Benefits
Excellent Conformability
The lead foil construction is pliable and can be shaped around irregular contours and detailed geometries, making 3M™ Lead Foil Tape 420 suitable for demanding masking and shielding configurations.
Electrical and Thermal Conductivity
3M™ 420 is formulated to provide both electrical and thermal conductivity. When the lead foil is properly burnished against a metal substrate, metal-to-metal contact can help maintain electrical continuity across the assembly.
Chemical Resistance for Process Masking
The tape is resistant to many chemicals associated with electroplating and anodizing processes and has strong acid/base resistance according to 3M product information. This makes it suitable for selected chemical masking and surface-treatment applications.
Radiation Barrier Applications
Lead foil provides a dense metallic barrier that can be used in selected radiation shielding and masking applications. 3M specifically lists radiation barrier and X-ray plate masking among application ideas.
Custom Die-Cutting
The easy-release liner enables the tape to be die-cut into specific shapes for assembly and manufacturing processes, including detailed or intricate patterns.
Technical Specifications
| Property | 3M™ Lead Foil Tape 420 |
|---|---|
| Product type | Lead foil tape |
| Backing material | Lead foil |
| Adhesive type | Rubber |
| Color | Dark silver |
| Adhesive color | Green |
| Backing thickness | 0.13 mm / 5 mil |
| Total tape thickness | 0.17 mm / 6.8 mil |
| Liner thickness | Approx. 0.09 mm / 3.5 mil |
| Adhesion to steel | 49 N/100 mm |
| Tensile strength | 350 N/100 mm |
| Elongation at break | 12% |
| Temperature use range | -51°C to 107°C |
| Standard roll length | 33 m / 36 yd |
| Electrical conductivity | Yes |
| Thermal conductivity | Yes |
| Water vapor transmission | 1.55 g/m²/24 h |
| Liner | Clear, easy-release film |
Applications
Electroplating Masking
3M™ 420 can be used as a masking material during electroplating. The tape’s conductivity and conformability can be useful where the masking edge needs to maintain close contact with the metal substrate.
Radiation Barrier
The lead foil construction can be used in selected radiation-barrier applications, including X-ray-related masking. The required shielding performance must be evaluated according to the radiation type, energy and system design.
Chemical Milling
The tape can serve as a process masking material during selected chemical milling operations. Chemical concentration, exposure time and temperature should be validated for the specific process.
Moisture Barrier
3M lists moisture barrier as an application idea for 3M™ 420.
Anodizing and Surface Treatment
Its resistance to many chemicals used in electroplating and anodizing makes the tape suitable for selected surface-treatment masking applications.
Paint-Stripping Masking
3M’s technical information lists maskant during paint stripping as an application idea.
Weight Balancing
The dense lead foil construction can provide localized weight for balancing selected equipment components. 3M gives examples such as golf clubs and tennis rackets.
Compatible Materials
3M™ Lead Foil Tape 420 is designed to bond to a variety of surfaces, including most metals. Potential substrates include:
- Stainless steel
- Aluminum
- Steel
- Copper and other metal surfaces
- Selected plastics
- Other industrial substrates compatible with the rubber adhesive
Surface cleanliness and condition can significantly affect adhesion. 3M recommends application to a clean, dry surface above 0°C for best results.
Industries
3M™ Lead Foil Tape 420 may be relevant to:
- Electroplating
- Metal Finishing
- Anodizing
- Chemical Milling
- Aerospace Manufacturing
- Electronics and Electrical Equipment
- Radiation Shielding
- Industrial Equipment
- Sports Equipment
- Specialty Manufacturing
The actual application should be assessed according to the process chemistry, radiation environment, temperature and regulatory requirements.
Why Choose 3M™ Lead Foil Tape 420?
3M™ 420 combines a pliable lead foil backing, rubber adhesive, electrical conductivity and thermal conductivity in a tape construction that can be formed or die-cut into complex shapes. It is particularly relevant where conventional foil tapes may not provide the desired density, conductivity or radiation-barrier characteristics.
