Comparison of RMA and DIN Standard -SUNGDA GROUP

All conveyor belts follow several internationally accepted rubber covering grade systems, most countries follow the German DIN22102 grade standard, of course, there are also regional grade standards, for example, most American countries are used to follow the American RMA grade standard, then what is the difference between these two standards?

RMA is the abbreviation of “Rubber Manufacturers Association”in United States, it has established two standard grades of rubber conveyor belt cover: RMA-I and RMA-II, the RMA-I (17Mpa) grade meets the higher requirements of rubber stretch and elongation, and usually shows higher cutting and scratch resistance than the RMA-II (14Mpa).

ARPM (Association for Rubber Products Manufacturers), a successor of RMA. Published their conveyor belt handbook in 2011, determining grade 1 with tensile strength of 17 MPa, elongation at break of 400 % and volume loss of 125 mm³, and grade 1 with tensile strength of 14 MPa, elongation at break of 400 % and volume loss of 175 mm³, This means that the standards established by ARPM have higher requirements for abrasion rate.

The DIN standard was established by the “German Institute for Standardization”, the letter “DIN” stands for “Deutsches Institut für Normung”, they formulate specifications and standards as a service to the German industry. They are a highly respected non-profit organization, it has been based in Berlin since 1917, many DIN standards have been converted to EN or even ISO standards. In Europe and many parts of the world, DIN standards are more generally recognized and accepted, especially in the case of abrasion resistant conveyor belt.

The main difference between the two standards is reflected in three technical parameters for rubber cover, namely, the Tensile Strength, the Elongation at Break and the Abrasion Loss.

Item	RMA-I	RMA-II	DIN-W	DIN-Z	DIN-Y	DIN-X
Abrasion Loss (mm³)	max. 150	max. 200	max. 90	max. 250	max. 150	max. 120
Tensile strength (Mpa)	min. 17	min. 14	min. 18	min. 15	min. 20	min. 25
Elongation at break (%)	min. 400	min. 400	min. 400	min. 350	min. 400	min. 450

The following table is currently the main internationally popular conveyor belt implementation standards:

Cover Grade	Country	Applicable Standards	Min.Tensile Strength(Mpa)	Min.Elongation at Break(%)	Max.Abrasion Loss(mm³)
DIN-Z	Germany	DIN22102	15	350	250
DIN-Y	Germany	DIN22102	20	400	150
DIN-X	Germany	DIN22102	25	450	120
DIN-W	Germany	DIN22102	18	400	90
RMA-I	U.S.A	RMA	17	400	150
RMA-II	U.S.A	RMA	14	400	200
ARPM RMA-I	U.S.A	ARPM	17	400	125
ARPM RMA-II	U.S.A	ARPM	14	400	175
ISO-L	International	ISO -10247	15	350	200
ISO-H	International	ISO -10247	24	450	120
ISO-D	International	ISO -10247	18	400	100
AS-N	Australian	AS -1332	17	400	200
AS-M	Australian	AS -1332	24	450	125
AS-A	Australian	AS -1332	17	400	70
SANS-N	South Africa	SANS-1173	17	400	150
SANS-M	South Africa	SANS-1173	25	450	120
SANS-A	South Africa	SANS-1173	18	400	70
BS-M	UK	BS-490	24	450	120
BS-N	UK	BS-490	17	400	200
IS-N-17	India	IS 1891	17	400	200
IS-M-24	India	IS 1891	24	450	150
JIS-G	Japan	JIS-K 6332	14	400	250
JIS-L	Japan	JIS-K 6332	15	350	200
JIS-D	Japan	JIS-K 6332	18	400	100
JIS-H	Japan	JIS-K 6332	24	450	120
GB-H	China	GB/T 7984	24	450	120
GB-D	China	GB/T 7984	18	400	100
GB-L	China	GB/T 7984	15	350	200