CNC Machining PEI (Ultem) Services
Accelerate your project with our advanced CNC milling and turning services for PEI. Optimize your material yield and reduce costs without sacrificing the strict tolerances and optical clarity your application demands.
Your Trusted Contract Manufacturing Partner for ULTEM®
As a premier, ISO-certified contract manufacturer, we specialize in the custom CNC machining of high-performance thermoplastics, with a dedicated focus on ULTEM® (PEI) resins. We don’t just cut plastic—we act as a seamless engineering extension for the world’s leading medical, semiconductor, and aerospace OEMs.
From complex, low-volume prototypes to high-volume contract production runs, we leverage advanced multi-axis CNC technology and strict, industry-compliant quality management systems. Our deep expertise in material behavior, proper thermal management, and stress-relieving annealing ensures that every ULTEM 1000 or 2300 component we deliver meets your exact specifications—on time, every time, and with full structural integrity.
Why Choose ULTEM® (PEI) for Precision Machined Parts?
Polyetherimide (PEI), widely recognized by its trade name ULTEM®, stands out as a premier, high-performance amorphous thermoplastic engineered for the most demanding environments. Where standard plastics fail under heat, pressure, or chemical exposure, ULTEM maintains its exceptional mechanical strength, rigidity, and dimensional stability.
With a continuous-use temperature rating up to 340°F (170°C) and inherent flame retardancy, it has become the material of choice for critical, load-bearing applications across the aerospace, medical, semiconductor, and electronics industries.
Benefits of ULTEM® (PEI)
- Outstanding Heat Resistance:Maintains strength and dimensional stability at elevated temperatures.
- High Strength & Stiffness:Excellent mechanical performance and creep resistance for structural applications.
- Inherent Flame Retardancy:UL94 V-0 rated with low smoke generation.
- Excellent Electrical Properties:High dielectric strength and reliable insulation performance.
- Medical-Grade Compatibility:Withstands repeated sterilization processes, including autoclave, gamma, and EtO.
Machinable ULTEM™ (PEI) Grades
We precision-machine a comprehensive range of genuine SABIC ULTEM™ resins, balanced perfectly for your specific stiffness, heat resistance, and budget requirements:
- ULTEM™ 1000 (Unfilled):Translucent amber, highly ductile, and FDA/USP Class VI compliant. Perfect for reusable medical devices, electrical connectors, and instruments.
- ULTEM™ 2100 / 2200 (10% & 20% GF):Opaque tan. Provides stepped-up rigidity and higher dimensional precision with lower thermal expansion for light structural supports and fixtures.
- ULTEM™ 2300 (30% GF):Opaque tan. The industry standard for high loads. Features extreme tensile strength and absolute stability for aerospace structural parts and insulation blocks.
- ULTEM™ 2400 (40% GF):Opaque tan. Offers maximum modulus and the lowest thermal expansion (CTE) for precision clamping parts and heavy-duty components.
- ULTEM™ 4000 (Wear-Resistant):Opaque black. PTFE & graphite filled for a low coefficient of friction. Built for dry-running environments like sliding bearings and bushings.
- ULTEM™ 5000 (Carbon-Fiber):Opaque black. Superior strength-to-weight ratio and fatigue resistance for high-stress defense and flight-ready aerospace brackets.
- ESD / Anti-Static PEI:Carbon-loaded to control surface resistivity. Designed to protect sensitive electronics in semiconductor test sockets and IC handling tools.
- ULTEM™ CRS5000 & 9085:Specialty industrial formulations offering advanced chemical resistance or strict aircraft interior flame/smoke (FST) compliance.
Machined PEI Properties
Ideal for demanding applications, ULTEM™ (PEI) offers an exceptional combination of durability and precision. Below are the core engineering properties that make it a premier choice for high-performance CNC machining.
| Property Description | Metric Value | Imperial Value / Spec |
| Tensile Strength, Yield | 110 MPa | 16,000 PSI |
| Elongation at Break | 20% – 60% | 20% – 60% |
| Material Hardness | Rockwell R120 | Rockwell M109 |
| Heat Deflection Temp (HDT @ 1.8MPa) | 200°C | 392°F |
| Material Density | 1.27 g/cm³ | 0.0459 lbs/in³ |
| Available Colors | Natural Translucent Amber | Industrial Black / Opaque Tan |
Overcoming Your ULTEM® Machining Challenges
ULTEM® (PEI) is a premier engineering plastic, but its extreme rigidity, heat sensitivity, and high material cost make it notorious for machining failures in inexperienced shops. Here is how we eliminate the typical risks to safeguard your project, budget, and timeline:
ULTEM™ carries high inherent stresses from extrusion, which heavy machining aggressively unleashes. Without expert intervention, parts inevitably warp after unclamping or crack under field stress. We neutralize this hazard by integrating proprietary, multi-stage thermal annealing protocols before, during, and after cutting—locking in absolute geometric stability for the lifespan of the component.
