Pre-coating for micro-screws

frein filet pour micro vis

Our dry thread locking solutions for the
watchmaking - eyewear - jewelry industries

Watches, glasses, handbags, jewelry… all these objects are subjected to vibrations and shocks which “naturally” lead to the loosening of micro-screw assemblies.

To replace the traditional application of liquid threadlocker, in the 80s we developed pre-coating processes adapted to micro-screws from Ø0.7 to M2. The technique was then extended to axles and other threaded parts.

Today, our expertise is recognized by the world’s leading luxury brands. Every year, we process millions of parts for leading watchmakers, eyewear manufacturers, leather goods manufacturers and jewelers.

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Our HLOCK locking solutions

We offer 2 types of braking solutions for watchmaking, eyewear and jewelry applications:

  • Locking with micro-encapsulated adhesive: The technique consists in pre-coating the threads with a two-component Epoxy micro-encapsulated adhesive that activates only during assembly. During screwing, the adhesive released by the crushing of the microcapsules polymerizes and bonds the threaded elements together.
    This is the most effective and least expensive anti-unscrewing solution.

  • Repositionable locking with polyamide resin: During screwing, the polyamide deposited on the thread is compressed. The radial tension created by the elastic deformation of the product causes the locking. The locking function can be repositioned, as the polyamide deformation is reversible, making it possible to screw and unscrew several times.
    The locking function is active immediately after screwing.
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HLOCK range specifications

The HLOCK range comprises 3 theadlocking products:

ProductsHLOCK 2510-V2HLOCK 2353-V2 HLOCK POLYAMIDE
FonctionLocking by bonding Locking by bondingRepositionable locking 
TypeMicroencapsulated adhesiveMicroencapsulated adhesivePolyamide resin
ColorOrangeBlueGreen
Standard coating length4 to 6 threads4 to 6 threads4 to 6 threads
Curing time at 20°3 days3 daysImmediate effect
Number of uses1 to 2 uses in certain cases1 to 2 uses in certain cases3 to 5 uses
Locking torque on screwing (Cfv)LowLowMedium
Release torque (Cdes)HighHighMedium
Vibration resistanceExcellentExcellentGood
Resistance to impactExcellentExcellentGood
Chemical resistanceGoodGoodGood
Sealing assuredYesYesYes
PFASNoNoNo
Storage temperature -10°C to 35°C10°C to 35°C10°C to 35°C
Shelf life2  years2  years2  years

Applications & deposit technique

  • Together with our customers, we have developed a wide range of applications: back screws, decorative screws, bracelet screws and pins, folding clasp screws, extension link screws, headless screws, winding rods, movement screws, cage screws, crown screws, hinge screws…

  • We use a variety of processes to handle all types of screws, including headless shafts. Our equipment is suitable for parts from Ø0.7 to M2.

  • Coating length and thickness are determined for each application according to assembly parameters: number of engaged threads, assembly clearance, thread quality, part material, etc.

  • For technical validation of our solution, we supply sample batches for testing by the customer. We can also carry out torque measurements on customer assemblies.

Special services and packaging

  • All parts are inspected on entry: we carry out a batch count and a visual check.

  • The parts are treated and dried to ensure that the patch is dry to the touch. They are then vacuum-packed.

  • For fragile parts or parts with special surfaces, we carry out individual treatments. The parts received in the tray are treated one by one with forceps, and individually checked by the operator.

  • We also offer bagging in small, economical batches.
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Comparison of different locking solutions in the Luxury goods

 HLOCK 2510-V2 HLOCK 2353-V2HLOCK Polyamide Thin, heat-crosslinked elastomer Liquid adhesives 
Simple assembly⭐⭐⭐⭐⭐ 
Vibration and shock resistance⭐⭐⭐⭐ ⭐⭐ ⭐ ⭐⭐⭐⭐
Multiple uses⭐ ⭐⭐⭐⭐ 
Process reliability ⭐⭐⭐ ⭐⭐⭐ ⭐⭐⭐
Cleanliness ⭐⭐⭐⭐
Capability ⭐⭐⭐ ⭐⭐⭐⭐ ⭐⭐⭐
Capacity⭐⭐⭐ ⭐⭐⭐ 
Aesthetically preserved parts ⭐⭐⭐ ⭐⭐⭐ ⭐ ⭐⭐
Price⭐⭐⭐⭐ ⭐⭐⭐⭐ ⭐⭐

Discover our HLOCK range documentation

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