Vespel Machined Parts
Vespel is DuPont's family of unfilled and filled polyimide shapes — the benchmark material for extreme-temperature, high-vacuum, and radiation-hard machined parts. Rated for continuous service beyond 550°F (288°C) and cryogenic service to −452°F, Vespel holds its dimensions and mechanical properties where every other plastic has long since failed. It is non-outgassing at high vacuum, inherently self-lubricating in filled grades, and resistant to most chemicals and radiation.
Vespel is a premium material with a premium price — it is specified when no other option survives the environment. Federal Materials machines Vespel SP-1, SP-21, SP-22, and SP-3 grades to customer prints, holding the tight tolerances that aerospace, semiconductor, and defense applications demand.
Note: Vespel = polyimide. These terms are used interchangeably in engineering practice; the DuPont trade name Vespel refers to the same base chemistry.
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- Bushings and bearings — dry-run self-lubricating (SP-21/SP-22) for vacuum, cryogenic, and extreme-temperature applications
- Thrust washers and wear pads — low friction, high PV capability
- Seals and back-up rings — reciprocating and rotary, hard vacuum service
- Semiconductor process tooling — ultra-clean, low outgassing, particle-free
- Aerospace structural components — lightweight metal replacement to 550°F
- Valve seats and poppets — chemical and cryogenic service
- Insulators and stand-off spacers — dielectric at elevated temperature
- Custom shapes and prototypes — machined from rod, plate, or near-net compression-molded blanks
Typical Tolerances
| Dimension type | Production tolerance |
|---|---|
| Critical turned dims (OD/ID) | ±0.0005" |
| General machined dims | ±0.002" |
| Hole location (CNC milled) | ±0.002" |
| Surface finish | 32–63 µin Ra standard; 16 µin on request |
Vespel is machinable to very fine tolerances. Parts should be inspected at controlled temperature (68°F/20°C) due to the material's predictable but non-trivial CTE. Lot-specific CTE data is available on request for critical applications.
Grade Selection
| Grade | Filler | Key advantage |
|---|---|---|
| SP-1 | Unfilled | Best dielectric, chemical resistance |
| SP-21 | 15% graphite | Self-lubricating; best for wear surfaces |
| SP-22 | 15% graphite + 10% PTFE | Lowest friction coefficient |
| SP-3 | 15% MoS₂ | Dry-run lubrication; vacuum-compatible |
Specify grade on your RFQ or describe the application and we will recommend.
Finish Options
| Finish | Description |
|---|---|
| As-machined | Clean, deburred — no post-treatment required or recommended |
| Polished bores | Lapped to 16 µin Ra for precision bearing and seal fits |
| No coating | Vespel should not be plated or painted in most applications |
Do not blast, etch, or apply aggressive surface treatments to Vespel — the polyimide matrix is sensitive to alkalis.
Standard Turnaround
| Stage | Lead time |
|---|---|
| Quote response | Same business day |
| Prototype / first article (1–5 pcs) | 3–7 business days |
| Short run (6–25 pcs) | 7–14 business days |
| Production run (25+ pcs) | 14–21 business days |
Vespel is a specialty material with longer raw-stock lead times than commodity plastics. We maintain SP-1 and SP-21 rod and plate in common sizes; other grades confirmed at quoting.
Materials We Stock (Vespel Stock Shapes)
| Form | Grade | Sizes |
|---|---|---|
| Rod | SP-1 | ¼" – 4" diameter |
| Rod | SP-21 | ¼" – 4" diameter |
| Plate | SP-1 | 0.250" – 2.000" thick |
| Near-net blanks | SP-1, SP-21 | Custom; reduces machining time and material waste |
Call for availability on SP-22 and SP-3 grades. Near-net compression-molded blanks are available for high-quantity orders and can significantly reduce cost per part.
Quality & Inspection
- Dimensional inspection — in-process and final to print; CMM first-article
- Material certification — DuPont-traceable C of C for SP grade
- Outgassing qualification — ASTM E595 TML/CVCM data available for aerospace and vacuum applications
- Visual inspection — porosity, surface finish, edge condition
- Clean-room packaging — cleanroom bag and box standard for semiconductor orders
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Request a Quote →More Related Guides
- Torlon Machined Parts — PAI, often a cost-effective Vespel alternative
- PEEK Machined Parts — high-performance thermoplastic
- Teflon Machined Parts — PTFE for chemical resistance and low friction
- Custom Machined Standoffs
- CNC Turning Thermoset Rod