Dri-Loc 201 Yellow.
High-strength, dry-to-touch pre-applied yellow thread locker for plated and bright-stock fasteners. Inert in storage, cures on assembly, seals while it locks. Specified where Dri-Loc 200’s phosphate-and-oil formulation isn’t the right match — ring gear bolts, electroplated hardware, and clean-finish OEM fasteners.
Standard lead time 1–2 weeks — from receipt at our dock to coated parts back on yours. Rush accommodated on request. Customer pays inbound and outbound freight; F.O.B. St. Charles, IL.
STRENGTH
HIGH
VIBRATION-RATED
TEMP RANGE
400°F MAX
CONTINUOUS SERVICE
CURE
ROOM TEMP
ON ASSEMBLY
SUBSTRATE
PLATED
+ BRIGHT STOCK
REUSABLE
NO
SINGLE-INSTALL
The yellow threadlocker built for cleaner finishes.
Dri-Loc 201 is the plated-fastener member of the Loctite Dri-Loc Thread locker family — the answer for assemblies where the fastener finish isn’t phosphate-and-oil, but the strength requirement is just as demanding.
The 201 formulation is a water-based film engineered to bond on plated and bright-stock substrates — zinc-plated, electroplated, and polished surfaces where the 200 Yellow’s phosphate-and-oil optimization doesn’t apply. Stored on the shelf, the film is dry to touch and dimensionally stable; it does not migrate, does not pick up dust, and does not activate prematurely.
On assembly, mechanical compression between mating threads excludes air from the film and triggers cure. The resulting joint resists loosening from cyclic loading, thermal cycling, and high-frequency vibration. It is not designed to be serviced. Removal is possible with extended torque or applied heat, but the film is consumed in the process; reinstall calls for reapplication.
The yellow pigment is intentional — it gives the line a clear visual inspection cue. A QA tech can verify presence of coating across an entire batch with a glance, which is part of why 201 Yellow shows up on ring gear bolt prints and other high-cycle drivetrain fasteners where plating is the specified finish.
SPEC AT A GLANCE
Why engineers reach for 201 Yellow
Three reasons it shows up on plated-fastener prints — works where 200 can’t, same high-strength target, same yellow visual cue for QA.
- FAMILYDri-Loc 201
- CHEMISTRYWater-based film
- STRENGTHHigh · Vibration-rated
- VISUALYellow · Inspectable
- TEMPUp to 400°F
- SUBSTRATEPlated & bright stock
- SERVICESingle-install
The numbers, plainly.
These are the values engineers most often need before specifying. If anything is missing, ask the engineering desk.
PRODUCT FAMILY
Loctite Dri-Loc 201YELLOW
High-strength member of the Dri-Loc dry-film family for plated and bright-stock fasteners. Distinguishable on inspection by yellow pigment.
CHEMISTRY
Water-BasedDRY FILM
Anaerobic-cure resin in a water-carrier film. Inert until air is excluded by mating thread compression.
STRENGTH RATING
HighVIBRATION-RATED
Designed to maintain preload under sustained vibration loading. Removal requires extended torque or heat.
TEMPERATURE RANGE
Up to 400°FCONTINUOUS
Continuous-service ceiling to 400°F — higher than Dri-Loc 200. Short-duration excursions above this tolerated; consult engineering for sustained service beyond 400°F.
CURE MECHANISM
AnaerobicRT · ON ASSEMBLY
Cure begins when air is excluded by thread engagement. No oven step. Initial cure within minutes; full cure within 24 hr.
SUBSTRATE COMPATIBILITY
Plated & BrightSTOCK
Optimized for zinc-plated, electroplated, and bright-finish fasteners where 200 Yellow’s phosphate-and-oil formulation may underperform. Not the primary choice for raw phosphate-and-oil; use Dri-Loc 200 for those.
VIBRATION RESISTANCE
YesSUSTAINED
Validated against industry-standard cyclic-load tests. Maintains preload through extended duty cycles.
REUSABILITY
NoSINGLE-INSTALL
Film is consumed at install. For reusable mechanical lock, see Bradley Nylon Patch.
VISUAL ID
Yellow PigmentQA-INSPECTABLE
Color-coded for batch inspection. Pigment is part of the formulation — consistent across the fastener length.
FASTENER SIZE RANGE
M3–M36#4 – 1.5 IN
Coatable across the standard fastener-size envelope. Larger or specialty sizes — consult engineering.
MANUFACTURER SPECS