Master's Inscription of the Axe

This is one of the generic physical damage profession "bonuses" which gives around 64 additional attack power over the standard enchant.

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• Inscription: Shoulder enchant Master's Inscription of the Axe - grants an additional 64 attack power.
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• Enchanting: Enchant Rings (Assaultx2) Which gives 64 Attack power.
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• Leatherworking: Fur Lining - Which gives 64 additional attack power over the standard bracer enchant.
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• Blacksmithing: Socket Bracer and Socket Gloves which can allow you to socket 2 additional Bright Scarlet Ruby for 64 attack power.
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• JewelCrafting: you can make 3 unique gems Bright Dragon's Eye which gives you 66 additional Attack power over the conventional ones.
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• Tailoring: Cloak Enchant - Swordguard Embroidery - this comes out to around 58attack power according to EJ but how much of an upgrade this is is another matter.
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The non-inscriber version of this has only 40 attack power, Greater Inscription of the Axe, not 64 AP. I think you may have been thinking that this one is 64 AP more then the one usable by everyone. 64 extra permanent AP is quite a decent chunk, even for WotLK standards.

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• Alchemy: Mixology which increases the effect of Flask of Endless Rage by 64 attack power, as well as doubling the duration.
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• Herbalism: Fire Leaf used once a minute results with an average of 66.7 attack power, unless you're a Warrior or Death Knight that caught the 30 second armor calculation at the wrong time. Then it's probably an attack power decrease.
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Sadly, the use effect on Fire Leaf has been removed in the latest 3.0.8 PTR push.