4. 4Send
Step 1 of 3 · Temperature

What temperatures will it face?

Set the coldest and hottest temperatures. You can type a value or use the sliders.

°C
°C
Not sure? That’s what we’re here for.
SERVICE TEMPERATURE

Temperature ranges at a glance

Cold in blue, heat in orange. Compare the indicative ranges below.

Silicone-60°C to +225°C
EPDM-50°C to +110°C
FKM-30°C to +230°C
NBR-40°C to +110°C
CR-40°C to +110°C
SBR-40°C to +90°C

Indicative ranges. Confirm the compound grade and operating conditions with us.

OUTDOOR PERFORMANCE

Same exposure.
Different response.

Sun and rain cycle over small rubber test samples. See the differences in seconds.

Sun. Rain. Repeat.Outdoor weathering
Sun exposure
SBRLowerresistance
NBRLowerresistance
CRModerateresistance
EPDMHighresistance
SiliconeHighresistance
FKMHighresistance

Illustrative comparison, not a service-life prediction or test result. Actual performance depends on compound formulation and exposure conditions.

Side by Side

Full Property Chart

Scroll across to compare all six materials →

Property NBR (Nitrile) CR (Neoprene) EPDM Silicone (VMQ) FKM (Viton®) SBR
Hardness (°Shore A) 30-95 35-95 35-85 20-90 55-90 40-90
Temperature Range (°C) -40 to 110 -40 to 110 -50 to 110 -60 to 225 -30 to 230 -40 to 90
Electrical Resistance Poor Good Good Best Good Fair
Abrasion Resistance Excellent Poor Good Fair Excellent Excellent
Oil / Acid / Petrol Resistance Excellent Fair Poor (Good with acids) Oils Poor, Acids Good Excellent Poor
Weather & Ozone Resistance Very Poor Good Very Good Best Good Poor
Steam Resistance Poor Fair Best Good to 121°C Limited (special grades good) Poor

Viton® is a registered trademark. Figures are indicative. Tell us your operating conditions and we'll recommend the right polymer.

Silicone

VMQ / Silicone Rubber

Our speciality, from very soft 30 Shore A extrusions to silicone sponge. Grades built to FDA 21 CFR 177.2600, BfR XV and USP Class VI (ch 87 and 88) for food, beverage and pharma service.

Engineer's note

Brilliant across temperature, from deep cold to real heat, and clean enough for food and medical. Compression set is excellent, so seals stay springy and keep sealing for years. Two honest cautions: it tears and abrades more easily than most, and it is very hard to bond or glue. If physical strength is also a requirement, let us know. Special grades can handle it.

LED Luminaires Food & Pharma Tubing Medical Housings Electronics Enclosures Oven & Autoclave Seals
Continuous Service-60°C to +225°C
Short-Term Peak+300°C short-term (special grade)
Compression SetExcellent
ASTM D2000M2GE
Relative Cost●●●●○
Recommended for
UV & ozone Hot air Water Steam to 121°C Fungus
Keep away from
Fuels Mineral oils Superheated steam Solvents

EPDM

Ethylene Propylene Diene Monomer

Handles steam and hot water better than most elastomers, resists temperature cycling, and does it at a very competitive cost. The default choice for outdoor enclosure seals, pipe gaskets and potable water applications.

Engineer's note

Nothing beats it outdoors. Sun, ozone, rain, years of it, and EPDM shrugs it all off. Just keep it away from oil and fuel. That is the one thing it cannot take.

Outdoor Enclosures Potable Water (BS 6920) Solar & Street Lighting Automotive Weatherstrip
Continuous Service-50°C to +110°C
Short-Term Peak+150°C short-term
Compression SetGood
ASTM D20002CA
Relative Cost●●○○○
Recommended for
Sunlight Ozone Steam Hot water Weak acids
Keep away from
Mineral oils Fuels Solvents Grease

FKM

Fluoroelastomer (Viton®)

The premium polymer for aggressive environments: fuels, mineral oils, hydraulic fluids, acids and continuous high heat. Where NBR gives up, FKM keeps sealing. Not for ketones, esters or amines, and standard grades dislike steam. FDA and USP Class VI compliant FKM grades are available for food and pharma duty.

