How to Read ASTM D2000 Specifications

Doug Sharpe

President of Elasto Proxy

ASTMASTM D2000 is a published specification that provides buyers and suppliers with a standard way to describe rubber. Designed for automotive applications, this classification system is also used by other industries because it’s clear, concise, and highly descriptive.

As I explained in my last blog entry, buyers will benefit by understanding ASTM D 2000 because this specification provides a “common language” for communicating with sealing suppliers. So let’s begin a lesson in the language of rubber and learn how to speak ASTM D 2000.

Call Outs

ASTM D 2000 uses letters and numbers to describe or “call out” the properties of vulcanized rubber. Type and Class are the most important call outs to consider.  In the language of rubber, think of Types and Classes as nouns and verbs – the building blocks of sentences. There are also other callouts that, like adjectives and verbs, help with descriptions.

Here’s a complete “sentence” in ASTM D2000. We’ll use it as an example throughout.

ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

Yes, this dialect in the language of rubber looks complicated. But let’s crack the code one step at a time by examining its components:

  • Standards
  • Year Last Revised
  • Units of Measure
  • Grade
  • Durometer Hardness and Tensile Strength
  • Suffixes

Standard

The first few letters and numbers (ASTM D 2000) simply indicate the standard.

ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

Year Last Revised

The -3 after the 2000 indicates the year (2003) in which the standard was last revised.

ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

Units of Measure

The M after the -3 indicates that all units of measure are metric. So, when you’re reading about temperatures, think Centigrade instead of Fahrenheit. If the M is missing, then English units are used.

ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

Grade

In our example, the 2 after the -3 is the grade of the rubber. Typically, grade numbers are only given when the basic requirement (Grade 1) doesn’t sufficiently describe the material’s properties.

ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

Type

Type describes a rubber’s temperature resistance – and is so important in our sample ASTM D 2000 “sentence” that Type is like a noun! Look for the type (B) after the grade (2).

 ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

With types, a rubber material must meet the following requirements after 70 hours of heat aging at a specified temperature.

  • Change in tensile strength: ±30%
  • Change in hardness:  -50% max.
  • Change in hardness ±15 points

So what are these specified temperatures? That’s what the table below explains.

Table 1 – Types

ASTM D 2000 assigns a letter to each test temperature. Again, our example uses Type B.

Type Test Temp (°C)
A 70
B 100
C 125
D 150
E 175
F 200
G 225
H 250
J 275
K 300

Class

Class describes a rubber’s resistance to swelling in oil after 70 hours at the temperatures listed in Table 1, but only up to 150° C. In case you’re wondering, that’s the maximum temperature stability of the test oil (IRM No. 903) used in ASTM D 2000.

In the language of rubber, class is so important that it’s like a verb. By putting a noun (type) and verb (class) together, we form a basic sentence in ASTM D 2000. As with most English sentences, too, our verb (G) follows the noun (B).

ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

Table 2 – Classes

ASTM D 2000 then assigns lettered classes to each maximum allowable volume swell by percentage (%). Again, our example uses Class G.

Type Max. Swell (%)
A No requirement
B 140
C 120
D 100
E 80
F 60
G 40
H 30
J 20
K 10

 

Durometer Hardness and Tensile Strength

ASTM D 2000 defines durometer hardness and tensile strength with a three-digit number.

ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

In our example of 714, the 7 denotes a material with a durometer hardness of 70 ± 5 A. The 14 indicates that the tensile strength must be at least 14 MPa, or 2032 psi.

Suffixes

As we’ve learned, the language of rubber contains the equivalent of nouns, verbs, adjectives, adverbs, and other parts of speech. There are suffixes, too – literally. These combinations of letters and numbers can be quite long, depending on your requirements. As you can see, our example is half suffix!

ASTM D 2000-3 M2BG714B14EA14EF11EF31 EO14 EO34 F17

Table 3 – Suffix Letters

ASTM D 2000 assigns a letter to each suffix elements.

Suffix Required Test
A Heat Resistance
B Compression Set
C Ozone or Weather Resistance
D Compression-Deflection Resistance
EA Water Resistance
EF Fuel Resistance
EO Oil and Lubricant Resistance
F Low Temperature Resistance
G Tear Resistance
H Flex Resistance
J Abrasion Resistance
K Adhesion
M Flammability Resistance
N Impact Resistance
P Staining Resistance
R Resilience
Z Other (User-Defined)

Language can be colorful, of course, and the language of rubber is no exception. Remember, however, to always assume that the color of rubber is black except for FC, FE, FK, and GE. If you need a different color rubber material, then consider that a color change may also change the material’s physical properties. When in doubt, check with your supplier!

