General Design Guide to Elastomeric Materials

 

Elastomer Types

Natural Rubber

SBR

Nitrile

Neoprene

Butyl

EPDM

Chloro-Butyl

Silicone

Fluoro

-Silicone
Trade Names

NR

SBR

NBR,

Buna N

CR

IIR

EPDM

CIIR

PVMQ,

VMQ

FVMQ
Specific Gravity

.93 - 1.1

.94 - 1.1

1.0 - 1.2

1.2 - 1.4

1.1 - 1.3

.86 - 1.1

.92 - 1.1

.95 - 1.2

1.2 - 1.4
Useful Durometer Range (Shore A)

30 - 85

40 - 85

35 - 85

35 - 80

40 - 75

40 - 90

40 - 70

30 - 75

30 - 75
Tensile Strength (psi)

3000 -

4500

900 -

2000

1000 -

3500

2500 -

4000

1300 -

2000

1600 -

2200

900 -

2200

700 -

1200

900 -

1200
Elongation at Break (%)

350 - 800

500

400 - 600

650 - 900

500 - 700

600 - 800

150 - 500

500-1000

200 - 500
Q at Resonance (Transmissibility)

4 - 10

5 - 10

3.5 - 5

4 - 8

3.5 - 5

4 - 8

2 - 4

2.5 - 8

4 - 7
Tan d (G² /G¢ ratio)

.1 - .25

.1 - .2

.2 - .3

.12 - .25

.2 - .3

.12 - .25

.25 - .5

.12 - .4

.14 - .25
Static Shear Modulus (psi)

60 - 400

100 - 400

60 - 350

100 - 220

100 - 360

120 - 350

100 - 400

80 - 350

100 - 220
High Temperature Limit (° F)

Continuous

Intermittent

160

250

160

250

200

300

200

300

225

250

250

325

250

275

350

600

325

500
Low Temperature Limit (° F)

(Approx. 5:1 Stiffening)

-60

-60

-35

-40

-50

-50

-40

-100

-70
Ultimate Shear Stress (psi)

950 - 1300

550 - 850

550 - 1200

550 - 1200

150 - 450
Tear (lbs/in)

200 - 250

150 - 200

200

200 - 250

150 - 200

100 - 250

90 - 360

50 - 150

55 - 240
Compression Set (%)

22 hrs @158° F

22 hrs @300° F

70 hrs @158° F

70 hrs @212° F

70 hrs @325° F

70 hrs @270° F

9 - 20

10 - 15

50

 

18

20

 

 

 

24

20

15 - 20

70

 

10 - 20

15 - 20

35

70

 

10 - 20

10 - 30

75 - 80

100

90 - 95

 

 

 

40 - 80

80 - 100

65 - 70

 

 

3 - 10

10 - 20

22

 

 

20 - 60

3 - 5

8 - 20

18 - 40

 

 

10 - 20

3 - 5

20 - 40
Linear Shrinkage (%)

(325° F Mold Temperature)

2 - 3

1.5 - 2.5

2 - 3

3.5 - 5

2.5 - 3

3.5 - 5

3 - 4

3 - 4
Air Permeability at Room Temp. (cm3/ sec× cm3× atm) 10-7

0.5

0.25

0.13

0.1

0.02

0.8

20

4.2

Ratings: Poor - Fair- Good- Very Good - Excellent

 

Elastomer Types

Natural Rubber

SBR

Nitrile

Neoprene

Butyl

EPDM

Chloro-Butyl

Silicone

Fluoro

-Silicone
Oil Resistance

Poor

Poor

Excellent

Good

Poor

Poor

Fair

Fair

Good
Electrical Resistivity

Excellent

Good

Poor

Very Good

Excellent

Excellent

Excellent

Good

Good
Flame Resistance

Poor

Poor

Poor

Good

Poor

Poor

Poor

Fair

Fair
Impact Resistance

Excellent

Excellent

Good

Good

Fair

Good

Fair

Fair

Fair
Abrasion Resistance

Excellent

Very Good

Good

Excellent

Good

Good

Good

Poor

Poor
Tear Resistance

Excellent

Fair

Fair

Good

Good

Good

Good

Poor

Poor
Weather Resistance

Fair

Fair

Poor

Very Good

Very Good

Very Good

Very Good

Excellent

Excellent
Oxidation Resistance

Good

Good

Good

Excellent

Excellent

Excellent

Excellent

Excellent

Excellent
Ozone Resistance

Poor

Fair

Fair

Excellent

Good

Excellent

Very Good

Excellent

Excellent

Ratings: Poor - Fair- Good- Very Good - Excellent

 

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