LET-LOK TUBE FITTINGS – What They Are and How They Work


To ensure leak-tight systems, it is important to carefully select high-quality tubing, such as those developed by the HAM-LET Group since 1950. Today, the group’s LET-LOK® brand leads the market as the most advanced, high-quality, line of leak-tight tube fitting systems available.

A Look at LET-LOK®
LET-LOK® comprises a vast range of cutting-edge, industrial-standard mechanisms used to seal and grip tubing. These tube and pipe fittings are available in a variety of materials for every type of industrial application, especially where severe conditions and high pressure exist.

In fact, tremendous efforts in research and development over the last five decades by industry experts have gone into the manufacture of these superior products. The results are products designed to meet the rapidly increasing demand for tube fittings that can withstand use in high-pressure, vacuum, high-performance environments, such as petrochemical, fluid, power, nuclear, electronic, as well as other major industrial settings.

The How of It
LET-LOK® connectors are specifically tailored for ease-of-use. Assembly is incredibly simple and merely requires inserting the tube into the complete assembly until the tube bottoms-out against the fitting body. Next, the two ferrules are driven forward between the nut and fitting body using the mechanical force created by rotating the nut clockwise. The back ferrule is driven against the tapered rear of the front ferrule and the front ferrule is driven by force into the tapered mouth of the body. The rear ferrule is swaged radially inwards on the tube while lifting the front ferrule out to form a full-faced seal on the tapered surface of the body. The 11/4 and 3/4 turn (depending on the sizes) of the nut from the hand tight position, assures consistent drive of the sealing members. This further ensures an effective seal against high pressure as well as ultra-high vacuum conditions.

Tried & Tested
HAM-LET regards safety as an essential component. The company provides a great deal of information and tips for users to ensure that they select a product for their applications that will achieve maximum results in the most safe and secure way. For example, in gas applications, it is recommend to select tubing with greater wall thickness for greater safety and efficiency. It is essential for the user to choose products suitable to their specific application requirements and to ensure correct product installation, operation and maintenance. Additionally, to guarantee personal safety, points to consider when choosing a connector include application details, material compatibility, and product ratings.

Each fitting has also been subjected to — and passed — a range of stringent tolerance tests, including those for high-pressure, vacuum, vibration, impulse and temperature. Moreover, the fittings, which are manufactured to exacting standards using state-of-the-art computerized automation, have proved to be strong enough to withstand every high-pressure condition. The secret to their leak-tight assembly lies in their mechanical advantage as well as geometry.

Last, but not least, all LET-LOK® fittings are backed by HAM-LET‘s commitment to the highest quality-control standards and skilled craftsmanship!