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  Urethane Springs

P.P.C'S large inventory of urethane compression springs are designed primarily for applications where corrosion, vibration, and magnetism prevent the use of conventional steel springs. Also, urethane springs have proven to be the safest, most efficient and reliable compression springs for punching, stamping and drawing dies.

 
As compared to conventional springs, the advantages of the urethane springs include the following:
  • High load-carrying capability
  • High dielectric strength and non-magnetic
  • Protection against marring/galling
  • Longer life
  • Abrasion resistance
  • Oil and solvent resistance
  • Low noise
  • Vibration damping and shock absorbence
  • 100% load-bearing surface
  • Bondable to mating parts
  • Effectiveness between - 30º F and 180º F
An example of urethane material's load-carrying capability is shown in the following table which is presented in pounds that cause 1/8 inch deflection:
 
Conventional heavy duty steel die spring
Up to 500 Lbs.
Urethane springs
Up to 2,600 Lbs.
Urethane bar stock
Up to 90,000 Lbs.
Urethane slab stock
Unlimited
 

P.P.C'S urethane spring material is a polyether-elastomer that reacts similarly to an incompressible fluid. The volume of material moved by compression is displaced laterally in the form of bulging sides. An approximation to the change in diameter of one of our standard cylindrical urethane springs can be made by incresing the diameter by the same amount of compression.
Example: A 2.00-inch long spring is to be deflected 15 percent or .30 inches. The diameter will then also increase approximately by .30 inches. This material's lateral expansion must be considered for many applications, especially when they have to fit inside cavities.

The recomended maximum free (unloaded) length is two-and-one-half time's the spring out side diameter, although springs may be stacked with guide rods and washer-shaped spacers, for taller applications.

Suggested maximum cyclic frequencies and deflection percentages of free length are sumarized by the following, for 95A spring.

 
Maximum Deflection
Cycles Per Hour
     
Slow speeds or short runs
less than 25%
200
Intermittent
up to 25%
700
Continuous
up to 15%
12,000
     
P.P.C stocks urethane spring lengths as indicated on the following pages, plus a 24-inch length. We also cut to any desired length (up to 24 inches) although this material may be easily cut to length using a conventional brand saw that has a suggested four-hook carbon blade with a raker set, or may be lathe cut with machine tool bits with a positive rake of from 5 to 10 degrees. For high volumes, we have a CNC machine to accurately cut these to any lengths.
 
P.P.C'S Softer Grades Compression Springs
 
Stock Number
Inside Dia-d
Outside
Dia-D
Duro
Meter
Free Length
Approx
U018-0500-60A
0.17
0.69
60A
0.5
U018-0750-60A
0.17
0.69
60A
0.75
U018-1000-60A
0.17
0.69
60A
1
U018-1250-60A
0.17
0.69
60A
1.25
U018-(length)-60A
Any to 12-1/2
         
           
           
Stock Number
Inside Dia-d
Outside
Dia-D
Duro
Meter
Free Length
Approx
U018-0500-80A
0.17
0.69
80A
0.5
U018-0750-80A
0.17
0.69
80A
0.75
U018-1000-80A
0.17
0.69
80A
1
U018-1250-80A
0.17
0.69
80A
1.25
U018-(length)-80A
Any to 12-1/2
 
 
 
           
           
Stock Number
Inside Dia-d
Outside
Dia-D
Duro
Meter
Free Length
Approx
U018-0500-90A
0.17
0.69
90A
0.5
U018-0750-90A
0.17
0.69
90A
0.75
U018-1000-90A
0.17
0.69
90A
1
U018-1250-90A
0.17
0.69
90A
1.25
U018-(length)-90A
0.17
0.69
90A
Any to 12-1/2
         
         
         
 
Stock Number
Inside Dia-d
Outside
Dia-D
Duro
Meter
Free Length
Approx
U025-0500-60A
0.23
0.75
60A
0.5
U025-0750-60A
0.23
0.75
60A
0.75
U025-1000-60A
0.23
0.75
60A
1
U025-1250-60A
0.23
0.75
60A
1.25
U025-1500-60A
0.23
0.75
60A
1.5
U025-(length)-60A
Any to 12-1/2
 

       
Stock Number
Inside Dia-d
Outside
Dia-D
Duro
Meter
Free Length
Approx
U025-0500-80A
0.23
0.75
80A
0.5
U025-0750-80A
0.23
0.75
80A
0.75
U025-1000-80A
0.23
0.75
80A
1
U025-1250-80A
0.23
0.75
80A
1.25
U025-1500-80A
0.23
0.75
80A
1.5
U025-(length)-80A
Any
to 12-1/2


Stock Number
Inside Dia-d
Outside
Dia-D
Duro
Meter
Free Length
Approx
U025-0500-90A
0.23
0.75
90A
0.5
U025-0750-90A
0.23
0.75
90A
0.75
U025-1000-90A
0.23
0.75
90A
1
U025-1250-90A
0.23
0.75
90A
1.25
U025-1500-90A
0.23
0.75
90A
1.5
U025-(length)-90A
Any to 12-1/2
         
 
Stock Number
Inside Dia-d
Outside
Dia-D
Durometer
Free Lngth
Approx
U031-0500-60A
0.3
0.81
60A
0.5
U031-0750-60A
0.3
0.81
60A
0.75
U031-1000-60A
0.3
0.81
60A
1
U031-1250-60A
0.3
0.81
60A
1.25
U031-1500-60A
0.3
0.81
60A
1.5
U031-(length)-60A
Any to 12-1/2
           
