Parker 61AB-4 Compression Tube Nut Brass 400 Psi

Product Description

The PARKER 61AB-4 is a brass compression tube nut designed to secure compression fittings in pneumatic, hydraulic, and fluid-transfer line assemblies. It provides a leak-resistant mechanical connection by threading onto a compression fitting body and drawing a ferrule against the tubing OD. With a 0.256 inch inside diameter, a maximum working pressure of 400 psi, and a rated temperature range of -65 degrees F to 250 degrees F, this nut suits a wide range of service conditions. It meets DOT FMVSS571.106 and SAE J246 standards, making it appropriate for brake and fuel line applications where regulatory compliance is required. Licensed plumbers, HVAC technicians, and fleet maintenance professionals are the primary installers.

This compression tube nut is used in residential, commercial, and light industrial systems where tubing must be terminated or joined at a fitting body without solder or flare. Common applications include automotive brake lines, fuel delivery tubing, and compressed-air or fluid-control lines. Its brass construction resists corrosion in wet and mildly chemical environments. The DOT and SAE compliance ratings make it well suited for on-highway vehicle brake system service as well as stationary fluid-power plumbing where those standards are specified by the design engineer or authority having jurisdiction.

Key Features

• Brass construction for corrosion resistance and reliable sealing in compression connections
• 0.256 inch inside diameter sized for standard compression tube assemblies
• 400 psi maximum working pressure for pressurized fluid and brake line service
• Wide service temperature range: -65 degrees F to 250 degrees F
• Meets DOT FMVSS571.106 and SAE J246 standards for brake and fuel line compliance
• Compression end connection — no solder, flare, or special tooling required for assembly

Compatibility

Designed as an OEM-style compression tube nut for use with standard compression fitting bodies and ferrules in fluid-transfer, pneumatic, and DOT-compliant brake line assemblies.

Installation Notes

Installation is typically performed by licensed plumbers, HVAC technicians, or qualified fleet maintenance professionals. Shut off all system pressure and depressurize the line completely before disassembly or installation. Thread the nut onto the fitting body by hand first to confirm proper thread engagement, then tighten with an appropriately sized open-end wrench — avoid over-tightening, which can crack the ferrule or distort the tubing. On DOT brake system applications, follow applicable FMVSS and vehicle manufacturer service procedures.