Summoning sickness — the rule that prevents a permanent from attacking or using tap/untap abilities — applies only to creatures. This is defined in CR 302.6: a creature cannot attack or use a tap or untap ability in its activation cost unless it has been under your control since the beginning of your most recent turn.
Non-creature artifacts are not subject to this restriction at all. CR 302.6 specifically limits the rule to creatures. So if an artifact enters the battlefield and is not a creature, you may activate its tap abilities immediately, even on the very turn it arrived.
This is true even if the artifact has a tap symbol in its cost. The summoning sickness rule cares about whether the permanent is a creature at the time you want to activate the ability, not whether the ability uses the tap symbol.
Concrete example: You play Sol Ring (an artifact, not a creature) on your first turn. You can immediately tap it for two colorless mana the same turn it entered, because Sol Ring is never a creature and summoning sickness does not apply to it.
If somehow an artifact were also a creature (an artifact creature like Ornithopter), summoning sickness would apply, and you could not use its tap abilities that turn unless it has haste (CR 702.10).
Unofficial fan resource — not affiliated with or endorsed by Wizards of the Coast. Answers are AI-generated estimates grounded in the Comprehensive Rules and are not a substitute for an official judge. Verify anything match-critical.