3M 695 Riveters Tape is a black polyester film tape with a pressure-sensitive acrylic adhesive, supplied in slit roll formats that include 12.7 mm, 25.4 mm, and 50.8 mm widths. Nominal roll length for the 25.4 mm width is 65.8 m. Total tape thickness is 0.051 mm when measured in accordance with ASTM D3652/D3652M. The product is used in airframe assembly cells to hold rows of rivets and hi-lok fasteners in pre-drilled or reamed holes before squeezer or rivet-gun installation. It is a temporary retention aid; it is not a structural adhesive, permanent bonding film, or sealant.

Manufacturer-published typical values for 3M 695 include tensile strength at break of 438 N/100 mm and elongation at break of 90% using ASTM D3759/D3759M. Adhesion to stainless steel is reported as 33 N/100 mm at 180° peel using ASTM D3330/D3330M. The published service temperature range is −40 °C to 149 °C. These values are nominal product data, not release limits; end users verify peel adhesion on representative aluminum alloys and primers before release for riveting.

Incoming lot control commonly uses peel adhesion to a standard stainless steel panel as a surrogate for substrate-specific adhesion. If the measured value falls below an internally established lower control limit, the roll is quarantined. If the value is above an upper control limit, the roll is restricted to short-dwell operations because higher adhesion may indicate an increased residue risk. These control limits are generated from production history and are not provided in the manufacturer’s standard technical data sheet.

What Limits Adhesion Build on Primed Aluminum in Rivet Holding?

Adhesion build on primed substrates controls the removal window. On bare 2024-T3 aluminum, the acrylic adhesive wets adequately at application temperatures between 15 °C and 38 °C; below 10 °C, wet-out decreases and the tape may not conform fully around countersunk fastener heads. The polyester backing, with elongation at break near 90%, resists the cyclic shear generated by pneumatic rivet hammers operating at production frequencies of 2,000–3,000 impacts/min. If backing yield were excessive, fastener position could shift during driving and cause hole-wall deformation or skin marring. Tapes based on plasticized PVC backing, which typically show elongation above 150%, exhibit greater necking under cyclic shear and are rejected for this reason.

On epoxy or chromated primer surfaces, peel adhesion can rise with dwell because the adhesive flows into primer porosity. A tape left for 72 h at 23 °C may show higher peel values than the same tape left for 24 h. Production shops therefore define a maximum dwell before riveting, commonly 24–48 h for air-conditioned cells. If the assembly is exposed to shop temperatures of 40–60 °C, the dwell should be shortened; published data for this specific configuration is limited, so qualification testing on representative panels is required.

The adhesive is a crosslinked acrylic pressure-sensitive system with a glass transition temperature below −20 °C, allowing wet-out at room temperature. Dynamic shear storage modulus at 1 Hz and 25 °C is typical of general-purpose acrylic pressure-sensitive adhesives and falls in the range of 0.1–1.0 MPa. This viscoelastic balance supplies cohesive strength for clean removal while retaining tack to bare metal. Extended exposure above 100 °C shifts the adhesive toward a more elastic state, which can increase peel force after heat aging.

Surface preparation in production cells begins with solvent wiping using isopropyl alcohol or aqueous alkaline cleaning to remove mill oils and conversion-coating residues. The tape is burnished with polyethylene squeegees at pressures of 0.2–0.4 MPa to improve adhesive contact over rivet heads. Rolls are conditioned at 23 ± 2 °C and 50 ± 5% RH for 24 h before use following ASTM D4332. The acrylic adhesive does not require heat activation and reaches functional holding strength within 20 min at room temperature. Storage above 70% RH may introduce moisture at the adhesive-backing interface and should be avoided. Original polyethylene bag storage at 21 °C ± 3 °C is recommended; published shelf life is typically 18–24 months from the date of manufacture. Shelf life is a storage condition and does not override the need for substrate-specific removal testing after aging.

Contact with low-surface-energy plastics such as polyethylene, polypropylene, or untreated PTFE yields low peel adhesion and is not a valid use case. The acrylic adhesive can be softened by toluene, methyl ethyl ketone, and acetone; prolonged wiping of the exposed tape edge with these solvents can cause adhesive ooze or residue transfer. The tape should be removed before vapor degreasing or hot alkaline cleaning. If silicone contamination is suspected on the substrate, surface verification per ASTM D2578 or water-break-free testing is performed before tape application.