           
Stock Number
Inside Dia-d
Outside
Dia-D
Duro
Meter
Free Length
Approx
U031-0500-80A
0.3
0.81
80A
0.5
U031-0750-80A
0.3
0.81
80A
0.75
U031-1000-80A
0.3
0.81
80A
1
U031-1250-80A
0.3
0.81
80A
1.25
U031-1500-80A
0.3
0.81
80A
1.5
U031-(length)-80A
Any to 12-1/2
         
Stock Number
Inside Dia-d
Outside
Dia-D
Duro
Meter
Free Length
Approx
U031-0500-90A
0.3
0.81
90A
0.5
U031-0750-90A
0.3
0.81
90A
0.75
U031-1000-90A
0.3
0.81
90A
1
U031-1250-90A
0.3
0.81
90A
1.25
U031-1500-90A
0.3
0.81
90A
1.5
U031-(length)-90A
Any to 12-1/2
         
 
Stock Number
Inside Dia-d
Outside
Dia-D
Durometer
Free Lngth
Approx
U037-0500-60A
0.36
0.88
60A
0.5
U037-0750-60A
0.36
0.88
60A
0.75
U037-1000-60A
0.36
0.88
60A
1
U037-1250-60A
0.36
0.88
60A
1.25
U037-1500-60A
0.36
0.88
60A
1.5
U037-(length)-60A
Any to 24
           
Stock Number
Inside Dia-d
Outside
Dia-D
Duro
Meter
Free Length
Approx
U037-0500-80A
0.36
0.88
80A
0.5
U037-0750-80A
0.36
0.88
80A
0.75
U037-1000-80A
0.36
0.88
80A
1
U037-1250-80A
0.36
0.88
80A
1.25
U037-1500-80A
0.36
0.88
80A
1.5
U037-1750-80A
0.36
0.88
80A
1.75
U037-(length)-80A
Any to 24
Stock Number
Inside Dia-d
Outside
Dia-D
Duro
Meter
Free Length
Approx
U037-0500-90A
0.36
0.88
90A
0.5
U037-0750-90A
0.36
0.88
90A
0.75
U037-1000-90A
0.36
0.88
90A
1
U037-1250-90A
0.36
0.88
90A
1.25
U037-1500-90A
0.36
0.88
90A
1.5
U037-1750-90A
0.36
0.88
90A
1.75
U037-(length)-90A
Any to 24
 
Stock Number
Inside Dia-d
Outside
Dia-D
Durometer
Free Lngth
Approx
U050-0500-60A
0.48
1
60A
0.5
U050-0750-60A
0.48
1
60A
0.75
U050-1000-60A
0.48
1
60A
1
U050-1250-60A
0.48
1
60A
1.25
U050-1500-60A
0.48
1
60A
1.5
U050-(length)-60A
Any to 24
           
           
Stock Number
Inside Dia-d
Outside
Dia-D
Duro
Meter
Free Length
Approx
U050-0500-80A
0.48
1
80A
0.5
U050-0750-80A
0.48
1
80A
0.75
U050-1000-80A
0.48
1
80A
1
U050-1250-80A
0.48
1
80A
1.25
U050-1500-80A
0.48
1
80A
1.5
U050-1750-80A
0.48
1
80A
1.75
U050-2000-80A
0.48
1
80A
2
U050-(length)-80A
Any to 24
           
Stock Number
Inside Dia-d
Outside
Dia-D
Duro
Meter
Free Length
Approx
U050-0500-90A
0.48
1
90A
0.5
U050-0750-90A
0.48
1
90A
0.75
U050-1000-90A
0.48
1
90A
1
U050-1250-90A
0.48
1
90A
1.25
U050-1500-90A
0.48
1
90A
1.5
U050-1750-90A
0.48
1
90A
1.75
U050-2000-90A
0.48
1
90A
2
U050-(length)-90A
Any to 24
 
Stock Number
Inside Dia-d
Outside
Dia-D
Durometer
Free Lngth
Approx
U062-0500-60A
0.6
1.13
60A
0.5
U062-0750-60A
0.6
1.13
60A
0.75
U062-1000-60A
0.6
1.13
60A
1
U062-1250-60A
0.6
1.13
60A
1.25
U062-1500-60A
0.6
1.13
60A
1.5
U062-(length)-60A
Any to 24
         
Stock Number
Inside Dia-d
Outside
Dia-D
Duro
Meter
Free Length
Approx
U062-0500-80A
0.6
1.13
80A
0.5
U062-0750-80A
0.6
1.13
80A
0.75
U062-1000-80A
0.6
1.13
80A
1
U062-1250-80A
0.6
1.13
80A
1.25
U062-1500-80A
0.6
1.13
80A
1.5
U062-1750-80A
0.6
1.13
80A
1.75
U062-2000-80A
0.6
1.13
80A
2
U062-(length)-80A
Any to 24
           
Stock Number
Inside Dia-d
Outside
Dia-D
Duro
Meter
Free Length
Approx
U062-0500-90A
0.6
1.13
90A
0.5
U062-0750-90A
0.6
1.13
90A
0.75
U062-1000-90A
0.6