Table 4 – Suffix Numbers

In addition to letters, suffixes contain numbers.

  • The first number specifies the duration of the test and the test method.
  • The second number indicates the testing temperature.

Understanding all of the suffix numbers in ASTM D 2000 is a tall order and means purchasing the specification. If you do buy the entire standard from ASTM International, then refer to Tables 4 and 5 for details. Remember, too, that there are restrictions on how much of ASTM D 2000 you can share.

Class Dismissed!

I hope you’ve enjoyed this lesson in the language of rubber and now understand how to read ASTM D 2000 specifications. If you have questions, need clarifications, or are still wondering if a rubber material is right for your application, please contact Elasto Proxy. How can we help you?

Best Practices for Specifying Rubber Materials

Rubber Profiles Elasto Proxy

Doug Sharpe
President of Elasto Proxy

Why is it important to ask for more than just a “neoprene or EPDM 60 duro seal” when ordering sealing products? If you don’t specify physical properties or consider ASTM standards, a supplier may deliver a seal that has the the wrong characteristics. All materials aren’t the same, and many different types of rubber compounds are available. So where can you find the expert advice you need to select the right rubber material?

Watch Elasto Proxy on YouTube

Elasto Proxy’s new YouTube video, Best Practices for Specifying Rubber Materials, provides answers to important questions about material selection. If you don’t know where to start, or even which questions to ask, then this instructional video is for you. “Best Practices for Specifying Rubber Materials” can also help if you’ve ordered rubber materials before, but want to be sure you’re asking all the right questions.

At just 2:39 minutes long, this new YouTube video is co-hosted by Megan Beaulieu, Elasto Proxy’s Executive Assistant, and me. “Best Practices for Specifying Rubber Materials” is the first of several instructional videos that Elasto Proxy will feature on our YouTube channel, so Megan and I start with the basics.

After describing some problems caused by ordering just a “neoprene or EPDM seal,” we outline the ASTM classification system and discuss how rubber compounds vary in terms of hardness and flexibility. If you need a neoprene or EPDM seal, then you need to know about the ASTM D2000 and ASTM D1056 standards.

Rubber Seals and ASTM Standards

ASTM International is an organization that provides standard ways to describe or call-out rubber materials based on physical properties. ASTM designations are based primarily on Type (heat resistance) and Class (oil resistance), but include additional values that describe a compound’s other characteristics.

ASTM D2000 describes the properties of vulcanized rubber materials such as natural and reclaimed rubber. Although this ASTM standard is entitled “Standard Classification System for Rubber Products in Automotive Applications,” other industries can and do use it for non-automotive applications.

ASTM D1056 covers flexible cellular rubber products known as sponge rubber and expanded rubber. As ASTM International’s “Standard Specification for Cellular Materials,” it defines cellular rubber by Type, Class, and Grade.

How Can We Help You?

Watching “Best Practices for Specifying Rubber Materials” is a great way to get started, but we appreciate that you may have questions of your own, too. By listening to all of your requirements and understanding all of our needs, Elasto Proxy can recommend the right sealing solution for your specific application. To learn how our solutions providers can help, contact us today.

Seal Selection and Thermal Expansion

Thermal Expansion
Thermal Expansion

Doug Sharpe
President of Elasto Proxy

In my last blog entry, I recommended grabbing a cup of coffee before diving into this week’s discussion about the coefficient of thermal expansion. Yes, the caffeine will help if you prefer explanations over calculations. But our topic this week is less about math and more about the physical properties of elastomers. Let me explain.

To choose the right compound for your sealing application, you need to know how that material will perform at specific temperatures. Physical properties such as modulus of elasticity are important, too, but let’s stick to temperature while you’ve got last week’s blog entry in mind and a hot cup of coffee in hand.

Elastomers and Changes in Temperature

All elastomers have a coefficient of thermal expansion. Simply put, this value describes how the material changes in length, area, or volume with changes in temperature. In the case of rubber door and window seals, linear expansion is important because it helps to predict how a change in temperature will literally lengthen or shorten the seal.

Let’s consider two examples, both involving a rubber door seal and a metal door frame. At high temperatures, the rubber seal expands more than the metal frame. At low temperatures, the seal contracts more than the surrounding metal material. So what happens if you choose the wrong rubber? The door may not shut if it’s hot, or may admit wind and weather if it’s cold.

