DIN 910 G1 Pipe plug thread relief. Official dimensions needed. 1

[Tmoose]

Most every representation of a DIN G1 ( straight BSPP thread) plug consistently shows a curious thread relief profile between the end of the thread and bolt head flange.

Pictorially it looks like the profile will jam on the top edge of the tapped hole, keeping the plug from seating on the sealing washer, unless a very thick washer is used.

I have found no dimensions to prove or disprove that.

We had some drain plugs made locally, using just the DIN description. They did indeed jam on the hole edge before compressing the copper sealing wssher. The casing is OEM, made in Germany or Japan,
so presumably if some special detail is needed for the tapped hole, it would have been provided.

 

[RolMec]

Hello Tmoose,

this thread relief is governed by standards 3852-1 and -2, in your case (pipe thread) its the -2.
With DIN 910, one needs to distinguish between standard and light executions.
G type plugs require an additional sealing element (sealing ring / washer DIN 7603).
The diameter you seek for a G1A plug is 29.9 mm, whereas the core dia. of the ISO 228-1 G1 thread is 30.291 mm.

Regards


Roland Heilmann
Lpz FRG