Parker Fluid Connector Group
Ferulok® Flareless Bite Type Fittings

Nuts, Ferrules, Locknuts

  • BU
  • TU
  • WLN


  • HBU
  • WBU
  • F5BU
  • FBU
  • GBU
  • TRBU
45* Elbows

  • V5BU
  • VBU

90* Elbows

  • EBU
  • WEBU
  • C6BU
  • C5BU
  • CC5BU
  • CBU
  • DBU

  • JBU
  • S6BU
  • R6BU
  • S5BU
  • R5BU
  • SBU
  • RBU
  • OBU
  • MBU


  • KBU

Plugs and Caps

  • PNU
  • FNU
Conversion Adapters

  • XHBU
  • XHBU2
Flange Adapters

  • BUHQ1
  • BUVQ1
  • BUEQ1

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Robust Port Stud: The adjustable port stud is manufactured with a longer locknut designed to cover the uppermost threads completely. Since the backup washer is never exposed to the upper threads, it cannot be damaged during assembly. During assembly, exposed upper threads, as common with fittings from other fitting manufacturers, can lead to a deformed backup washer that can pinch the o-ring and create an o-ring extrusion gap that has the potential to leak. The longer locknut also provides a greater grip area for the wrench. 

Visible bite: The style A (SAE 08115A) ferrule design allows for an easy inspection of the bite in the tubing. A verification can quickly be achieved which reduces time and assures proper assembly. This assurance also eliminates the risk of leaks and catastrophic failures.

Rear compression grip: The ferrule is also designed with a rear bevel to firmly hold the nut and tubing. This enhancement dampens the effects of vibration in the connection; thus extending the life of the joint.

Metal-to-metal sealing: The metal to metal sealing function broadens the range of both temperatures and media types. The temperature and media range of Ferulok is not limited by an elastomeric seal, but by the range of steel and stainless steel (see page T9 of the General Technical section for material temperature and media compatibility).

Superior Plating: Superior plating gives Parker steel tube fittings unmatched protection against red rust. In neutral salt spray test per ASTM B117, Parker Ferulok fittings substantially exceeded the SAE requirement of 96 hours to red rest.

No special tooling required: Neither flaring nor flanging tools are required to make a Ferulok connection. Smaller sizes of Ferulok can be assembled by a wrench thus reducing tooling costs and assembly time. However, portable presetting equipment is available for larger sizes and/or high production (see Section R of the catalog for equipment available).