Split/crack around new drums?

[icetech]

So, bought new drums so i can get my rear end back together (Waiting on 1 seal!) Anyway.. the drums showed up and both have this split in them, i have seen pics of other brands with the same thing.. is this just a processing thing? I haven't worked on any drum brakes in over 20 years but i don't recall seeing this before..
P.S. these are raybestos.. (The line where the hub meets the outer ring..

 

[PurpleBeeper]

what split?

 

[Cranky]

Seen that lots of times and never had a problem with them.

 

[Cranky]

what split?

Look at the 10 and 2 o'clock areas and you'll see what he's talking about.

 

[icetech]

Like on the left there.. i'm sure it's just the manufacturing.. but just seems odd to me is all, rather check and be sure that's normal

 

[zyzzyx]

the hub is steel, the drum is cast iron. Two piece, different materials. Probably the way it's manufactured.
Raybestos drums I believe are made of "Chinesium".

 

[Cranky]

the hub is steel, the drum is cast iron. Two piece, different materials. Probably the way it's manufactured.
Raybestos drums I believe are made of "Chinesium".

What isn't Shinese these days

 

[icetech]

the hub is steel, the drum is cast iron. Two piece, different materials. Probably the way it's manufactured.
Raybestos drums I believe are made of "Chinesium".

But.. the 2 materials would explain it.. I know it was a silly question but i am paranoid bout brakes.

 

[69Bee]

Those are called "Composite" drums. They are a two-piece construction, cast iron outer molded onto a steel hub. What you see is normal.

edit: zyzzyx beat me to it...

 

[Cranky]

A bit of info here..... Brake-Drum Metallurgy

 

[RJRENTON]

But.. the 2 materials would explain it.. I know it was a silly question but i am paranoid bout brakes.

Its likely due to the shrinkage rate of the iron casting around the steel flange insert. Iron has many different alloys, and all have different shrinkage rates....possibly cured by a annealing process (controlled cooling to prevent shrinkage cracking as shown). The unknown quantity is the grade or composition of the iron alloy...knowing the source (Chinese) of the iron, it could be old coat hangers or engine blocks or scrap Yugo's or ???? and the casting process....via a mold or centrifugally cast..... judt my opinion of course
BOB RENTON

 

[Darter6]

. i'm sure it's just the manufacturing..

Yes, as stated bonding cast and steel. Common and not a problem.

 

[icetech]

Thanks guys, i had no idea they were made of 2 materials... now i know