HY-LOK is a extra part for metal shearing machine and press brake.the common connect between tube and tube is under welding.this way is cheap but it is easy to break.if the problem happen, you need non-stop welding and use sealing.now,there are a HY-LOCK, it can avoid the problem of welding. if you use it into metal shearing machine and hydraulic press brake,no doubt,it will improve their quality.but,lots of buyers place more attention to price,so,it is not possible for us to include this HY-LOK in the machine. because this HY-LOK needs to add about USD 800.as a result,we hope buyers can concern the details of parts,Not the price only.this fact is that we can use new parts into our machine,then, the buyer will complain our quality,actually,it is due to too much concern for price.