URETHANE SPRINGS GUIDE

Item		Urethanes for heavy loads					High-deflection type urethane foams (porous)	Low repulsion urethanes
		H type	M type	S type	L type	Economy type
Hardness (Shore A)		95	90	80	70	90	N / A (foam)	70
Catalog No.		TUS•US•USN	EX•QX•EST ESBT•ESU ESUB•A•E•EL LA•C•AX•CX AZ•AZX•UT UTH•UD•UDH	-	-	AE•LAE•CE AEX•CEX	PA•PLA	AN•LAN•CNN ANX•CNX•AZN AZNX•UTN UDN
Tensile strength (N/cm2) {kgf/cm2}		4511{460}	4462{455}	2941{300}	3138{320}	2452{250}	490{50}	1176{120}
Elongation (%)		450	550	500	650	540	250	250
300% modulus (N/cm2) {kgf/cm2}		1755{179}	1304{133}	931{95}	372{38}	1225{125}	-	-
Repulsion elasticity (%)		23	28	56	51	42	50	6
Tearing strength (N/cm2) {kgf/cm2}		1206{123}	1147{117}	539{55}	451{46}	686{70}	294{30}	343{35}
Specific gravity		1.28		1.27	1.26		1.16	1.02
Permanent strain (%) *		26	24	27	25	27	25	1
Operating environment temperature (°C)		-20~+70					-5~+80	-20~+70
Melting point (°C)		220		200		180	230~250	200
Embrittlement point (°C)		-70			-60	-45	-70	-50
Ignition point (°C)		500					450	400
Features	Weather resistance	Each type has better weather resistance than ordinary rubber materials.
	Water resistance	Can be used even if exposed to a small amount of water. (Cannot be used under conditions of constant water immersion.)
	Oil resistance	Can be used even if exposed to a small amount of cutting oil. (Cannot be used under conditions of constant oil immersion.)
	Discoloration	Becomes discolored when exposed to ultraviolet rays (including sunlight), however there is no adverse effect on performance. Relatively more discoloration occurs with high-deflection type urethane foams than with other types.
Properties		•Provides the largest load resistance, for better contour forming. •Because of the small deflection amount, this type can be used only for simple forming.	This type has physical properties intermediate between the H and S types, and can be used for general purposes.	Although the load resistance is lower, the larger deflection amount allows deeper forming.	Although the hardness is equivalent to general rubber materials, this type has superior abrasion resistance and mechanical strength.	Although the load resistance and durability (permanent strain) are somewhat inferior to the M type, the prices are lower.	•Can be used for high deflection (40%max.) and high load applications. •The lateral expansion is about half that of the M type at an equivalent deflection. •Because this type is foamed urethane, it provides excellent heat radiation performance.	With low permanent strain and excellent shock absorbing performance, this type can deliver antivibration performance.
Applications (reference)		Machining of thin stainless steel plates or steel plates approximately 2mm thick	Machining of thin plates of materials such as aluminum or brass	•Bulging •Shallow drawing	•Drawing •Guerin method •Wheelon method	More suitable for smallvolume production than the M type.	Often used as pad cushions and cam return cushions.	•Vibration proofing •Machining of soft materials such as films.

The above figures are actual measurements at room temperature 23°C, and do not constitute guaranteed specifications.
　 *method of measuring permanent strain (JIS K7312)
　　 1) 24 hours at 70°C with 25% compression
　　 2) Cooled for 30 min. in laboratory at 23°C
　　 3) Strain is measured.

: Excellent : Satisfactory : Slightly poor : Unacceptable

Item	Cost to load ratio	Machinability	High speed endurance	Load stability	Permanent strain	Initial pressure	Operating environment temperatures
Urethane springs
Coil springs
Gas cushions