Install of oem tow hooks on a 14 Express

[Ken226]

ASTM A36 Carbon steel (commonly called mild steel).

However, any annealed state steel with a tensile yeild of 36'000psi or above will allow it to function correctly.

By correctly, i mean pull at least 1.5x the trucks weight and release the tow hooks in the event of a front end collision.

 

[DM1204]

ASTM A36 Carbon steel (commonly called mild steel).

However, any annealed state steel with a tensile yeild of 36'000psi or above will allow it to function correctly.

By correctly, i mean pull at least 1.5x the trucks weight and release the tow hooks in the event of a front end collision.

@Ken226 has me curious. Do you know what the psi on 7 guage steel is. I don't have any plans to use them for the intended purpose but if it came down to it it would be nice for them to work.

 

[Ken226]

@Ken226 has me curious. Do you know what the psi on 7 guage steel is. I don't have any plans to use them for the intended purpose but if it came down to it it would be nice for them to work.

The yeild psi has nothing to do with the thickness, but is dependant on the section area of the material in question.

Example, a36 yeild is 36000psi. A peice of stock 3/16" thick x 3/4" wide results in a section area of .141" squared, and will yeild (stretch) at a weight, in tension, of 5062 lbs.

But the weakest area of the bracket isnt in pure tension. It is in tension in 1 derection, compression in another, and has a bending moment as well.

Use 3/16 for lighter trucks, or 1/4 for heavier trucks. A thicker material will hurt nothing and add little to the cost.

 

[DM1204]

I forgot to add, my stress analysis was based on a material thickness of 3/16" or .1875" if i remember correctly. Its been awhile.

With mild steel, less than 3/16" @ 1.5x the weight of a ram 1500 sport could result in fatigue and buckling at the area between the outside hook screw slot and the outside edge of the bracket.

This stress analysis was done using Autodesk Inventor Pro HSM finite element analysis software.

Adjust the material and design to your own desires, but i'm on record here as not responsible for any failure resulting from design deviations .

So 7 guage steel being 3/16" it should be fine?

 

[Ken226]

Yes, itll be @ about minimum spec. 3/16 is .1875" precisely. Suppliers use the name "3/16", nominal, which isnt quite 3/16".

Itll beat minimum if thicker or better grade steel. But 7ga will more than take everything a hemi can pull.

Pulling on a single hook with a winch could exceed though.

About the same as stock brackets at minimum thickness, 3/16

 

[Ken226]

For 316 stainless steel youll get near double the ultimate tensile yeild @ about 70000psi.

 

[Ken226]

I'd rather buy than manufacture...so I'm 100% interested!

need them to be strong as I plan to USE them...

Smart guys like @Ken226 and @kad, thoughts on .179 304 Stainless for this?

304 is a chromium nickel, has similar ultimate tensile strength as 316 but better corrosion resistance.

Itll work fine, wont really be much if any stronger than 316, but less likely to rust. 304 is the stuff used in alot of food grade stuff like sinks and countertops.

For max strength, look at structural chomium molybdenum steels like 4130 or 4140.

 

[kad]

I'd rather buy than manufacture...so I'm 100% interested!

need them to be strong as I plan to USE them...

Smart guys like @Ken226 and @kad, thoughts on .179 304 Stainless for this?

Well, I appreciate the compliment, but my metallurgical knowledge is actually very slight. @Ken226 is the person you want to answer this.

-K

 

[Ken226]

4140 Chromoly has an ultimate tensile strength of 95,000 psi. Commonly used it racecar roll cages, wing spars in aerobatic aircraft and rifle barrels.

For a stainless with similar properties, 440c is tough as hell too.

Finding 4140 angle might be tough.

 

[bruiserRAM]

For 316 stainless steel youll get near double the ultimate tensile yeild @ about 70000psi.

So, will this still release allowing the front to crumple as designed, with the higher strength?

 

[JB1]

So, will this still release allowing the front to crumple as designed, with the higher strength?

Yes, the bracket is slotted so the hook would separate as oem designed. The hook itself has a bushing at the lower frame mount that also separates itself from the actual hook.

 

[kad]

No red on my truck except on the hemi badge

He might be thinking of mine...



-K

 

[MADDOG]

This thread has been cleaned up to remove the posts by a non-supporting vendor selling items on a commercial basis.

Also removed are any other posts made that quote the removed posts or discuss any aspect of a transaction to purchase the items offered.

It is suggested that all members review the rules of the forum.

 

[WilliamS]

He might be thinking of mine...



-K

Those are the ones.

 

[WTM75]

Well that sucks! Thought I was finally going to get the bracket to center the tow hooks on my Express.

 

[WilliamS]

Well that sucks! Thought I was finally going to get the bracket to center the tow hooks on my Express.

Yeah, i forgot you cant help other members without paying.

 

[Dice]

I was hoping for a set too.

 

[Rockhound]

Yea, I wanted a set too!

 

[Ken226]

Bummer!

 

[Arth]

Forgot about that. It's a free forum to use and support but if they don't get a hand in the transactions then no sales.