Cracked Tie Rod for 2600-Ton Press

Please give more informations: where is the crack, dimensions of the tierod section, aso.

The 1st thought is NOT to fix but to chnge since if the tie rod breaks the load on the other tierods is increased and it is a risk of total destruction. Even to work with a crach could lead to destrution since the cracked tie rod has a lower stifness and thus the other still intact will be over loaded. The plateaus will not be any more parallel under load and this can destroy the tool.

I was confronted several years ago with a similar problem at a much lower force level so that I know how things evoluate. In this special case the tool got a crack first due to alow grade material and a notch effect, because of it the press frame was not any more symetrically loaded and parts of it developped cracks due to the new load pattern. When I was consulted for expertise the frame was badly cracked and the tool totally destroyed.

Best thing for you to do is get the manufacturer to fix it. A 2,600 ton press isn't something to mess with if you don't know what you're doing.

As others have said, 1st contact the manufacturer. Do they offer repair service and to what extent. You will have to have the tie rod magna fluxed or x-rayed after the repair. It HAS to have some method of inspection or you will create a huge stress riser.

Check with used equipment manufactures for the industry you are in, can you exchange the tie rod for one off another press they may have. When this problem came up in the past, I usually had all the tie rods inspected and in some cases replace all 4. As previously state, by the time you noticed the crack, you may have done damage or severly weakened the others. I'd also check the parallelism of your platens.

The remark you made is very correct. The crack changing the tie rod stiffness the load distribution has been already changed and it possible that ALL tie rods are now over loaded and their life expectancy has been reduced.

It is also important to analyse and determine the reason for the crack. One can be a loose fastening of tie rods which lead to an increase of load on the cracked one. It is important to know after how many cycles the crack appeared and how it was detected.

If the crack is due to an assembly/maintenance error or even a design error the cost has to be supported by the organisation at the origin and not by the user.

That brings up another good point. Is this a hydraulic machine or electric machine and what's the clamping mechanism? I broke a wrist pin on a horizontal toggle clamp due to the tie bars not being installed correctly. (tie bar stretch was not correct) That then lead to a crack in the tie bar.

Root cause will be very important here to prevent further failure of other mechanisms in the machine.