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Part# 05-12626
MFR Model# NAS1523-8B
I.D.O.D.Part Number


Stat-O-Seal NAS1523

The NAS 1523 Stat-O-Seal is designed with a pre-calculated interference factor built into the teardrop shaped elastomeric seal designed for applications requiring NAS 1523 conformance. The cross-section free height of the rubber is greater than the metal retainer, providing the proper compression without squeezing the seal beyond its elastic limit.

NAS 1523 Stat-O-Seal Features:

    Parker NAS 1523 Stat-O-Seals are one-piece, molded-in-place seals with the rubber sealing element mechanically and/or chemically bonded to the metal retainer. Parker's “Splined and Coined” mechanical bonding feature is used on many 600, NAS1523 and 610 series sizes. This feature ensures a positive attachment of the rubber to the retainer, eliminating missing or loose seal elements associated with bonded seals. Stat-O-Seals are designed to seal beneath the head of the fastener as shown for both internal and external pressure and vacuum systems.
NAS 1523 Stat-O-Seals offer users long and reliable service, a high degree of reusability and easy assembly.

The NAS 1523 Stat-O-Seal's unique features provide many advantages and benefits as shown below:
    • No machined O-ring grooves are required in the mating flange
    • Precisely controlled optimum percent squeeze eliminates over compression
    • The retainer edge is visible after installation allowing for easy visual inspection and reducing failures caused by missing seals
    • The self-centering design provides easy and accurate placement of the seal
    • The solid metal to metal contact improves joint stability and eliminates re-torqueing
    • Long reliable service and a high level of reusability
    • Rubber/bolt interference provides for easy assembly
As the fastener is installed into the mating hardware, the NAS1523 Stat-O-Seal is compressed down to the retainer thickness. The retainer provides a positive alternate load path for fastener torque and forms a protective gland area for the confinement of the seal in a controlled state. Since the elastomer seal cannot move outward, the mass of the seal is forced inward against the shank of the fastener and against the mating surfaces, creating a positive seal. This principle is known as controlled confinement sealing. The diameter of the fastener head should always exceed that of the maximum "E diameter" in order to preserve this principle.

California Prop 65 Warning Symbol

WARNING: Cancer and Reproductive Harm -


  • Retainer Material: 4130 Chrome Molybdenum steel, SAE AMS 6350, heat treated to Rockwell C26 to C33
  • Elastomer Material: N406-60 Nitrile
  • Minimum Working Temperature (F): -40
  • Maximum Working Temperature (F): +225
  • Certificates: SAE AMS-R-6855, Class 1, Grade 60
  • Coating Option: Cadmium Plated Per SAE AMS-QQ-P-416 Type II, Class 2 Dyed Black


These seals work great!

Aloft A Verified Purchase


August 15, 2023


Please note,'s personnel are not certified aircraft mechanics and can only provide general support and ideas, which should not be relied upon or implemented in lieu of consulting an A&P or other qualified technician. assumes no responsibility or liability for any issue or problem which may arise from any repair, modification or other work done from this knowledge base. Any product eligibility information provided here is based on general application guides and we recommend always referring to your specific aircraft parts manual, the parts manufacturer or consulting with a qualified mechanic.