Somewhere between a low-viscosity UV adhesive that flows freely and a filled paste that fights every needle it’s forced through sits a wide middle band — and most standard-range gauges aren’t built for it. The Incure Sniper SN-20 is the first gauge specifically optimized for that band.

Where the Low-Viscosity Range Stops Working

The SN-18 and SN-19 excel at low-viscosity materials, but push a medium-viscosity UV adhesive, a light one-part epoxy, or a thickened cyanoacrylate through either one and the bond pad over-fills — the wider bore simply can’t hold bead control on a thicker material the way it does on a thin one. At 0.681 mm inner diameter, the SN-20 is the first gauge in the Sniper range built for the 1,000–10,000 cP band specifically, delivering the controlled flow that wider gauges lose once viscosity climbs into medium territory.

That 1,000–10,000 cP window is wide enough to cover a meaningful share of one-part epoxies and thickened cyanoacrylates without further gauge changes, which is why the SN-20 tends to be the first gauge evaluated whenever a process moves from a low-viscosity to a medium-viscosity adhesive rather than jumping straight to a narrower option.

That distinction matters because the failure mode on the wrong side of this boundary looks different depending on direction: too wide a bore on a medium-viscosity material over-fills the pad and loses clean thread break-off after retract; too narrow a bore creates unnecessary backpressure and slows the cycle for no placement benefit. The SN-20 sits at the entry point of the medium-viscosity band specifically so it doesn’t over-correct in either direction.

Consistent Break-Off Is the Real Deliverable

Beyond bead width, medium-viscosity dispensing lives or dies on clean break-off — whether the material forms a consistent thread that snaps cleanly after the needle retracts, or strings and leaves a trailing tail that contaminates the next deposit. The SN-20’s bore is sized to deliver consistent volume per stroke and clean break-off at the dispense pressures medium-viscosity adhesives and epoxy formulations actually require, rather than forcing a compromise between the SN-18/19’s flow characteristics and the finer gauges’ backpressure.

A trailing tail that contaminates the next deposit is a subtler defect than an obviously oversized bead, since it can pass a quick visual check on the current part while still leaving stray adhesive on the next one down the line — which is why break-off quality deserves as much attention during gauge qualification as bead width itself.

Email Us if a medium-viscosity adhesive is currently over-filling bond pads on a low-viscosity-range gauge, or stringing on a gauge that’s too fine.

Non-Ferrous Construction and Fit

Like the rest of the standard Sniper range, the SN-20 is machined from phosphor bronze — non-magnetic, non-ferrous, and chemically inert to UV adhesives, epoxies, cyanoacrylates, and common electronics-assembly solvents, eliminating any need for a magnetic particle sweep near sensitive assemblies. The green PP Luer Lock hub color-codes this specific bore size for fast identification during line changeovers.

Specifications and Application Fit

The SN-20 has a 0.879 mm outer diameter, an 18 mm nominal overall length, and ships in packs of 10. The full coating lineup is available: No Coating, Electroless Nickel, Nickel PTFE, Nickel Polymer Type SLK, and Parylene Type C. Recommended materials are medium-viscosity UV adhesives in the 1,000–10,000 cP range, light one-part epoxies, thickened cyanoacrylates, and filled UV formulations, across electronics assembly, optical bonding, and semiconductor packaging.

Positioning in the Sniper Range

For low-viscosity materials under 1,000 cP, the SN-18 (1.039 mm) and SN-19 (0.859 mm) are the better fit, offering higher flow at lower pressure than the medium-viscosity band requires. For tighter placement within the same medium-viscosity band, the SN-21 at 0.610 mm narrows the bead further without leaving the 1,000–10,000 cP range. For high-viscosity gels and filled formulations above 10,000 cP, the SN-23 (0.564 mm), SN-25 (0.437 mm), SN-27 (0.335 mm), and SN-30 (0.234 mm) cover progressively thicker material.

All Sniper gauges in the standard phosphor bronze line share the same PP Luer Lock hub and are available in No Coating, Electroless Nickel, or Nickel PTFE at minimum, keeping dispensing hardware consistent across a gauge change.

Qualifying a process on the SN-20 usually starts with a break-off test rather than a bead-width measurement alone: dispense a series of deposits at production pressure and speed, then inspect for stringing or a trailing tail after each retract. Clean, repeatable break-off across the series confirms the gauge and pressure combination is dialed in; visible stringing on a majority of deposits suggests either the viscosity is higher than the SN-20’s target band or the dispense pressure needs adjustment before moving to a narrower gauge.

See Incure’s full Sniper precision dispensing needle range for the complete gauge comparison. The SN-20 is a strong match for mid-viscosity grades in Incure’s Uni-Weld Multi-Substrates Bonder line, and for Optik UV optical adhesives formulations in the medium-viscosity band. Contact Our Team to confirm gauge selection for a specific medium-viscosity dispensing process.

Visit www.incurelab.com for more information.