Warning! - Installing step/nerf bars

[dmurdock]

I bought some nerf bars from ebay that somebody else had posted about. They are actually excellent bars (quality,etc. . ) and about 1/4 the price buying retail (same exact bars). HOWEVER, the installation hardware includes new longer cab mounting bolts which are 4-8 grade and the factory cab mount bolts are 10-9 grade. I would strongly recommend buying the correct bolts when installing bars, etc... (cost me an extra $12 for the 4 correct bolts locally).

 

[TRCM]

got a link ?? I'm looking for some bars myself.

 

[dmurdock]

https://www.turbodieselregister.com/forums/showthread.php?t=136887&page=1&pp=15



Except for the sub-par body bolts, the kit is top notch.

 

[dhill]

"I bought some nerf bars from ebay that somebody else had posted about. They are actually excellent bars (quality,etc. . ) and about 1/4 the price buying retail (same exact bars). HOWEVER, the installation hardware includes new longer cab mounting bolts which are 4-8 grade and the factory cab mount bolts are 10-9 grade. I would strongly recommend buying the correct bolts when installing bars, etc... (cost me an extra $12 for the 4 correct bolts locally). "







I've never heard of 4-8 grade bolts or 10-9 grade bolts. They must be some kind of automotive grade. I've worked in maintenance in industry for over 30 years. Grade 2 bolts should not be used for anything structural, grade 5 are industry standard and grade 8 are not used much, only in special apps. Power plants use some stronger fastners, but I've never seen them used where I have worked.



The chart below shows the proof load and tensil in psi. Grade 5 are pretty tuff. Unless you had a couple of real heavy weights trying to get in on the same side and started bouncing on the nerf bar I dought if you'ed have a problem







No Markings

Grade 2

Low or Medium Carbon Steel

55,000 psi Proof Loading

74,000 Minimum Tensile Strength (psi)



3 Radial Lines

Grade 5

Medium Carbon Steel, Quenched and Tempered

85,000 psi Proof Loading

120,000 Minimum Tensile Strength (psi)





6 Radial Lines

Grade 8

Medium Carbon Alloy Steel, Quenched and Tempered

120,000 psi proof Loading

150,000 Minimum Tensile Strength (psi)





Dave

 

[dmurdock]

X. X is the metric standard for grading bolts. 10. 9 isn't 10 point 9, it's like 10 and 9. I looked it up a while back and basically metric bolts have 2 grades (tensile and something else). 10. 9 is the SAE equivalent of grade 8. The bolts that come with the bars are 4. 8 and I think they are even below the equivalent of a grade 5. The reason I say not to use the cheapies with the bar has nothing to do with the bars coming off. . i'm worried about the cab becoming seperated from the frame in the event of a bad collision.

 

[DieselDoghouse]

OR - if the bolts are inferior grade and you EVER have to back them out they'll snap and you'll curse, cry, roll up fetal, and then have to unmount part to your cab just to extract the stubs (sound like I've been there??). Happened with a set of Smittybilts which, BTY, I'll NEVER shop again. OH, the 10-9 Mopar bolts that came with the truck - they backed out NO problem!!! Your point is well taken!!

 

[JCasper]

I have already installed mine with the bolts that came with the kit. So that I don't have to pull a bolt out and head to the auto parts store, do you know what size and length bolt I need to get so I can pick one up some day in the near future.



Thank you, Joe