Expand-A-Lock.
Pre-Applied · Expands 20–50% on Cure · Penetrates Where Conventional Threadlockers Cannot
A unique pre-applied microencapsulated expanding thread locker and sealant. Expand-A-Lock increases in volume 20 to 50% on installation — actively penetrating the gaps in fastener threads that conventional threadlockers leave unfilled. Dry to the touch before assembly. Activated by thread engagement. Locks and seals in one compound. 300°F rated. Not reusable.
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.
FUNCTION
LOCK + SEAL
EXPANDING
EXPANDS
20-50%
ON CURE
TEMP RANGE
300°FMAX
CONTINUOUS
VIBRATION RES.
YES
UNDER SHOCK
REUSABLE
NO
SINGLE INSTALL
Fills the gaps conventional threadlockers leave behind — then expands to stay there.
Conventional pre-applied threadlockers work by filling the space between mating thread crests and roots. They work well for standard thread fits. But some fastener applications — pipe plugs, air fitting connectors, compressor fittings, and cooling connectors — involve threads with larger gaps, looser fits, or annular spaces that standard threadlocker films do not fully penetrate.
Expand-A-Lock addresses this directly. The compound is microencapsulated and pre-applied to the fastener in the same dry-to-touch format as other ND grades — dormant in storage, activated by thread engagement. When threads engage at assembly, the capsule walls break, the compound releases, and it begins to expand. The expansion into unfilled thread gaps and voids creates a more complete lock-and-seal than conventional threadlockers achieve on these applications.
The 20 to 50% volume expansion is the defining performance characteristic. The compound penetrates gaps that remain partially or fully unfilled by standard threadlocker films, providing both locking and sealing of the thread interface — critical for pipe plugs and fitting connectors in pressurized systems where an incomplete seal is a failure. Vibration resistance and shock resistance are specified directly in ND Industries documentation for Expand-A-Lock.
Expand-A-Lock is not reusable. The expansion of Expand-A-Lock into thread gaps creates a more complete fill that is not designed for repeated disassembly and reinstallation. Specify Expand-A-Lock for fittings and plugs that will remain in service, not for assemblies that require regular access.
SPEC AT A GLANCE
Why engineers reach for Expand-A-Lock
The only pre-applied thread locker in the Bradley catalog that expands on cure. 20-50% volume expansion fills gaps conventional threadlockers cannot reach — for pipe plugs, air fittings, compressor connections, and cooling connectors under shock and vibration.
- PRODUCTND Industries Expand-A-Lock
- BRANDND Industries
- MECHANISMMicroencapsulated expanding compound
- EXPANSION20-50% volume increase on cure
- FUNCTIONLock + Seal (dual)
- TEMP300°F rated
- VIBRATION RES.Yes — under shock and vibration
- REUSABLENo — single install
- KEY APPLICATIONSPipe plugs · Air fittings · Compressor fittings · Cooling connectors
- VS OTHER ND GRADES593S/1193S = standard fill. Expand-A-Lock = expanding fill. Not interchangeable.
The numbers, plainly.
The full datasheet is available below — these are the values engineers most often need before specifying.
PRODUCT
ND Industries Expand-A-LockGREEN
Unique expanding microencapsulated thread locker and sealant from ND Industries — the only product in the Bradley catalog that expands on cure. Not interchangeable with the standard ND 593S or 1193S grades.
MECHANISM
Expanding MicroencapsulatedUNIQUE IN CATALOG
Microencapsulated compound that expands 20 to 50% in volume on cure after thread engagement releases the compound. Penetrates unfilled gaps and voids in thread interfaces that conventional threadlockers do not reach.
EXPANSION
20 to 50%VOLUME ON CURE
The defining specification. The compound actively expands after activation, filling the thread gap more completely than a standard threadlocker film. This expansion is what makes Expand-A-Lock the appropriate choice for pipe plugs and fitting connectors.
FUNCTION
Lock + SealDUAL
Both locks the fastener against vibration and shock loosening and seals the thread interface against fluid and gas migration — in one expanding compound.
TEMPERATURE RANGE
300°FMAXIMUM
Maximum service temperature of 300°F. Consistent with the ND 593S and 1193S grades and with most Dri-Loc grades.
VIBRATION RESISTANCE
Yes+ SHOCK RESISTANCE
Rated for vibration resistance and specifically noted for shock-and-vibration applications in ND Industries documentation. The expanded compound fills thread gaps that could otherwise allow movement under shock loading.
REUSABILITY
NoSINGLE INSTALL
Not reusable — unlike the ND 593S and 1193S structural adhesive grades. The expansion into thread voids creates a more complete fill that is not designed for repeated disassembly. Specify for permanent or long-service-life applications.
KEY APPLICATIONS
Pipe Plugs · Air Fitting Connectors+ COMPRESSOR + COOLING
Engine pipe plugs, air fitting connectors, compressor fittings, and cooling connectors — the application list directly from ND Industries Expand-A-Lock documentation.
MANUFACTURER SPECS