金屬工資料手冊（家庭機械師）

The 31 categories make it stupidly easy to flip straight to whatever spec I need mid-project, and it's saved me more than once when designing a jig. Honestly, this thing lives on my bench now, dog-eared and all.

Finally a reference that pulls together all the trig formulas and thread data I need without flipping through three different books. The 31 categories are organized well enough that I found the gear tooth dimensions section in seconds.

The table of tap and drill sizes in the data book saved me from digging through drawers on my last lathe project. It’s laid out clearly enough that I can find cross-references on heat treatment without flipping back and forth. This is the kind of workshop reference that earns its spot on the bench.