Weller PU-2D Soldering Station

[Skywave]

I would argue that the "all the bits in the range have the same mass" is only true for bits of the same shape.
Alan

Agreed; point taken.

Al.

[Bushbaby]

Thanks Alan and Al,
I have reverted to the No7 and things have stopped melting! The difference between the 2 bits is very noticeable.

Rob

[AlanBeckett]

Excellent!
The advantage of the Weller over 'ordinary' Irons of the time was that while idle it didn't get excessively hot, but when you applied it to a joint and the Bit temperature dropped a tad you got the full 48W. A short fat Bit will make joints on quite big bits of chassis.

Alan

[Skywave]

Just to add something really useful to this thread: bit numbers and running temperature.

Bit # 6 → 600 °F = 315 °C
Bit # 7 → 700 °F = 370 °C
Bit # 8 → 800 °F = 430 °C
Bit # 9 → 900 °F = 482 °C

Al.

[AlanBeckett]

Al,

I don't think I've ever come across a '6'.

Alan