DIN 74-Af3 ? help please

I have a print from Germany(I think). It has a couple callouts I cant figure out and my google-fu is failing me

DIN 74-Bf4
DIN 74-Af3

As far as I can figure out DIN 74 means it is a 90 countersink hole and thats what the print looks like it is showing, what I cant find is what the Bf4 and Af3 mean?

I have an ISO hole chart and thought thats what the f3 and f4 were maybe referencing, but I dont see either on the chart.

thanks for any help

Check here:
Sektion Physik, Zentralwerkstatt, template

A and B refer to the Din-standard for the fastener
f is for "fine" (as opposed to "medium")
3 and 4? no idea.

Benta.

Thanks Benta.

DIN 74 Bf4
90deg. c'sink for countersunk socket head screw DIN 7991
Form "B"
Execution: fine
For dia. 4mm
Hole dia 4.3mm H12
Top dia 8.3mm H12
Depth of c'sink approx.2.4mm
Straight from the top surface before the 90 deg starts 8.3 H12 mm dia, 0.3mm+0.1 deep.

DIN 74 Af3
90deg. c'sink for countersunk head screw
Form "A"
Execution: fine
For dia 3mm.
Hole dia: 3.2mm H12
Top dia.: 6mm H12
Depth of c'sink: approx. 1.7mm
Straight from the top surface before the 90 deg starts 6 H12 mm dia 0.25mm+0.1 deep

Note: Form"B" is for 90 deg. c'sunk socket head screws as per DIN 7991.

Form"A" is for 90 deg. c'sunk screws as per DIN 963, 965.
Also for "raised c'sunk head srews" as per DIN 964,966
Also for c'sunk screws as per DIN 7513,7516, 7500
C'sunk wood screws as per DIN 97 and 7997.
Raised head c'sunk wood screws as per DIN 96 and 7995.

It would be a good idea if you could find the exact DIN number of the screw
they plan to use for Form "A" and for Form "B".

Thanks Juergenwt, that will do it.

Halo morning...
can u tell me DIN 47 kf6 ? help please

Are you sure about your numbers?
Ra-Rz Conversion DIN 47

how about dimension ? As I know got dimension .. the pin hole one