Stamped Brake Drum Picture?

[dmengel]

Does anyone have pictures of the stamped and cast brake drums that show the differences? I think all I’m seeing online are cast ones and I’m not sure what I have on my car.

[Joe K]

Stamped brake drums are about 95 percent of brake drums out there. Characterized by a fairly thin section and a "rolled" edge.

Cast drums tend a bit thicker, have an edge that is "square & machined" and can be characterized by a "sandcast" look of the external drum surface (i.e. the casting sand leaves its own imprint in the solidified metal - this on older cast drums.)

Here are pix of original drums and backing plates removed as a unit. Note the rolled edges of both drum and backing plate which nearly "fit together."




Here are cast drums. Note the thicker section and the squared off edge.





Joe K

[fast150]

I have noticed that the original steel drums do not have the large chamfer around the lug bolt holes. The new cast drums have that chamfer as pictured in Joe K's post above. I think that chamfer made swedging the lugs more difficult. If the drum material came up near the top of the step on the lug bolt, one would not have to swell the lug diameter so deep. With the large chamfer there, it seems to take more pressure, and the swedging tool has to go down into the chamfer further. It takes great care not to crack the casting between the lug hole and the large center hole. Just my observation.

[dmengel]

Perfect! Thanks! My worries are confirmed that mine are stamped 😕

[Joe K]

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"Reinforcing bands" are a possible partial remedy. IIRC most parts houses have these which can be heated/pressed on over an existing drum.

One earlier respondent of this board made his own reinforcing bands out of Pinto engine flywheels.

Joe K