Late game Steel

[SurvivoroftheNoobs]

Mountains are mostly stripped clean and haven't seen traders selling any. So what does everyone do for the mass quanity of steel needed for late-end game survival? Because its to a point that a single raid can cost hundreds of steel or in the case of mechanoids over a thousand.

[Grishnerf]

Research deep mining/Drilling.
even on flat maps there are enough ressources Underground to mine.

[mumblemumble]

deep drills, smelting items, trading... there are ways, the biggest thing is to anticipate needs. If you need a trader NOW, it means you didn't plan a WEEK ago... also, calling traders can be worth it IF you buy in bulk.

300 silver might seem a bit steep, but if you have lots to buy and  sell,  it can even out alright. Just have enough left over to clear them out for what you need.

[Blastoderm]

Use mods for infinite mining, like Mininc.inc. It's infinite mining but in low amounts.

[Andy_Dandy]

Traders are selling steel (bulk goods traders). You just have to think about it before you desperatly need the steel, and build up a Storage, since you won't get a bulk goods trader visiting you every day of the week.

[Blastoderm]

Bulk goods are rare even with mods that triple their arrival rates. Without mods, they can be regarded as a rare luck, rather than expected. I waited for years(!) for space traders.

[Canute]

You need to be friendly with a faction that can send this kind of trader.

At at late game you should have enough to sell to call every day a caravan, buy the steel and still sell so much to get the caravan's silver.

[Rafe009]

Use mods for infinite mining, like Mininc.inc. It's infinite mining but in low amounts.

Cheating.

As one of the other posters suggested, smelting down raider weapons rather than selling them is a great source for steel. In the early game steel is abundant and silver is not as available so selling weapons for 100 to 300 silver is a good strategy but by mid to late game when you start rolling in silver the a 300 silver economic loss is often a worth 20 steel.

That leads to the 2nd point. If you are swimming in silver and have rooms filled with it it's actually not a bad idea to buy crappy weapons from weapon traders even if it sets you back 300 a pop and smelt those down. Particularly handguns, survival rifles, shivs and knifes.

[Shurp]

Considering how hard steel is to get, and how easy silver is, maybe it would be worthwhile to mod the game to make it possible to build everything out of silver.

Yes, silver turrets

[Blastoderm]

Deep drill mining is still finite, so it's just an bonus to build space ship and get off the planet. For long-standing colonies it's either neverending smelter of knives, which is tedious, boring and unfun