Glass-filled grades (like ULTEM™ 2300) are highly abrasive, dulling standard tooling instantly. Once a cutter loses its edge, the resulting friction creates localized heat zones that melt the plastic, cause stress whitening, and leave ragged burrs. Our solution relies on ultra-sharp, micro-polished diamond (PCD) tooling paired with continuous, high-pressure air blasts to achieve crisp, burr-free edges and pristine surface finishes.
Because raw ULTEM™ stock is exceptionally expensive, inefficient machining layouts or high scrap rates will immediately destroy your project's budget. Our manufacturing engineers utilize advanced CAD/CAM nesting algorithms to squeeze maximum part yield from every slab or bar. This meticulous material optimization, combined with tight in-process inspection, ensures your cost-per-part remains highly competitive.
Components bound for semiconductor vacuum chambers or medical environments cannot tolerate a single micron of contamination from recycled resins, metallic dust, or sulfur-based cutting fluids. We protect your compliance by sourcing exclusively 100% virgin SABIC resins—backed by full MTR and CoC documentation—and processing them inside dedicated, plastic-only CNC cells.
ULTEM® CNC Services & Capabilities
CNC Machining Services
CNC Milling Services
CNC Turning Services
Swiss Machining Services
5-Axis CNC Machining Services
Annealing & Post-Processing
Advanced DFM (Design for Manufacturing) Co-Engineering
We actively optimize your CAD files to compress cycle times and protect your budget against ULTEM’s high raw stock costs. Our engineers conduct a strict plastic-specific DFM review before cutting, modifying wall transitions and internal corner radii to match high-rigidity end mills while eliminating localized stress-concentration risks. By deploying advanced CAM nesting algorithms down to 1 mm spacing footprints, we routinely maximize material utilization and reduce expensive raw material scrap by up to 25% across production runs.
High-Precision Metrology & Semiconductor-Grade Contamination Control
For semiconductor vacuum chambers and medical assemblies, dimensional precision must be backed by absolute material purity. We verify tight tolerances down to ±0.01 mm using climate-controlled, automated CMMs and non-contact optical measuring systems. To eliminate hydrocarbon residues that cause outgassing in vacuum fields, parts undergo multi-stage ultrasonic decontamination in specialized non-ionic baths. Every micro-thread is verified under 40x magnification microscopy for zero-burr compliance before being nitrogen-purged and dual-layer vacuum sealed.
Why Choose Us for ULTEM® Machining?
We operate under strict, internationally recognized quality management systems. Our production lines are fully certified to meet the absolute traceability, risk management, and rigorous documentation standards demanded by the aerospace, defense, and medical device industries.
Cross-contamination can ruin high-purity plastic components. We isolate our engineering plastics from metal machining areas, utilizing dedicated CNC centers, plastic-specific cutting fluids, and non-marring fixturing to ensure zero metallic dust or sulfur contamination.
We never compromise on material integrity. Every batch of ULTEM™ we machine is sourced directly from approved SABIC distributors, accompanied by comprehensive Material Test Reports (MTRs) and Certificates of Conformance (CoCs) to guarantee 100% virgin resin.
From complex single-digit functional prototypes to high-volume production runs of tens of thousands of parts, our flexible manufacturing infrastructure adapts to your timeline. We deliver consistent, scalable precision at a highly competitive cost-per-part.
XTPROTO Manufacturing Facility
Our massive 160,000 square foot climate-controlled manufacturing footprint is engineered to absorb high-capacity, heavy-volume ULTEM® and high-performance polymer contracts. To eliminate the risk of cross-contamination, we host dedicated, plastic-only CNC machining cells isolated from metal dust. This massive infrastructure runs high-speed 5-axis centers and automated Swiss bays under tight temperature controls, preventing the ambient thermal expansion that often ruins high-cost PEI raw stock during large-scale production runs.
