From LSWiki

Aperture: Alloy

Alloy focuses on the capacity of one's lens to be shaped into enduring objects, and more generally the capacity of light to interact with metal. This aperture enhancing one's constructs and ultimately gives one a greater leeway to interact with ferrous materials.

Primary Skill  : metal affinity

• Tier 1  : lesser smithing specialty access, access to the Repair volition
• Tier 2  : major smithing specialty access, access to the Empower and Balance volitions
• Tier 3  : greater smithing specialty access, increased tolerance to ferrous materials