Now think back to last week’s blog entry, in which we learned about tractor trailers that make northbound runs from Miami to Montreal. For drivers and vehicles alike, the temperature changes can be extreme – especially during winter. If a rubber door seal is made of a compound that can’t handle these changes, the seal may fail and jeopardize the load.

Temperature Range and Temperature Change

Seal performance isn’t just about temperature range then. To select the right compound, you must also consider temperature change – how the rubber reacts when the temperature rises and falls.

Take a look at the chart below. The data required some conversions – and some may quibble with the math – but our takeaway here is simpler than the calculations. As you can see by looking at the right-hand column, all rubber is not the same when it comes to temperature changes!

Thermal Expansion

Material Thermal Stability X10-6mm/°C
EPDM 150° C 160
NBR 120° C 230
SBR Ambient 220
Silicone Ambient 2.5
Urethane 100° – 150° 180
Neoprene 130 – 150
Teflon 230 50 – 80

Table 1: Some Common Elastomers and Their Coefficients of Thermal Expansion

For more information, including the coefficient of thermal expansion calculation itself, please visit the National Physical Laboratory. Another good on-line technical resource is Rubber as an Engineering Material: Guidelines for Users.

Feeling Stressed Out?

Don’t spill your coffee, but the relationship between elongation and temperature isn’t always so straightforward. For starters, elastomer elongation increases over a specific temperature range and then decreases at still higher temperatures.

Then there’s something called the Joule effect, which occurs only when an elastomer is under tensile stress. The easiest way to explain this is to imagine a rubber band suspending your coffee cup. If you warm the elongated rubber band with an infrared lamp (your desk lamp, perhaps), the rubber band doesn’t expand. In fact, it retracts to support the load.

Choose a Partner – Not Just a Provider

Experimenting with rubber bands and coffee cups makes for a fun science project (and perhaps a coffee-stained desk), but our job at Elasto Proxy is to help you choose the right sealing solution for your specific application. By analyzing all of your application requirements and listening to all of your needs, we can offer answers to your sealing questions – and not just explanations of coefficients and calculations.

For over 25 years, Elasto Proxy has provided sealing solutions to partners in a variety of industries. How can we help you? Please comment below, or contact us at our website today.

Seal Selection and Service Temperatures

Service Temperatures
Service Temperatures

Doug Sharpe
President of Elasto Proxy

Did you have a cup of coffee this morning? How about a glass of orange juice. If you enjoyed either of these beverages, thank a trucker. Each day, the commercial trucking industry moves billions of dollars’ worth of commodities between the United States, Canada, and Mexico. For long-haul truckers who drive from places like Miami, Florida to Montreal, Canada, the trip lasts days and involves extreme changes in temperature – especially during the winter months.

For driver and vehicle alike, temperature changes can be challenging. Tractor trailers contain plenty of rubber and plastic parts – not just the tires. If a door or window seal is made of a compound that can’t handle hot or cold temperatures, the seal may fail.  Farmers, road crews, and construction workers face this problem, too, even though their vehicles travel much shorter distances. Outdoor temperatures can rise and fall rapidly, so makers of mobile specialty vehicles also need dependable sealing solutions.

Service Temperature of Elastomers

Rubber softens at high temperatures and becomes hard as a hockey puck at low temperatures. Many different elastomers are available, so how do you choose the right rubber for your sealing application?

With outdoor products such as door and window seals, you need to consider the service temperature for starters. This chart from our website lists temperature range for various types of rubber.

Material Compound Minimum Temperature Maximum Temperature
SBR -85° F +158° F
Natural Rubber -85° F +158° F
EPDM -80° F +300° F
Neoprene -65° F +225° F
Nitrile -55° F +275° F
Urethane -70° F +250° F
Silicone -180° F +525° F
Viton -40° F +500° F

Service temperature isn’t the only factor to consider, of course, but let’s start with the basics.

Rubber Seals at Low and High Temperatures

At low temperatures, elastomers do more than harden. They become less flexible. If they reach their brittle point, they may even crack. That’s what happened to the rubber O-rings on the Space Shuttle Challenger in a 1986 tragedy that claimed the lives of seven astronauts. NASA officials believed the seals were suitable for cold weather, but the O-rings were unable to withstand sub-freezing temperatures.

The weather at Cape Canaveral, Florida was unusual on that day, more like Montreal than Miami. But high temperatures can also cause seals to fail.  When the temperature of an elastomer approaches its upper service limit, the rubber may undergo chemical changes that are irreversible.

With each 10° C (18 °F) increase in temperature, the rate of some chemical reactions doubles. Again, consider the case of a trucker who is northbound bound from Miami to Montreal in the middle of a (typical) winter. If extreme cold will reduce the life of a door seal that’s helping to protect a valuable shipment, isn’t the cost of a compound with a wider temperature range a sound investment?