Key characteristics include:
- Highly conformable lead foil
- Electrical and thermal conductivity
- Resistance to radiation
- Resistance to moisture and weathering
- Resistance to many process chemicals
- Suitable for selected electroplating and chemical-milling applications
- Custom die-cut capability
- Easy-release liner
For industrial converting projects, Yousan can evaluate appropriate slitting, laminating and precision die-cutting requirements based on the tape construction and finished-part specifications.
Installation Guide
1. Prepare the Surface
Apply the tape to a clean, dry surface. Remove dust, oil, grease and other contamination before application. 3M recommends applying the tape above 32°F / 0°C for best results.
2. Position the Tape
Place the tape over the required masking, shielding or conductive area.
3. Apply Firm Pressure
Press the tape firmly and uniformly onto the substrate to establish good adhesive contact.
4. Feather the Edges
For electroplating applications where edge contact is particularly important, 3M recommends feathering the edges by rubbing the tape down with a smooth-edged plastic tool or similar object. This helps the lead foil conform closely to the metal base.
5. Burnish When Electrical Continuity Is Required
Where appropriate, the lead foil can be burnished to create direct metal-to-metal contact with the substrate, helping maintain the electrical path across the interface.
6. Validate the Process
For electroplating, chemical milling, radiation shielding or other critical applications, validate the complete tape-and-substrate system under actual production conditions.
Storage
Store 3M™ Lead Foil Tape 420 in its original carton under normal conditions of:
- 16–27°C (60–80°F)
- 40–60% relative humidity
Protect the tape from unsuitable environmental exposure and keep it in the original packaging until use. 3M’s technical data recommends using the product within 18 months from the date of manufacture for best performance.
FAQ
What is 3M™ Lead Foil Tape 420?
3M™ 420 is a lead foil tape with a rubber adhesive, designed for electrical and thermal conductivity, masking, moisture-barrier and selected radiation-barrier applications.
Is 3M™ 420 electrically conductive?
Yes. 3M describes 420 as an electrically and thermally conductive lead foil tape.
Is 3M™ 420 thermally conductive?
Yes. Thermal conductivity is one of the product’s stated characteristics.
Is 3M™ 420 a radiation shielding tape?
3M identifies radiation barrier and X-ray plate masking as application ideas. Actual shielding performance must be determined according to the radiation source and application design.
Can 3M™ 420 be used for electroplating?
Yes. Electroplating masking is one of the product’s stated application areas.
Can 3M™ 420 be used for chemical milling?
Yes. 3M lists chemical milling as an application idea. The specific chemicals, concentration, temperature and exposure time should be tested before production.
How thick is 3M™ Lead Foil Tape 420?
The total tape thickness is approximately 0.17 mm (6.8 mil), with a lead foil backing thickness of approximately 0.13 mm (5 mil).
What is the temperature range of 3M™ 420?
The published technical data lists a temperature use range of approximately -51°C to 107°C (-60°F to 225°F).
Can 3M™ 420 be die-cut?
Yes. 3M specifically states that the liner allows the tape to be die-cut into specific shapes for assembly and manufacturing processes.
Can 3M™ 420 be used on metal?
Yes. 3M states that the rubber-based adhesive bonds well to a variety of surfaces, including most metals.
Is 3M™ 420 suitable for outdoor applications?
3M describes the tape as suitable for indoor and outdoor application conditions and notes resistance to moisture, weather and UV degradation.
Does 3M™ 420 contain lead?
Yes. The backing is lead foil. Because lead is a regulated hazardous substance in many jurisdictions, handling, disposal and applicable occupational/environmental requirements should be followed. 3M specifically notes that separately disposed material may be classified as hazardous waste under U.S. RCRA and recommends following applicable regulations.
Downloads
Available upon request:
- 3M™ Lead Foil Tape 420 Technical Data Sheet (TDS)
- Safety Data Sheet (SDS)
- Adhesive Tape Selection Guide
- Product Brochure
- Die-Cutting Capability Guide
Please contact our sales team if you require the latest technical documentation.
