PEI Rod for CNC Machining & Mechanical Parts | JUTAI

CNC Machining Considerations for PEI Rods

1. Material Selection

Natural PEI is suitable for components requiring electrical insulation, dimensional stability and balanced mechanical properties. Glass filled PEI may be considered when higher stiffness is required.

2. Internal Stress and Annealing

PEI rods may contain residual stress from manufacturing. For tight-tolerance components, controlled annealing and appropriate machining procedures can help reduce dimensional changes.

3. CNC Turning and Milling

PEI rods can be machined into bushings, rollers, sleeves, spacers and other cylindrical components. Cutting parameters and tool selection should be optimized to reduce heat generation and surface damage.

4. Dimensional Inspection

Critical dimensions can be inspected according to customer drawings, with inspection reports available when specified in the order.

5. Custom Finished Components

JUTAI offers machining from raw PEI rods to finished components, helping customers reduce material preparation and subcontracting steps.

Natural PEI or PEI GF30?

Choose Natural JTYPEI® NA When You Need:

• Better machinability
• Balanced strength and toughness
• Electrical insulation
• Natural translucent amber appearance
• A smoother machined surface
• Complex CNC-machined features
• Better resistance to impact than reinforced PEI
• Lower tool wear during machining

Choose JTYPEI® GF30 When You Need:

• Higher stiffness
• Lower thermal expansion
• Increased structural strength
• Better dimensional stability under load
• Improved resistance to deformation
• Greater stability during thermal cycling

JTYPEI® GF30 contains 30% glass-fiber reinforcement and can be produced using SABIC ULTEM™ 2300 resin where required.

Glass fibers make the material more abrasive to machining tools and may produce a less uniform machined surface than natural PEI.

Design Considerations for PEI Components

Avoid Sharp Internal Corners

Use suitable internal radii where possible. Sharp corners and sudden changes in wall thickness can create stress concentration and increase the risk of cracking.

Maintain Consistent Wall Thickness

Large differences in wall thickness may create uneven stress and dimensional movement during machining or operation.

Allow for Thermal Expansion

The component design and assembly clearance should account for temperature changes and the coefficient of thermal expansion of PEI.

Evaluate Fastening Stress

Avoid excessive interference fits, over-tightened metal fasteners and concentrated assembly loads.

Use appropriate clearances, washers or inserts where necessary.

Confirm Chemical Compatibility

PEI provides resistance to many oils, fuels, alcohols and weak aqueous solutions. However, it may be affected by strong alkalis, chlorinated solvents and certain polar solvents.

Chemical compatibility must be evaluated under the actual temperature, concentration, pressure, mechanical stress and exposure time.

Machining Recommendations

Turning and Milling

Use sharp carbide or tungsten-carbide tools suitable for aluminum and engineering plastics.

Apply stable clamping without excessive force. Excessive clamping pressure can deform the rod and affect the final dimensions.

Drilling

For large holes, begin with a smaller pilot hole and gradually enlarge the diameter.

Avoid excessive feed rates, heat accumulation and direct drilling with oversized tools.

Cooling

Use adequate cooling to prevent excessive cutting heat, material burning, tool adhesion and dimensional instability.

Water-soluble cutting fluids may be used where appropriate, subject to final cleaning and application requirements.

Annealing

Annealing should be considered for:

• Tight-tolerance components
• Parts requiring extensive material removal
• Thin-wall components
• Parts with large differences in wall thickness
• Components used at elevated temperatures
• Components requiring multiple machining stages

For high-precision components, rough machining followed by intermediate annealing and final machining may improve dimensional stability.

When PEI May Not Be the Best Choice

PEI may not be the first choice when the application involves:

• Continuous temperatures substantially above approximately 170°C
• Strong alkalis
• Chlorinated solvents
• Demanding high-pressure sliding conditions
• Severe dry-running wear
• Repeated high-temperature steam sterilization
• Extreme chemical exposure
• Applications requiring implant-grade certification

Depending on the operating conditions, PEEK, PPSU, PPS or a wear-modified engineering plastic may be more suitable.

Material Supply and CNC Machining

JUTAI supplies natural JTYPEI® NA PEI rod and reinforced JTYPEI® GF30 rod for mechanical engineering applications.

Available services include:

• Material selection
• Standard PEI rod supply
• Cut-to-length service
• Controlled annealing
• CNC turning
• CNC milling
• Drilling and grinding
• Dimensional inspection
• Component assembly
• Worldwide delivery

For complete material properties, available diameters and standard lengths, please refer to the JTYPEI® NA ULTEM™ 1000 PEI Rod product page.

JTYPEI® PEI Rod Application Selection Guide

Frequently Asked Questions

What mechanical components can be made from PEI rod?

PEI rod can be machined into bushings, sleeves, rollers, spacers, guides, insulating supports, positioning parts, equipment fixtures and lightweight structural components.

Is natural PEI suitable for bearings?

Natural PEI may be suitable for selected low-load or intermittent-motion components. It should not automatically be selected for high-speed, heavily loaded or dry-running bearings without a detailed wear evaluation.

When should PEI GF30 be selected?

PEI GF30 should be considered when the component requires higher stiffness, lower thermal expansion and better resistance to deformation under load.

What is the long-term service temperature of natural PEI?

Natural PEI can provide long-term service at temperatures up to approximately 170°C, depending on mechanical load, chemical exposure, pressure and component design.

Can PEI replace metal?

PEI can replace metal in selected components where lower weight, corrosion resistance, electrical insulation and design flexibility are required. Load, temperature and dimensional requirements must be evaluated before replacement.

Can JUTAI machine finished mechanical components?

Yes. JUTAI provides CNC turning, milling, drilling, grinding, annealing and dimensional inspection according to customer drawings or samples.

Where can I find the complete PEI technical data and sizes?

The complete technical data sheet, diameter range and rod specifications are available on the JTYPEI® NA ULTEM™ 1000 PEI Rod core product page.

Request a Material Recommendation

Please provide:

• Component drawing
• Required dimensions and tolerances
• Operating temperature
• Mechanical load
• Sliding speed, if applicable
• Chemical medium
• Electrical insulation requirements
• Required quantity
• Destination country

JUTAI will evaluate whether natural PEI, PEI GF30, PEEK or another engineering plastic is more suitable for the application.