Jack

slav80

slav80

Well-known member
Joined
Jun 15, 2010
Messages
231
Reaction score
0
What is correct elevation on the screw jack?

---------- Post added at 05:48 AM ---------- Previous post was at 05:46 AM ----------

I need to resolve a dispute here cos i think one third of total length was a rule of a thumb. Cheers
 
slav80 said:
What is correct elevation on the screw jack?

---------- Post added at 05:48 AM ---------- Previous post was at 05:46 AM ----------

I need to resolve a dispute here cos i think one third of total length was a rule of a thumb. Cheers
Click to expand...

Yeah I think no less than a third of the thread shoud be inside the tube mate.
 
dont know but i would guess thats right! i try and get it as close as possible to the ceiling/steel etc.
 
Is it not marked on the screw, I was always told that is why you cant screw it up all the way.
 
Most screw jack have a crimp in them to the maximum height that you can go. I was always led to believe that this can unscrewed 2/3rds leaving the other 3rd inside the standard. Can dig the training stuff out if needed but carnt be arsed at the minute.
 
Quite right Steve, it's Sunday after all.:D
 
It might be Sunday but as im in the yard, jack 540mm thread travel 360mm so one third left in tube.
 
I'm teaching my granny to sook eggs here phil but it depends on what type you are talking about. As per usual the dimensions I am about to give are estimates as I too can't be bothered to check. The old cup-lok jacks have about 650ish thread on them with a further 300 smooth finish to stop you over screwing it and if memory serves I think they are 9t. The newer gen lok jacks we now get are threaded all the way up but crimped to stop you screwing it all the way up, they have about 500mm threaded length and 200mm above the crimp to go in the standard. I think the leg load for this type is 5 ton.

Clear as mud eh.:D
 
Depends on the type of jack used, the type I use is the SGB universal jack, overall lenght 860mm with a range of adjustment of 620mm, so as a minimum there would be 240mm in the standard. for heavier load bearing the adjustment is reduced for instance in formwork structures if jack extensions are kept below 350mm loads on the standard can be increased to 74kn with 1.5m lifts and 1.8m ledgers. The answer seems to be depending on the height/weight on the standards.
 
Design by calculation springs to mind, TG 20:08, i feel as if we are realy stuck between a rock and a hard place, What are we actualy allowed to do off our own backs now? Answer 'Jack sh1t'.
 
You must log in or register to reply here.
Top Bottom