Semi-Tactor Frame Material

Date 10-31-2005 18:31

quick comment -

Could be HSLA (high strength low alloy) steel.

Look for any labeling or warnings regarding NO drilling, welding, or grinding - that would be a dead give away.

By SA-200

Date 11-01-2005 02:38

Welds up with 7018.

By trevwelder Date 11-01-2005 04:29

I have welded a few that where aluminum. Ran into only one that was not aluminum, welded it with 7018 and it welded up fine.

By supermechanic (**)

Date 11-01-2005 23:41

What brand truck manufacturer builds frames from aluminum?
I'd like to see one.
It makes me feel real good knowing that someone has figured how to get around the fatigue cracking that has, up untill now, always plagued aluminum

By trevwelder Date 11-02-2005 01:07

I welded aluminum on a Kenworth and Peterbuilt. I am looking at a early 1980s Mack that I might have to switch beds on, it also has a aluminum frame. I have made a 1994 Peterbuilt into a corn truck that had aluminum frame, I ran a steel frame insert that was bolted on.

By leon phelps (**)

Date 11-05-2005 03:14

I am sure if they make rims from aluminum and trailers from aluminum that it is done.

If I remember reading a tire manufacturer magazine a long time ago, aluminum will actually hold more weight before bending than steel does.

By OSUtigger (**)

Date 11-05-2005 21:50

Leon,

Just to clarify your statement, there are several types of aluminum that have higher yield strengths than steels, this is true (7075 and 2024 are some of these, they have higher yield strengths). But this is only at the point of permanent deflection. Aluminum will deflect more at the same load (without permanent deformation) than any steel alloy, and is very very sensitive to fatique cracking. I also have trouble believing that a true semi frame is made of Al, but that does not mean that it does not happen, especially with the weight considerations that the industry must subscribe to. I would definitely be weary of such a thing.

gls

By JTMcC

Date 11-05-2005 22:46

Aluminum frames go way back and were real common for several years. I know Mack was using them as far back as the 70's. Like somebody said, several makes used them. I've worked on several 20 to 30 year old trucks with alu frames holding up just fine.

JTMcC.

By Cat Mechanic (*)

Date 11-06-2005 14:07

I drive a '77 International Transtar with an aluminum frame. Still in good shape. It is very thick (1/2" or 5/8" I'm guessing) compared to steel frames.
Jim