customblackbird

iTrader: (15)

Looking for a little more room around my 521 BBF and always wanted a tubular K-member. Found a good deal on a moly racecraft complete kmember for about the price of the UMI standard mild steel version. MAIN REASON is not for dropping weight but more room and the loss of weight is next. I already have UMI tubular Aarms and this would finish off my full tubular suspension.

I know moly isn't the best for street use and the car will be mostly street driven to shows etc but might see 500 miles a year. So do I grab the moly kmember as racecraft has great feedback or do I pony up the same amount for the UMI steel standard version not the road race version. This deal needs to happen quick.

plum92_camaro

If damaged, mild steel will bend, moly will just break.

customblackbird

iTrader: (15)

Thats an interesting comment… if mild steel is damaged it would most likely fail. But point being that would moly fail from regular street driving or fatigue over time for the life span of the material. Basically does mild steel have a longer life span than moly.

plum92_camaro

I asked the same question about torque arms and other rear suspension parts that come in moly or mild steel and thats what they (i think it was UMI) told me. Moly is harder, stiffer, and less flex but will break/snap/crack instead of bend when damaged (so hard its brittle). mild steel will bend before it breaks and is susceptible to some flex.

Does this make more sense? Sorry, I was in a hurry when I made the first post.

customblackbird

iTrader: (15)

From what Im reading is that moly has a higher fatigue life than mild steel, stiffer, harder and flexes more (hence why its used heavily in the aerospace industry and bc its lighter than steel and stronger). But its more expensive than mild steel and requires more expensive TIG welding than places like to use bc of production costs and time.

572_Rat

I sold my A/D to a friend, my car was made with 4130 chrome moly, Kelly crashed the car at 200 mph rolled 14 times on the track and the car held together, the only thing that happened him is that he was burned on his back because he was running alcohol and the track crew did not realize he was burning at first. The roll cage did bend a bit, but never broke.
That is why my K-member is made of chrome Moly

plum92_camaro

Glad you found the answer. Now I'm a little upset they didn't give me that good of info when I asked the same question about a torque arm. I should have said moly is stronger. I knew that. But didn't know it was lighter.

customblackbird

iTrader: (15)

Its lighter for its strength. Basically Mild steel DOM is .120" wall thickness, moly can go .085" wall thickness and have the same strength. Basically you pay more for the better material and get 20% weight savings. So my moly .085" wall Kmember weighs 20% less than the same mild steel version but have the same strength (since they have to run the thicker .120" wall thickness for strength). Now if you ran the same .120" wall thickness in Moly and mild steel they would both weigh the same but the moly version would be MUCH MUCH MUCH 2x stronger.

plum92_camaro

Lol, why did you ask if you know all this?

customblackbird

iTrader: (15)

Well I knew everything but I kept hearing that moly wasn't good for the street as its more brittle. Makes sense, since my titanium wedding band if deformed even the smallest amount (vise grip video with only slight pressure) will shatter. Titanium as we all know is incredibly strong and much more than mild steel and moly but it's weak once u overcome the stiffness and deform it.

plum92_camaro

lol, thats why i got a tungsten carbide wedding band!!

customblackbird

iTrader: (15)

Tungsten carbide is titanium! Lol. I got one too but it Def says titanium on the inside of the band. Yours will shatter if u deform it even the little bit! Be careful.