Without exit....

[Fernando Mendes]

A bad trying days...

[Dave72dt]

3/8" x 24 Almost all the body threads use the finer thread.

[Fernando Mendes]

Dave72dt,this is the original pic of mine B3-B right door with the broken bolts.

[Fernando Mendes]

I drilled the hole with a 9 mm drill.When I put the 3/8"=9,525mm bolt it became with a great clearance.Then I had to put a 10mm bolt.

[Dave72dt]

A 3/8 " bolt would normally been drill with a 5/16" bit here in the U.S. or in your case a 8mm bit. I don't know what kind of access you have to U.S. threaded bolts but we measure bolts differently than metric. Here we use threads /inch instead of pitch. A 3/8" x 24 bolt doesn't transfer over to anything metric just as a 10 x 1.5 x 20 won't transfer to anything American made.

[wendleburger]

All my door hinge bolts broke off when I disassembled my '49. I replaced them with 10mm 10.9 grade socket head cap screws and drilled and tapped the backing plates to suit.

The stock bolts don't seem to be any sort of high tensile grade? The heads broke off mine as though they were made of chocolate.

[Dave72dt]

The bolt heads in Fernando's picture don't appear to have any hash marks on them so if the current hardness indicators were in place back then, it would indicate Grade 2 bolts were used, sometimes called butter bolts. A 10.9 might be overkill but we use what we can find. Over here it's hard to find mm socket heads in anything but 10.9.

[Fernando Mendes]

Dave72dt,see the table.It is very practice and useble.Thanks.

[Fernando Mendes]

Yes Dave72dt,like you wrote"a 3/8 " bolt would normally been drill with a 5/16" bit here in the U.S. or in your case a 8mm bit".

5/16=7,938mm,almost 8mm.Thanks.

[Fernando Mendes]

Now I did all perfectly,with more experience,it became very very good.Began with a 4mm drill,after a 6,5mm,until a 8mm(last).After passed the two "machos" and put a new 3/8"x16G bolt.I prefered to put a 16G,not 24G which is the original thread.