We take cryptocurrency — so the coins you hold can buy real hardware.Pay in crypto, spend it on real hardware. Free insured shipping worldwide over $399. Plain, unbranded boxes, sent from Germany.Free insured shipping over $399. Your rate is locked for 30 minutes once checkout opens.Rate locked 30 minutes. Every item sealed, serial-checked and covered by a 24-month warranty.Sealed, 24-month warranty.

Saved items Sign in
Blue Loctite 243 threadlocker bottle 1.69 fl oz

Loctite

Loctite 1329467 Primerless Threadlocker 243 Blue 1.69 fl oz

SKU CH-CW7R-PMFME

Primerless medium-strength threadlocker for metal fasteners up to 3/4 in, cures anaerobically in 10 minutes with 230 in-lb breakaway torque

  • Primerless formula speeds assembly on oily threads
  • Medium-strength hold rated at 230 in-lb breakaway torque
  • 10-minute working time allows precise positioning
  • Blue 243 series suits fasteners up to 3/4 in
  • 69 fl oz bottle covers multiple repair jobs

Threadlocker for common metals

LOCTITE 243 is a primerless, medium-strength anaerobic threadlocker supplied in a 1.69 fl oz bottle. It locks and seals threaded fasteners made from aluminum, brass, bronze, copper, iron, manganese, Monel, nickel, plated metals, stainless steel, steel and zinc. The blue formulation identifies medium holding power for general maintenance and assembly tasks. No primer is required before application on the listed substrates.

Working time and breakaway torque

The adhesive provides a 10 minute working window for positioning parts before curing begins. Once cured, it delivers a breakaway torque of 230 in-lb to resist vibration loosening. Its oil-tolerant chemistry allows reliable performance on threads that may have residual lubricants or protective coatings. Cure occurs anaerobically when confined between metal surfaces in the absence of air.

Bottle format and diameter limit

The bottle container suits bench-top use and controlled dispensing during repairs or production runs. The product is rated for fasteners up to a maximum thread diameter of 3/4 in. It is not intended for larger diameter bolts or for applications requiring high-strength permanent locking. Buyers needing primer-dependent formulas or higher temperature resistance should verify alternative grades.

How it compares

Measured against everything we stock in Caulking & Sealing Supplies, at today’s prices. Recalculated every night.

Price $35.99
Pricier than about 72% of the 631 comparable items (median $16.99).

Specifications

Product
Brand nameLOCTITE

Questions about this item

How do I apply the primerless threadlocker to a 3/4 in bolt, and what step do people skip?

Clean both threads, apply several drops of the blue 243 formula directly onto the engaged area, then assemble within 10 min; the step often missed is skipping primer on stainless or plated metals because this grade is primerless.

When will the cured threadlocker need to be replaced or re-applied?

The anaerobic cure is permanent until the joint is broken; re-application is only needed if the fastener is removed for service, at which point old adhesive must be cleaned off before fresh 243 is applied.

What is the first limit reached when a fastened joint sees continuous vibration and heat?

The bond holds up to 230 in-lb breakaway torque; sustained vibration or thermal cycling that exceeds this torque value will cause the fastener to loosen first.

More in Caulking & Sealing Supplies

Similar items