What Are LET-LOK Tube Fittings and How Do They Work?


Since the 1950’s the HAM-LET Group has been developing the most advanced tubing that fully guarantees leak-tight systems. The group’s LET-LOK® brand still leads the market when it comes to high-quality leak-tight tube fitting systems.

What are LET-LOK® fittings?

LET-LOK® tube fittings encompass a wide range of front-line, industrial-standard devices used to grip and seal tubing. These pipe and tube fittings are offered in a variety of materials to suit every kind of industrial application, especially those operating under high-pressure and severe conditions.

Industry experts have poured several decades researching, developing and manufacturing the LET-LOK®, the results of which are tube fittings that meet the fast growing call for superior products that withstand use in high-performance and high-pressure vacuum environments, such as power, petrochemical, nuclear, fluid, electronic, and other major industrial applications.

How LET-LOK® works

LET-LOK® tube connectors are precisely custom-made for ease-of-use. Assembly is very simple and requires just introducing the tube into the complete assembly until the tube bottoms-out against the fitting body. The two ferrules are then driven forward between the fitting body and the nut and through the mechanical force created by revolving the nut from left to right. The back ferrule is pushed against the tapered rear of the front ferrule while the front ferrule is driven by force it into the tapered body’s mouth.

The back ferrule is radially swaged inwards on the tube while lifting the front ferrule out to form a complete seal on the tapered body surface. Next, the 11/4 and 3/4 turn (dependent on the sizes) of the nut from the hand tight position, guarantees reliable drive of the sealing members. This also ensures an active seal against ultra-high vacuum and high pressure environments.

Tried & Tested

HAM-LET honors safety as a crucial factor. The company provides users with a large amount of information and tips to make certain that they choose a product that suits their application and will achieve supreme results in the safest and most secure manner. In gas applications, for example, it is best to choose tubing with greater wall thickness for more efficiency and safety. It is vital that the customer select products appropriate for their exact application requirements and that they perform correct product installation, operation and maintenance. Moreover, for personal safety, when choosing a connector it is important to take into consideration material compatibility, application details, and product ratings.

Every LET-LOK® tube fitting has been subjected to — and passed — a variety of severe tolerance tests, including those for vacuum, vibration, temperature, high-pressure, and impulse. Furthermore, the fittings are produced according to demanding standards using advanced computerized automation and have verified that they are robust enough to withstand each high-pressure condition. The secret behind their leak-tight assembly lies in their mechanical advantage and geometry.

In addition LET-LOK® fittings are supported by HAM-LET‘s pledge to provide the maximum quality-control standards and expert workmanship!