Soldering lugs with hole

[e44-72]

Hello

I want to know what the best way is to solder a wire onto a lug through the lug hole
Is it better to put the soldering iron the opposite side to where the solder is applied or the same side of the lug as where the solder is applied.

Diagrams are attached to explain what I mean

Thank you for any help.

 

[JimB]

The lug will probably have the larger thermal mass than the wire, so having the tip of the iron in contact with the lug would be the best option.
Whether the iron is on the same side as the solder or the opposite side, I would put the iron and solder on the same side, then when the solder melts it makes a good thermal contact between the iron and the lug and the wire.

The important things are:
1 all the components are up to the correct temperature
2 the solder makes good contact and "wets" all the components
3 there is the correct amount of solder on the joint (not too much, not too little).

JimB

 

[e44-72]

Thank you Jim B for your advice.

 

[Dean Huster]

Most of us were taught to run the wire through the hole in the lug, then give it a 180° or 360° wrap around the lug. This is nonsense. Put the wire(s) through the hole and then solder. If you think that industry would not cotton to such thing, consider Tektronix, Inc. Their standard for the venerable 500-series was just that: poke the wire(s) through the hole and solder.

(1) It makes for a lot easier desoldering during repair, especially if you need to remove only one wire;
(2) There's less thermal mass to solder since there's less wire in contact with the lug;
(3) Assembly is faster;
(4) There's really no compromise in conductivity or reliabilty.

I did find a grounding lug on a piece of Hewlett-Packard equipment with the wire wrapped around the lug -- and it had never been solder and the equipment ran fine for years. So, maybe that's one advantage of the wrap it until you're blue in the face: you really don't have to solder.

 

[e44-72]

thank you for your advice.