DuPont™ Vespel® SP-1

DuPont™ Vespel® SP-1 is widely used for:

  • Insulators
  • Valve seats
  • Balls
  • Gaskets
  • Poppets
  • Wafer clamping rings
  • In-chamber semi-conductor parts

Performance Characteristics:

  • Operating temps from cryogenic to 500°F (260°C)
  • Ultra-high purity
  • Minimal electrical and thermal conductivity
  • Maximum strength and elongation
  • Low outgassing
  • Improved tech uniformity
  • Excellent wear for longer life

Common Brands:

  • DuPont™ Vespel®

Authorized Distributor of DuPont™ Vespel Polyimide
Download Vespel for Valves White Paper
Military and Aerospace Spline Couplings Machined From DuPont Vespel Parts & Shapes White Paper

DuPont™ Vespel® SP-1

Unfilled, offering superior electrical and thermal insulation properties

DuPont™ Vespel® SP-1 unfilled offers superior wear and insulation properties with operating temperatures from cryogenic to 260°C (500°F). Vespel® SP-1 has low electrical conductivity and the highest elongation and purity of the SP family. Available as stock shapes. For Vespel® SP-1 chemical resistance view our chart.

Semiconductor manufacturers often find components fabricated from Vespel® SP-1 shapes useful in production processes. 

The inherent resistance of DuPont™ Vespel® to stress relaxation allows it to maintain much of its apparent modulus over extended periods of time, resulting in long-term sealing performance.

Want to lean more? Download DuPont™ Vespel® for Valve Seats and Seals white paper.

DuPont™ Vespel® SP-1 is available as isostatically molded billet and unidirectionally pressed slab specified as Type IM and Type IP respectively per ASTM D6456-10 / MIL-R-46198. Vespel® SP-1 is specified as Class 1 per AMS 3644G.


PLAQUE Dimensions:
5 in x 5 in – 10 in x 10 in
0.062 in – 2 in
ROD Outside Diameter:
0.125 in – 6 in
GRADES Unfilled

Length, width, thickness, and diameter tolerances vary by size, by manufacturer, brand, and grade. Vespel® SP-1 is also available in ball and bar shapes.


Typical Properties OF DuPont™ Vespel® SP-1 Polyimide
Units SP-1
Tensile strength
23°C (73°F)
D1708 / D638 MPa (kpsi) 86.2
Tensile strength
260°C (500°F)
D1708 / D638 MPa (kpsi) 41.4
Elongation at break
23°C (73°F)
D1708 / D638 % 7.5
Elongation at break
260°C (500°F)
D1708 / D638 % 6.0
Flexural modulus
23°C (73°F)
D790 MPa (kpsi) 3,100
Flexural modulus
260°C (500°F)
D790 MPa (kpsi) 1,720
Compressive stress at
10% strain, 23°C (73°F)
D695 MPa (kpsi) 133
Deformation under
13.8 MPa (2,000 psi) load
D621 % 0.14
Coefficient of friction at
PV = .875 MPa m/s
(25,000 psi-ft/min)*
Coefficient of friction at 
PV = 3.5 MPa m/s
(25,000 psi-ft/min)*
Static coefficient
of friction in air*
PV limit (unlubricated)**   MPa-m/s
(kpsi ft/min)
Other Properties      
Coefficient of thermal
23–300°C (73–572°F)
E831 µm/m/K
(10-6 in/in-°F)
54 (30)
Hardness D785 Rockwell E 45–60
Water absorption
24 hr at 23°C (73°F)
D570 % 0.24

*Versus carbon steel, steady state, unlubricated, in air, thrust bearing. **PV limits for any material vary with different combinations of pressure and velocity as well as other conditions.

Need more information about this material? Use our interactive plastic properties table

The information set forth herein is furnished free of charge, is based on technical data that DuPont believes to be reliable, and represents typical values that fall within the normal range of properties. This information relates only to the specific material designated and may not be valid for such material used in combination with other materials or in other processes. It is intended for use by persons having technical skill, at their own discretion and risk. This information should not be used to establish specification limits nor used alone as the basis of design. Handling precaution information is given with the understanding that those using it will satisfy themselves that their particular conditions of use present no health or safety hazards and comply with applicable law. Since conditions of product use and disposal are outside our control, we make no warranties, express or implied, and assume no liability in connection with any use of this information. As with any product, evaluation under end-use conditions prior to specification is essential. Nothing herein is to be taken as a license to operate or a recommendation to infringe on patents.

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