Lock nuts at 1-1/4 inch trade size are essential for securing conduits and fittings in metal enclosures and plumbing setups. This guide highlights five durable options to fit rigid/IMC conduit and related fittings, helping buyers select the right material for corrosion resistance, strength, and installation ease. The top picks cover steel, brass, and stainless steel varieties to suit different environments and applications. Each option is best for specific scenarios, from heavy-duty electrical enclosures to high-moisture plumbing connections.
Summary table of chosen products:
- RACO 1195 Locknut — 1-1/4″ trade size, steel, zinc-plated; best for general outdoor or harsh environments.
- Arlington 404 Plated Steel — 1-1/4″ trade size, plated steel; best for rigid/IMC conduit in industrial settings.
- uxcell Brass Lock Nuts — G1-1/4″-11 female hex, brass with silicone washer; best for corrosion resistance in water fixtures.
- uxcell Cast Stainless Steel Hex Locknut — 1-1/4″ NPT, 304 stainless steel; best for leak resistance and durability.
- DERNORD Cast Pipe Fitting Stainless Steel 304 Hex Locknut — 1-1/4″ NPT; best for high-strength, corrosion-resistant plumbing connections.
RACO 1195 Locknut for Rigid/IMC Conduit — 1-1/4″ Trade Size
- Brand: RACO
- Material: All steel construction with zinc electro plating
- Trade Size: 1-1/4 inch for Rigid/IMC conduit
Best for: General electrical and conduit installations requiring robust mechanical protection and corrosion resistance. This locknut is straightforward to install and suited for metal enclosures and rigid conduit systems. Caution: All-steel construction can conduct heat and may require caution around high-temperature environments.
Arlington 404 Plated Steel Threaded Conduit Locknut — 1-1/4 Inch
- Brand: ARLINGTON
- Material: Plated steel
- Trade Size: 1-1/4 inches; 2.08-inch diameter, 0.187-inch thick
Best for: Rigid and IMC conduit fittings in metal enclosures; UL listed and CSA certified. Use when a certified, durable solution is required. Caution: Heavier than some alternatives, which may affect ease of handling in tight spaces.
uxcell Brass Lock Nuts — G1-1/4″-11 Female Hex
- Brand: uxcell
- Material: Brass with silicone washer
- Thread: G1-1/4″-11; Outer diameter about 2.05 inches
Best for: Faucet fixtures and single-hole installations where corrosion resistance and a tight seal are needed. Provides a silicone washer for improved leak resistance. Caution: Not compatible with PT or BSPT threads; brass is softer than steel and may deform under excessive torque.
DERNORD Cast Pipe Fitting Stainless Steel 304 Hex Locknut — 1-1/4″ NPT
- Brand: DERNORD
- Material: Stainless steel 304
- Connection: NPT threaded
Best for: High-strength, corrosion-resistant connections in plumbing and gas fittings where stainless steel is preferred. Caution: Data indicates stainless steel 304; consider environment exposure to chloride in sensitive applications, as corrosion risk can increase in certain conditions.
uxcell 3Pcs Cast Pipe Fitting Hex Locknut — 1-1/4″ NPT, 304 Stainless Steel
- Brand: uxcell
- Material: 304 stainless steel
- Package: 3 pieces; hex width about 46mm
Best for: Projects needing multiple locknuts with tight seals for NPT connections and improved durability. Caution: As stainless steel, may be more expensive than plated steel options.
Buying Guide
What material is best for 1-1/4 lock nuts?
Choose steel for strength and cost efficiency in dry environments. Brass offers excellent corrosion resistance for water-related applications. Stainless steel 304 provides strong corrosion resistance in moisture-rich or corrosive settings, though at a higher cost.
What thread types and fittings apply?
Match locknut threads to your conduit or pipe fittings: NPT (National Pipe Tapered) is common in plumbing; G or PT threads appear in some plumbing and fixture applications. Ensure compatibility with the mating connector to prevent leaks.
When is a washer or seal important?
A silicone washer or O-ring groove can improve leak resistance, especially in faucet or fixture connections. If a washer is included, factor it into the installation and potential re-tightening needs over time.
Which products are best for electrical conduits?
Locknuts designed for rigid or IMC conduit and UL-listed or CSA-certified options provide reliable termination in electrical enclosures. Look for steel or plated steel finishes for durability in industrial environments.
Durability and installation concerns
Stainless steel options resist corrosion longer but may require more effort to torque. Brass is softer but excellent for corrosion-prone water applications. Consider installation space and torque requirements when choosing between hex, flange, or standard locknut designs.
What if I need multiple locknuts?
Multi-pack options from uxcell offer cost-effective solutions for repeated installations. When selecting multiple units, verify thread size compatibility with your fittings to avoid mismatches.
Summary: quick comparison by use-case
- Best for general electrical conduit: RACO 1195 (steel, zinc-plated)
- Best for certified, heavy-duty conduit work: Arlington 404 (plated steel)
- Best for corrosion resistance in water fixtures: uxcell Brass Lock Nuts
- Best for leak-resistance and durable plumbing connections: uxcell 3Pcs Cast (304 SS)
- Best for high-strength, corrosion-prone environments: DERNORD 304 SS Hex Locknut
FAQ
- What is the standard size for a 1-1/4 lock nut?
It corresponds to a 1-1/4 inch trade size for conduits and fittings, commonly used with rigid or IMC conduit systems and 1-1/4″ NPT or G threads in plumbing fixtures.
- Are stainless steel locknuts worth the extra cost?
Yes for long-term corrosion resistance in moist or salty environments, but weigh cost against installation needs and expected lifespan.
- Can I use a brass locknut on metal conduits?
Brass works well for certain water-related fixtures and corrosion-prone environments but may not be as strong as steel for heavy conduit loads.
- Do locknuts require thread sealant?
Sealants or gaskets are sometimes used with certain thread types to prevent leaks; follow the fixture manufacturer’s recommendations.
- Which locknut is best for single-hole faucet installations?
Brass locknuts with silicone washers are designed for faucet stability and leak resistance in single-hole installations.
- Can I mix different materials for the same system?
Mixing metals is possible but may require precautions against galvanic corrosion; ensure materials are compatible with the intended environment and media.