hi-tigue 1

[uwechristiaens]

hello, I'm from the Belgian Airforce, we fly hercules C-130H models. In my tech doc I can't find any torque-value's for the kfn542 nuts used to tighten the hi-tigues with diameter 3/16 and 1/4.

 

[bf109g]

Hi Uwe,

Based on my experience with Boeing/Douglas products, there should be something in Chapter 51 of the SRM that allows you to use nuts instead of the standard collar. Unless specifically shown otherwise, you would torque to standard specs for that pin/bolt diameter.

Hope that helps.

 

[tbuelna]

check with the manufacturer:

http://www.hi-shear.com/fastener_hlt_stds.htm

Hi-Tigue pins are designed to be installed with a certain collar that has a hex shaped drive element that shears off at a predetermined installation torque. The standard collar is finely engineered and duplicating that same installation torque/preload with a different nut will likely require some test work.

Of course, you could always try contacting Lockheed Martin. If the nut you specify is an acceptable substitution, they should have an established procedure for installing it.

 

[rb1957]

i'd've thought it would be enough to apply Hi-Tigue's maximum torque with a torque wrench

 

[RPstress]

I'd go a bit farther; torque is not all that reliably related to tensile preload unless the things like lube, etc., are controlled tightly.

 

[Rob130]

TO 1C-130-A specifies 50-60 inlb for 3/16 and 100-115 inlb for 1/4 in KFN542 nuts. Found in figure 51-70-09 sheet 2 of 8

 

[Rob130]

SMP 583 specifies 35-45 inlb for 3/16 and 100-115 inlb for 1/4 in KFN542 nuts. Found in figure 51-70-12 sheet 2 of 5