A common production control is to measure unwind force from manual dispensers at 300 mm/min; values between 0.5 N and 2.0 N per 25.4 mm width are typical for this polyester backing. High unwind values above 3.0 N can distort narrow slit rolls during hand application. On automated tape laying heads, splice-free wound rolls reduce variation at tooling corners; these process values are equipment-specific and should be qualified on the actual dispenser.

Acrylic Adhesive Residue, Sulfur-Free Compatibility, and Clean Removal

Unlike rubber-based pressure-sensitive adhesives that can employ sulfur-containing cure systems, the acrylic adhesive of 3M 695 reduces the potential for sulfur staining on aluminum. It also does not introduce silicone contamination, which is relevant when subsequent painting or sealant bonding is specified. Clean removal is a required production characteristic. After dwell of 24 h at 23 °C, removal from bare 2024-T3 aluminum typically leaves no visible adhesive transfer. At temperatures above 100 °C, dwell should be minimized because acrylic adhesives can crosslink and increase the peel force required for removal.

Exposure to phosphate-ester hydraulic fluids or ester-based paint strippers can soften the adhesive and backing. The tape is not intended as a maskant for acid etchants, alkaline cleaners, or anodizing baths. For chemical milling or anodizing processes, 3M 695 does not replace vinyl or lead foil maskants with appropriate chemical resistance. In airframe lines, removal occurs before Alodine or chromic acid anodizing steps, not after.

Aerospace topcoat and sealant processes commonly impose silicone restrictions because silicone transfer can create fisheye defects and interfere with bond primer wetting. In shops where polyimide silicone-adhesive tapes are used in other operations, 3M 695 is isolated in non-silicone-controlled tooling to prevent cross-contamination; the product itself is non-silicone. This is a primary selection reason for rivet holding in assemblies that later enter paint hangars.

Reported production failure modes include adhesive transfer to rivet heads after high-humidity storage, z-direction splitting of the polyester backing if slitting introduces edge nicks, and telescoped rolls after sustained exposure above 40 °C. Edge nicks can propagate during peel removal and leave filament-shaped tape fragments in the assembly. Rolls with visible edge damage are removed from the line and subjected to tensile break testing of narrow strips per ASTM D3759/D3759M.

When Polyester Backing Replaces Vinyl or Polyimide in Fastener Retention

When 3M 695 is compared with general-purpose vinyl tape, the polyester backing provides a thinner total profile, 0.051 mm versus approximately 0.13 mm for a typical vinyl tape such as 3M 471. The lower elongation of 3M 695, near 90%, reduces fastener movement during squeezing, whereas vinyl tape may stretch more and shift the fasteners under load. The 149 °C service temperature limit of 3M 695 is higher than the typical 80 °C continuous rating of general-purpose vinyl tape. The acrylic adhesive also provides higher room-temperature adhesion to bare aluminum than many vinyl tape adhesives formulated for marking or low-cost protective uses.

When polyimide tape is considered, the comparison differs. Polyimide tape with silicone adhesive, such as 3M 5413, is rated for continuous service up to 260 °C and is selected for autoclave or paint-bake cycles above 149 °C. However, polyimide tape is more expensive per linear meter, and silicone adhesive transfer is a known cause of fisheye defects in paint systems. 3M 695 uses an acrylic adhesive rather than silicone, so it is selected when rivet retention occurs at ambient to moderately elevated temperatures and the assembly later enters a bond primer or topcoat process with zero silicone tolerance. Polyester tape cannot substitute for polyimide in high-temperature cure cycles; the backing of 3M 695 may degrade above the published 149 °C limit.

Crepe paper masking tape has lower tensile strength and absorbs moisture, which can cause drying and loss of adhesion in humid shops. 3M 695 uses polyester film that does not absorb water and maintains dimensions under humidity changes. However, polyester backing is more expensive than crepe paper, so the product is reserved for fastener retention and other applications where backing stretch and moisture pickup would create rework.

In production validation, first-article inspection on a representative skin assembly typically includes fastener height above skin after taping, absence of tape-induced shim, and peel-removal residue on bare 2024-T3 and 7075-T6 aluminum. Incoming lot adhesion is checked per ASTM D3330/D3330M; if measured below the lower control limit established from historical capability data, the lot is quarantined. Upper-side adhesion deviations may indicate an increased residue risk after long dwell, so the lot is restricted to short-dwell operations. Published data for this specific configuration is limited; therefore, process limits are generated from each production facility’s standard panel preparation and dwell profile.