i am getting ready to order DOM for my NHRA roll cage going in a crx and i need to know if i go off the wall thickness for chrome moly or if i go off the wall thickness of mild steel, since DOM is stronger...thanks in advance for any info

 

DOM is how they manufacture the tubing....

Drawn Over Mandrel

 

i know that...im asking that i am going to have a roll cage built in my car according to NHRA rule book specs and i need to know since they dont mention what wall thickness to use for DOM do i go off the rule book wall thickness for chrome moly tubing or mild steel?

 

if its mild steel it needs to be the mild steel spec f its moly then its the moly spec

dom has nothing to do with it. It is a manufactureing process and doesn't change the required wall thickness for the material used if your going to use dom sild steel the try to get .125 wall rather then .120. They get really **** about the wall thickness on mild steel and can/will fail anything thats less then .117.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by KFMRC &raquo;</TD></TR><TR><TD CLASS="quote">if its mild steel it needs to be the mild steel spec f its moly then its the moly spec

dom has nothing to do with it. It is a manufactureing process and doesn't change the required wall thickness for the material used if your going to use dom sild steel the try to get .125 wall rather then .120. They get really **** about the wall thickness on mild steel and can/will fail anything thats less then .117.</TD></TR></TABLE>

thanks for the info...i seen somewhere on here they might ban mild steel in the future?? any truth in that?

 

They would sooner ban Chromoly and just mandate DOM mild steel.

 

allright just making sure cause i only want to do my cage once...thanks

 

Is ERW legal for a full cage if it meets the minimum spec for mild steel?

 

Yes it is but will have an ET limit of 7.50 and is even heavier then the 120-125wall
dom. Don't even think of using anything less then 135 wall in ERW becasue the chance of a tube measuring thin and the bar failing is really good.

 

http://www.nhra.com/contacts/tech_faq.html

This page tells you all about the thickness requirements. 0.083 is the thickest you would need if using chrome moly