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Hexagonal 316 stainless steel locknut with FNPT threads

Legend Valve

Legend Valve 416-166 1-1/4 in FNPT 316 Stainless Steel Locknut

SKU CH-7Z4D-FQASC

A 316 stainless-steel locknut with 1-1/4 in FNPT threads rated to 290 psi

  • Corrosion-resistant 316 stainless steel construction
  • Rated for 290 psi at -4 degrees
  • 1-1/4 inch FNPT thread connection
  • Legend Valve model 416-166 industrial locknut
  • California Proposition 65 chemical warning applies

Industrial Plumbing Locknut

The Legend Valve 416-166 is a 1-1/4 inch FNPT locknut made from 316 stainless steel. It is designed for industrial plumbing installations where corrosion resistance and thread security are required. This component suits maintenance engineers and pipefitters assembling or repairing pressurised systems. Buyers needing a different thread size or material grade will not find a match here.

Pressure Rating and Compliance

The fitting carries a 290 psi rating at the stated temperature reference. It meets the demands of standard industrial pressure lines within that limit. California Proposition 65 warnings apply because the product contains chemicals known to the state to cause cancer and reproductive harm. No noise or thermal data is relevant for this static mechanical component.

Installation and System Fit

The locknut uses a female national pipe thread connection to secure mating fittings in a pipeline. Its 316 stainless construction allows it to remain in service where lesser alloys would corrode. It requires a compatible male-threaded counterpart and appropriate thread sealant for a leak-free joint. The part adds no electrical or control function to the system.

Highlights

  • Corrosion-resistant 316 stainless steel construction
  • Rated for 290 psi at -4 degrees
  • 1-1/4 inch FNPT thread connection
  • Legend Valve model 416-166 industrial locknut
  • California Proposition 65 chemical warning applies

Specifications

BrandLEGEND VALVE

Questions about this item

How do I install the 1-1/4 in FNPT 316 stainless steel locknut without damaging the threads?

Thread the locknut onto the male FNPT fitting by hand until snug, then tighten with a wrench one to two turns further; over-tightening strips the tapered threads and causes leaks.

What maintenance or replacement will the 316 stainless steel locknut need over time?

Inspect the locknut periodically for corrosion, galling or cracked threads; replace it if the 316 stainless shows pitting or if the joint weeps at the rated 290 psi.

What is the first limit that appears when the locknut is used continuously at its 290 psi rating?

Sustained pressure at 290 psi can accelerate thread galling on the FNPT connection, so the mechanical integrity of the threaded joint becomes the limiting factor.

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