Elastomer Performance and Predictability

Even if a seal doesn’t fail, elastomer performance becomes less predictable when rubber reaches the limits of its service temperature range. So does that mean that we can predict how a compound will expand, contract, and recover with changes in temperature? Yes, but this is why there’s more than just temperature range alone to consider. Each material handles these changes differently.

In my next blog entry, I’ll discuss a concept called the coefficient of linear thermal expansion. So drink your orange juice – and grab a cup of coffee – before trucking over next week. In the meantime, do you have any questions about seal selection and service temperature? Please let me know by commenting below, or connect with me on LinkedIn.

Hockey Isn’t Just for the Hard-Headed

Hockey and Rubber
Hockey and Rubber

Clyde Sharpe
President of International Sales, Elasto Proxy

Yes, I was wrong. But I should have been right! In my last blog entry, I predicted that there wouldn’t be an NHL season this year.  Last December, the negotiations between owners and players were as hard as a hockey puck on a cold winter’s day. Then a January thaw occurred. A deal was struck and teams took to the indoor ice for training camp. A week later and without any preseason games, the league launched a strike-shortened 48-game regular season. That’s 34 games less than in normal years and there won’t be any inter-conference play until the Stanley Cup Finals.

Here at Elasto Proxy headquarters in Quebec, Canada, I’m surrounded by fans of the Habs – the Montreal Canadiens. So unless the Habs host my favorite team, the Calgary Flames, in the Finals, I won’t have a chance to watch Alex Tanguay and company at the nearby Bell Centre. Yet John Rye, Elasto Proxy’s resident Toronto Maple Leafs fan, will have a chance to face-off against Megan Beaulieu and much of our production team when the Canadiens host the Leafs on February 9th. Still, it’s not the lack of inter-conference play that bothers me – and why my NHL prediction should have been right.

Hazards of a Shortened Hockey Season

As the hockey analyst Pierre McGuire explains, players need about 10 games to get into the rhythm of the season. If McGuire is correct (and I think that he is), that’s nearly 20% of this strike-shortened year. The abbreviated season also favors teams whose lineups haven’t changed much since the Los Angeles Kings hoisted the Cup last June. If chemistry counts, then teams like Philadelphia, Montreal, Toronto, the New York Rangers, and even Calgary will need to incorporate new players quickly. Gone is the pace of a full-length season, too, when many good teams slump in the middle yet finish strong in the end.

This year, hockey teams that get off to a slow start are at a disadvantage – and NHL players could be at risk, too. Although many skaters kept themselves in good condition, the strike did not prepare them for a regular season where every game counts and contests have a playoff-like intensity. Some hockey gear is made with shock-absorbing materials and gels that help reduce the risk of injury, but is this protective equipment really up to the task? Concussions aren’t just a problem in hockey, of course, as football fans in the U.S. will tell you.

Hockey Equipment and Player Protection

Except for the ones worn by goalies, most hockey headgear isn’t as eye-catching as the football helmets worn in the NFL (or even the CFL). In terms of preventing head injuries, however, what matters most is what’s inside. Most hockey helmets are made of a lightweight plastic, typically a polycarbonate material, and feature a one-piece or two-piece design. Underneath this hard plastic shell is a liner to help absorb impact and, in some products, a second liner for comfort. Because of our water jet cutting capabilities, Elasto Proxy has experience with custom-fabricating the EVA foam that’s used in helmet inserts.

Hockey protective equipment also includes rubber and plastic components such as mouth guards, ear protectors, and pads.  Mouth guards come pre-formed and then mold to the mouth during use, or can be softened by heating and then molded by biting down on them. Ear protectors, another type of safety equipment, can be inserted into player helmets for extra comfort and protection. The hard plastic elbow pads that some skaters like provide protection, but can cause serious injury to opponents.

What Do You Think?

The NHL is back and the 2013 season is in full-swing. There have been some good games, a few fights, and at least one charging penalty that’s resulted in a one-game suspension. But should the NHL have had a season at all? And how well will hockey equipment help to protect players during the short, intense season?

Hard as a Hockey Puck, Soft as NHL Ticket Sales

Hockey Puck
Hockey Puck

Clyde Sharpe
President of International Sales

Hockey and rubber have similar languages.  In ice hockey, checking is a defense technique for gaining possession of the puck or disrupting your opponent’s play. With rubber components, checking refers to short, shallow surface cracks caused by damaging action.  If you’ve ever watched a hard-fought hockey game, especially during the NHL playoffs, you’ll appreciate the similarities between these two types of “damaging action”. But even if you’re not a hockey fan, you’ve probably heard about the NHL Lockout. Sadly, there may not be a quest for the Stanley Cup this season.

