Product Feature
HAM-LET® GROUP has produced high quality tube and pipe fittings in various materials for high pressure applications since its establishment in 1950.

For almost five decades, through tremendous efforts in research and development, HAM-LET® has gained an excellent reputation as a leading manufacturer of high pressure instrumentation products.

The LET-LOK® range of connectors has been developed to fill the rapidly increasing demand for tube fittings suitable for high pressure use in environments such as petrochemical, fluid, power, nuclear, electronic, as well as other major industries.

LET-LOK® tube fittings have been carefully manufactured and tested to withstand the demands of high performance tube fittings, such as high pressure, impulse, vibration, vacuum and temperature. These tube fittings are manufactured to exacting tolerances using the most modern and advanced computerized automation. One of the major conditions to producing these precision machined fittings is by maintaining stringent quality control in conjunction with skilled craftsmen.

LET-LOK® tube fittings are composed of four parts:
1) body, 2) front ferrule, 3) back ferrule, and 4) nut.



How LET-LOK® Fittings Work
The Let-Lok® tube fitting is a mechanism used for both sealing and gripping tubing. Through mechanical advantage and geometry the fitting produces a leak-tight assembly. To assemble, simply insert the tube into the complete assembly until the tube bottoms-out against the shoulder of the fitting body. 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 (3) is driven against the tapered rear of the front ferrule (2) 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 turn on the nut from the hand tight position assures consistent drive of the sealing members. This ensures an effective seal against high pressure as well as ultra high vacuum conditions.

LET-LOK® Installation Instructions



LET-LOK® fittings are supplied assembled, finger tight. Disassembly before use can allow the entry of dirt or other particles.

1. Insert the tubing into the Let-Lok® fitting. Check that the tube rests firmly on the fitting shoulder and that the nut is finger tight. At this point it is recommended that a scribe mark be drawn on the hex of the nut extending onto the fitting body. This mark will serve as an indicator for the starting point and proper pull-up.

2. Tighten the nut. (see Fig. A &B) 1 1/4 turns of the nut is required for 1/4" (6 mm) and higher. 3/4 turns of the nut is required for 3/16" (4 mm) and lower.



Reassembly Instructions
Let-Lok connections may be disconnected and remade repeatedly, without loss of leaktight seal.

1. Before disconnecting, mark the position of the nut in relation to the fitting body.
2. To reassemble, use a wrench to tighten nut to original position.
3. Tighten slightly with wrench until a slight rise in torque is felt.