Engineer's note

Heat, no problem. Oil, no problem. Fuel, no problem. The one catch: if your fuel has ethanol in it, standard Viton swells. Ask for the flex-fuel terpolymer grade (E20, E50, E85) and you're covered.

Fuel Systems Chemical Processing High-Temp O-Rings Hydraulic Equipment Aerospace-Grade Seals
Continuous Service-30°C to +230°C
Short-Term Peak+250°C short-term
Compression SetVery good
ASTM D2000HK
Relative Cost●●●●●
Recommended for
Petrol & diesel Mineral oils Most acids Ozone & UV High heat
Keep away from
Ketones Esters Amines Brake fluid Steam (std. grade)

NBR

Nitrile Butadiene Rubber

The industry standard for oil and fuel contact at moderate temperatures, with excellent abrasion resistance and a wide hardness range. Proven across automotive, hydraulic and general engineering duty. NBR is specified by acrylonitrile (ACN) content: high-nitrile grades (around 45% ACN) give maximum oil and fuel resistance, while low-nitrile grades (around 18 to 20% ACN) trade some oil resistance for better low-temperature flexibility.

Engineer's note

The oil-and-fuel workhorse, and the value pick. It just does not like sunlight or ozone. If the part lives outdoors, go Neoprene or EPDM instead. Indoors around oil, nothing gives you more for the money.

Oil Seals Hydraulic & Pneumatic Automotive Pump & Valve Seals Transformer Gaskets
Continuous Service-40°C to +110°C
Short-Term Peak+120°C short-term
Compression SetGood
ASTM D2000BG
Relative Cost●●○○○
Recommended for
Mineral oils Petrol & diesel Grease Hydraulic fluid Water
Keep away from
Ozone Sunlight Ketones Brake fluid

CR

Neoprene / Chloroprene

Inherently flame retardant, which makes it a frequent pick for electrical and marine duty.

Engineer's note

The all-rounder. Takes weather, moderate oil and a bit of flame without complaint. It rarely wins any single category outright, but when a part sees a little of everything, this is the safe call.

Electrical Gaskets Marine Seals Flame-Retardant Duty General Industrial
Continuous Service-40°C to +110°C
Short-Term Peak+120°C short-term
Compression SetGood
ASTM D2000BC
Relative Cost●●●○○
Recommended for
Weather & ozone Moderate oils Refrigerants Flame (self-extinguishing)
Keep away from
Strong acids Ketones Aromatics

SBR

Styrene Butadiene Rubber

Good impact strength and aging behaviour, ideal where volumes are large and the environment is mild.

Engineer's note

Cheap, tough and great against abrasion, which is exactly why it belongs indoors and dry. No oil, no ozone, no sunlight. For general-purpose pads, bushes and buffers on a budget, it is hard to beat.

Washers Pads & Bumpers General Mouldings Water Service High-Volume Parts
Continuous Service-40°C to +90°C
Short-Term Peak+100°C short-term
Compression SetFair
ASTM D2000AA
Relative Cost●○○○○
Recommended for
Abrasion Impact Water Mild chemicals
Keep away from
Oils Fuels Ozone Sunlight Heat
Have a question?

Choosing a compound

Which rubber is best for high temperature?

Silicone (VMQ) handles −60°C to +225°C and FKM (Viton) up to +230°C. Silicone is better for extreme cold and food/medical contact; FKM is better where fuels, oils and aggressive chemicals are present.

Which rubber is best for outdoor use?

EPDM and Silicone. Both have excellent UV, ozone and weathering resistance. EPDM is the cost-effective choice for outdoor seals; Silicone adds a much wider temperature range.

Which rubber is best for oil and fuel contact?

NBR (Nitrile) is the standard for oils and fuels at moderate temperatures. FKM (Viton) is the upgrade for higher temperatures and more aggressive media.

What hardness should a rubber seal be?

Most static seals work at 50 to 70 Shore A. Low closure-force applications like LED luminaires use soft 30 Shore A silicone; dynamic or abrasive duties often need 80–90 Shore A.

Not sure which polymer?

Tell us the application. We answer with a grade, a price and a lead time.

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