Here at Elasto Proxy’s headquarters in Boisbriand, Quebec, Canada, we’re still enjoying our national winter sport. Sure, there’s less chatter about who’s better – John Rye’s Toronto Maple Leafs, my Calgary Flames, or the Montreal Canadiens that Megan Beaulieu and so many members of our production team love. But there are still CHL games to watch and ice hockey leagues in which plenty of people (myself included) participate. During the winter, I skate in two leagues and use my stature to screen goalies, make assists, and score on tip-ins. During the summer, I play in one ice hockey league and one ball hockey league. It’s great exercise, and nice to see your name on a scoreboard at any time of year.

The NHL enjoys competition, too, but the owners and players are locked in a game of high-stakes poker that could cost them more than ticket sales. Unlike soccer, where all you need is a ball, hockey requires expensive equipment like sticks, skates, pads, and helmets. So as the NHL players and owners raise the stakes and stop the season, the biggest loss may be future players. Without role models like Wayne Gretzky and Maurice Richard, kids may choose other sports – and less expensive ones at that. The NHL is less brutal than it used to be, but the NHL Lockout of 2012 could cause the sport pain for years to come.

As hockey players know, getting hit by a fast-moving puck doesn’t tickle. As Elasto Proxy explains in its Seal Selection Guide, solid rubber profiles are the hardest and most resistant to compression. But some softer elastomers are used in ice hockey, too. Visit a skating rink sometime and look for the rubber profiles between the glass in the boards. Part of their job is to provide vibration resistance. Rubber parts are used in hockey helmets, too. With our water jet cutting capabilities, Elasto Proxy has even custom-fabricated an EVA foam for helmet inserts.

So will there be an NHL season this year? I don’t think so. At this point, the negotiations are as hard as a hockey puck on a cold winter day. Sure, some give-and-take could help end the lockout, but I’ve worked at Elasto Proxy long enough to know that a solid profile doesn’t just turn into a sponge profile. Still, as long as I can play hockey, I know I’ll be all right.

Sanitary Seals for Food Equipment and Medical Equipment

Sanitary Seals | Food Equipment
Sanitary Seals | Food Equipment

Elasto Proxy supplies sanitary seals to the food equipment industry as well as to medical equipment manufacturers and the makers of medical assist devices. Our solutions providers understand your regulatory environment and how some plastic and rubber materials must meet requirements from organizations such as the U.S. Food and Drug Administration (FDA) and the National Sanitary Foundation (NSF). As your supply chain partner, we also understand that when health and safety are at stake, there’s more to business than the bottom line.

Food Safe Seals

For over 20 years, Elasto Proxy has designed, manufactured, and installed replacement seals for vats and tanks at food and beverage processing facilities. By listening to all of your requirements and analyzing all of your needs, our solutions providers can recommend material compounds that meet your pressure, temperature, and sanitary requirements. Food equipment suppliers also trust Elasto Proxy to design and fabricate high-quality rubber components that help keep kitchen employees safe. So whether you need rubber gaskets for refrigerators, high-temperature door seals for restaurant ovens, or protective edges for sharp stainless steel surfaces, you can count on us to provide the right sealing solution.

Medical Seals

Medical equipment manufacturers and the makers of medical assist devices also operate in a highly regulated environment where health and safety are on the line. As a trusted supplier to manufacturers of durable medical equipment, Elasto Proxy designs and custom-fabricates plastic and rubber parts such as medical tubing, diaphragms, and gaskets. Our capabilities also include components such as rubber seals for handicap accessible walk-in bathtubs and foam grips for bed grab handles. With the knowledge and expertise to meet the needs of doctor’s offices, hospitals, and home-health care settings, Elasto Proxy serves suppliers of dental equipment, too.

Specialty Seals

Earning your trust involves more than mastering food-contact requirements or the latest specifications for medical materials. To meet all of your business needs, Elasto Proxy can also supply sanitary seals that match your product’s colors. For example, if you need a rubber gasket to match the color of a medical assist device, we can source the compound from an extruder who uses pantone color matching. Our solutions providers can also design rubber seals that complement color schemes for kitchen equipment such as refrigerators, ovens, and mixers. By listing to all of your requirements and analyzing all of your needs, Elasto Proxy seals-in safety for food and medical equipment.