AS9100D & ISO 13485 Certified Quality Assurance
We operate under strict ISO 9001, ISO 13485, and AS9100D quality management systems to meet the absolute traceability and compliance required by medical and aerospace OEMs. Inside our fully isolated, climate-controlled metrology labs, our quality team utilizes automated CMMs and non-contact optical systems to routinely verify micro-tolerances down to ±0.01 mm on complex ULTEM® geometries. We guarantee zero stress-whitening, zero micro-cracks, and flawless structural integrity—fully backed by mill-direct SABIC material certifications, MTRs, and comprehensive inspection reports with every single batch.
120+ Engineering & Technical Specialists
With an engineering bench of over 120 specialists, we provide direct technical support throughout the production lifecycle. This team includes dedicated plastic-tooling engineers and CAM programmers who analyze how PEI behaves under dynamic cutting loads. By optimizing precise feed rates to prevent friction-melting and designing custom, non-marring workholding, our engineering team ensures that your technical drawings are executed accurately with minimal material waste.
ULTEM® (PEI) Machining Tips
- Coolant Selection:We use only non-aromatic, water-soluble mixtures or dry high-pressure air blasts. Standard aromatic or halogenated synthetic coolants are prohibited on our floor, as they chemically attack PEI and cause micro-cracks.
- Stress Relief:Every extruded stock block undergoes programmed thermal annealing cycles. This process is carried out before roughing and between critical finishing steps to eliminate internal stresses that cause thin-walled parts to warp.
- Grade-Specific Tooling:We select tools based on the exact material grade. While unfilled ULTEM™ 1000 is processed with micro-grain carbide cutters, glass-reinforced ULTEM™ 2300 is machined exclusively with Polycrystalline Diamond (PCD) tools to counter the abrasive 30% glass fibers and maintain tight dimensions.
Our PEI CNC Machining Parts
Surface Finishing Options for PEI (ULTEM®)
We provide specialized surface treatments to meet the functional and aesthetic requirements of your machined PEI parts:
Technical Specifications
- Machining Tolerances:Down to ±0.05 mm (±0.002″) on standard dimensions; up to ±0.01 mm for micro-features and critical alignment holes.
- Available Material Grades:full series support including ULTEM™ 1000, 2100, 2200, 2300, 2400, 4000, 5000, and ESD-safe formulations
- Maximum Component Dimensions:1200 × 800 × 150 mm
- Surface Roughness:Ra 0.8 – 3.2 μm
- Standard Production Lead Time:According to the contract schedule
Production Workflow
- DFM Review:We analyze your 3D models and blueprints specifically for PEI behavior, verifying wall thicknesses to prevent stress concentration before cutting.
- Raw Material Prep:We source verified stock blocks and perform precision blank cutting, documenting tracking numbers for full batch traceability.
- CNC Machining:Production runs on optimized 3-axis and 5-axis CNC centers using grade-specific cutting tools to prevent friction-melting.
- Quality Inspection:Parts undergo dimensional inspection in our metrology lab, matching finished parts against drawings to deliver full MTRs.
Precision PEI Manufacturing with XTPROTO
To prevent environmental stress cracking (ESC) and warping, XTPROTO enforces strict quality protocols when machining Polyetherimide. We run programmed thermal annealing cycles both before and after cutting to eliminate internal residual stresses and secure dimensional stability. Our workshop eliminates chemical risk by strictly utilizing certified non-aromatic, water-soluble coolants that protect the polymer’s integrity during production.We fully leverage the physical properties of PEI to deliver specialized component features. Our finishing department performs precision vapor and manual polishing to restore optical clarity for amber-colored fluid sight glasses and viewports. Additionally, the material’s natural rigidity allows us to regularly machine complex thin walls and micro-pinhole arrays down to a verified tolerance of ±0.01 mm.
Industry Applications for Machined PEI
Medical
Electronics & Electrical
Automotive & Fluid Handling
Semiconductor Equipment
Laboratory Instruments
Aerospace & Defense
Frequently Asked Questions (FAQ)
What specific quality certifications does XTPROTO hold for high-risk industry components?
How does XTPROTO prevent raw material contamination during the production of semiconductor and medical parts?
ULTEM raw stock is exceptionally expensive. How do you mitigate cost inflation for large production runs?
Which specific tool selection criteria do you use to machine glass-filled grades like ULTEM™ 2300?
What quality deliverables and shipping documentation do you provide with each PEI order?
Secure Precision with XTPROTO
Ready to transition your technical drawings into reliable components? Upload your 3D models and specification blueprints through our secure request system. Our engineering department will perform a comprehensive manufacturing evaluation and deliver a detailed, binding quotation based on your exact volume, material grade, and lead-time requirements. Partner with XTPROTO to eliminate compliance risk and establish stable, repeatable quality across every production run.