What is ASTM D1056?

ASTM D1056 is a standard specification that covers flexible cellular rubber products such as sponge rubber and expanded rubber. These products can be made from synthetic, natural, or reclaimed rubber, possibly with additional polymers, chemicals, or additives. The cellular rubber is categorized based on type, class, grade, (example 2C2) and suffixes, with various grades needing to meet specified physical property requirements.

ASTM D1056 - Type, Class, and Grade

The ASTM D1056 classification is broken down into three sections: type, class, and grade. Additionally, a suffix can be added at the end of the ASTM D1056 classification to signify additional characteristics of the material. However, at Pres-On we do not include a suffix. For example, Pres-On’s NE4100 Neoprene foam is classified as 2C1.

Type

The first classification for ASTM D1056 is type. There are two types possible. Type 1 denotes that the material is a open cell and type 2 signifies that the material is a closed cell.

Type	Cell Structure
1	Open Cell
2	Closed Cell

Class

Class is the second character in the ASTM D1056 classification. It is designated by the letters A,B,C, and D. The letters A-C indicate the oil resistance of the material. Class D represents temperature resistance.

Class	Requirements
A	Non-oil Resistance (EPDM)
B	Oil Resistance with Low Swell (Nitrile)
C	Oil Resistnace with Medium Swell (Neoprene)
D	Extreme Temperature Resistance (Silicone)

Grade

The last character in the ASTM D1056 classification is the grade. There are five grades, and they are numbered 1-5. The grade specifies the amount of force needed to produce 25% compression deflection of the material. A grade of 1 requires the least amount of force and 5 requires the most force.

Grades	Characteristics
1	2-5 psi Compression Deflection
2	5-9 psi Compression Deflection
3	9-13 psi Compression Deflection
4	13-17 psi Compression Defecltion
5	17-25 psi Compression Defecltion

*25% Compression Deflection

Suffix

The suffix of the ASTM D1056 classification refers to additional characteristics the materials may exhibit. A letter from A-W as well as the letter Z are used to signal to the additional features. At Pres-On we do not include the suffix on our material listing. Additional information of every one of our products can be found on their respective product page.

Suffix	Characteristics	Suffix	Characteristics
A	Heat Resistance	L	Water Absorbtion
B	Compression Set	M	Flammability Resistance
C	Ozone Resistance	N	Impact Resistance
D	Compression Deflection Resistance	P	Staining Resistance
E	Fluid Resistance	R	Resilience
F	Low Temperature Resistance	T	Tensile and Elongation
G	Tear Resistance	W	Density
J	Abrsion Resistance	Z	Any Special Requirements
K	Adhesion Resistance

Pres-On's ASTM D1056 Materials and Classifications

Pres-On offers a variety of materials that are classified under ASTM D1056. This includes materials such as neoprene, EPDM, nitrile, sponge rubber, silicone, Viton®, and blended materials. Below you can find all of the materials Pres-On has available and their ASTM D1056 classification.

Series	Material	Classification	Series	Material	Classification
NE4100	100% Neoprene	2C1	P8100UL	Neoprene - EPDM Blend	2C2
NE4300	100% Neoprene	2C3	P8100	Neoprene - EPDM Blend	2C2
NE4400	Neoprene	2C4	P8200	Neorpene - EPDM Blend	2C1
P9100	EPDM	2A2	P8300	Neoprene - EPDM Blend	2C3
P9200	EPDM	2A1	P8400	Neoprene - Vinyl Blend	2C1 / 2C2
P9300	EPDM	2A1	S600	Silicone	2D3
P8600	Nitrile	2B1	Viton®	Fluroelastomer	2B2
P8000	Sponge Rubber	1A2

Series	Material	Classification
NE4100	100% Neoprene	2C1
NE4300	100% Neoprene	2C3
NE4400	Neoprene	2C4
P9100	EPDM	2A2
P9200	EPDM	2A1
P9300	EPDM	2A1
P8600	Nitrile	2B1
P8000	Sponge Rubber	1A2
P8100UL	Neoprene - EPDM Blend	2C2
P8100	Neoprene - EPDM Blend	2C2
P8200	Neorpene - EPDM Blend	2C1
P8300	Neoprene - EPDM Blend	2C3
P8400	Neoprene - Vinyl Blend	2C1 / 2C2
S600	Silicone	2D3
Viton®	Fluroelastomer	2B2

*Click the Series to View Product Page