Looking for soldering iron with a narrow shaft

[eeguy]

Hello, I have a Weller soldering iron. Can't find the specs but it has a red triangular shape at the front like the SP40NKUS 40. The problem with it is that when I used it with a heat-set insert tip, sometimes the short insert tip and thick shaft (about 10mm in diameter) of the soldering iron caused the iron's shaft to touch or almost-touch the nearby plastic and melt the plastic by accident. Any other good product recommendations? I guess I need a soldering iron with shaft about 5mm in diameter or heat-set insert tip with longer tip.

[Jeroen3]

Related:
https://www.eevblog.com/forum/manufacture/where-can-i-buy-a-jbc-tip-for-installing-heat-set-inserts/

https://www.jbctools.com/cartridges-category-4-design-HeatStacking-menu-4.html

[benj38]

Standard Metcal soldering tips have quite a long shaft with a diameter of around 4.8mm

[Benta]

Antex irons are very slender.
Example:
https://www.antex.co.uk/store/p/m12-w9wdk

[benj38]

Antex irons are very slender.
Example:
https://www.antex.co.uk/store/p/m12-w9wdk

The Antex tips I have are around 6.5mm to 7mm in diameter.

[eeguy]

I used a thin tip for my Hakko FX-601. Although it solved the problem mention in the original post, it created another problem. Threaded inserts were not able to merge well with the plastic PLA. When screwing, the inserts came out.

[JustMeHere]

Show what you are soldering.  You can try some alternative approaches such as hot air, hot plate, the iron from the other side.