Ironweb Spider Silk

Source
Ironweb Spider Silk is dropped by level 50 through 60 spiders and is used as a component in recipes for several professions.

As an ingredient
This item is used in the following recipes:

Engineering

 * Delicate Arcanite Converter (level 285)
 * Goblin Jumper Cables XL (level 265)

Leatherworking

 * Chromatic Gauntlets (level 300)
 * Corehound Belt (level 300)
 * Dreamscale Breastplate (level 300)
 * Lava Belt (level 300)
 * Molten Belt (level 300)
 * Stormshroud Gloves (level 300)
 * Timbermaw Brawlers (level 300)

Tailoring

 * Argent Boots (level 290)
 * Argent Shoulders (level 300)
 * Big Bag of Enchantment (level 300)
 * Bloodvine Boots (level 300)
 * Bloodvine Leggings (level 300)
 * Bloodvine Vest (level 300))
 * Brightcloth Pants (level 290)
 * Core Felcloth Bag (level 300)
 * Felcloth Bag (level 300)
 * Flarecore Robe (level 300)
 * Gaea's Embrace (level 300)
 * Ghostweave Belt (level 265)
 * Ghostweave Gloves (level 270)
 * Ghostweave Vest (level 275)
 * Mantle of the Timbermaw (level 300)
 * Runecloth Boots (level 280)
 * Runecloth Cloak (level 265)
 * Runecloth Headband (level 295)
 * Runecloth Pants (level 285)
 * Runecloth Robe (level 260)
 * Runecloth Shoulders (level 300)
 * Runecloth Tunic (level 260)
 * Runed Stygian Belt (level 300)
 * Runed Stygian Boots (level 300)
 * Runed Stygian Leggings (level 300)
 * Satchel of Cenarius (level 300)
 * Sylvan Crown (level 300)
 * Sylvan Shoulders (level 300)
 * Sylvan Vest (level 300)
 * Wisdom of the Timbermaw (level 290)

As a quest objective

 * Uniform Supplies