VCCA Home Forums TECHNICAL - 1945 AND NEWER 1946-1948 Brake drum maximum size

I would like to know the maximum internal diameter (or the minimum wall thickness) of the front brake drums before they get used as fishing sinkers. I have checked my manual, but i can,t find any specs for these.

Many automotive service manuals will state a max oversize. Some machine shops I have used would consider 1/8 inch (0.125) minimum drum thickness after turning to eliminate bell mouth profile. I have generally accepted that thinking but reality is that the thinner the drum the more quickly brake fade comes on.
A second consideration is whether your machine shop has a lining arcing device so that full lining contact is possible. If that's not done you get reduced brake affect and squealing occurs as the partial contact area becomes glazed from overheating. I have had that happen More often now that my machine shop no longer will arc linings. Living in the backwoods with few alternatives I now just pull off the drum if the squeal bugs me and use my 4 inch hand grinder to reduce the high spots. That's not smart but I rarely drive my old beasts over 45 mph on our backroads. Dan

i was told that a quick visual is when the 45 degree chamfer cut on the flat face to innner diameter is no longer there.

If it's been turned before...machine shop won't add the 45 degree angle...But...I don't know how "deep" that original 45 is on new drums...I've never seen it on mine...True, most shops won't "arc" shoes any longer...Call around and find one that still has an arcing machine...There far and few between...True you can remove the high spots...Generally in the center of the shoe...If you have a good belt sander, that helps....Sand a little, hold the shoe to the drum and see if you can get it close...

sorry for being vague, the angled cut leading into the inner diameter of the drum is from the factory. if the drum has been turned to many times where the angle is no longer visible indicates it is no longer good for use. keep in mine that the angled cut is just a quick visual, i'm sure there is an actual dimension in a spec somewhere. i do not know what that dimension is that indicates a bad drum.

Just ran a quick check on the "net", and one site says maximum diameter shouldn't be more than 11.090 inch's...Says it is stamped on the drum...I've never noticed it stamped on the drum myself...

The numbers were not stamped on the drum til some where in the '60' or '70's.
The max years ago was around .080" to .100"
Say in 1950 very fewdrums were turned. Most people had the brakes relined before the rivents contacted the drums. Our shop was large and well equipped and we didn't even have a brake lathe til about 1953. Prior to that we sent the drums out for turning.

Took my scored drum to a brake shop here and I was told that they won't machine more than .060 oversized! Luckily I dug up a rear which was only .010 oversize, and is smooth and won't need machining !
It looks like it will fit the front hub after I have ground the rivets off, can anyone confirm this?,