iFixit Bit Information (A Bit On Bits)

6150 Steel: A specific designation of steel composition given by the AISI. Contains Carbon, Manganese, Phosphorus, Sulfur, Silicon, Chromium, and Vanadium.
- SEE ALSO: Cr‐V Steel https://en.wikipedia.org/wiki/Chromium-vanadium_steel
S2 Steel: A specific designation of steel composition given by the AISI. Harder than 6150, but more brittle.
Cr‐V Steel: A broad category of carbon steel with good machining and hardenability. 6150 is a grade of Cr‐V steel.

Nickel: Currently used on all iFixit Screwdriver Bits. Adds corrosion and wear resistance.
Zinc: Similar properties as Nickel, but more blue in color.
Black Oxide: A rough, black coating applied to screwdriver tips to add mild corrosion resistance and improved grip. The old iFixit screwdrivers had Black Oxide Tips.

Torx: A specialty six‐lobed drive scheme developed and licensed by Acument. Many companies make "Torx Compatible" screwdrivers and bits, which may or may not work just fine. At iFixit, we've got the real deal, and you'll see Torx proudly printed on the side of our screwdriver bits.
Phillips: An old drive style that is now publicly available and governed by ISO8764‐1.
JIS: An old drive style that is now publicly available and governed by JIS B 4633. The only notable difference between JIS and Phillips occurs at size 0 and below. The internal radius of the cruciform is the most notable difference.
Tri‐point: A custom drive style engineered by iFixit to accommodate the three lobed screws in Apple Watches and iPhone 7/7+/etc.
Phillips #0/00/000: All slight modifications on Phillips 0. Technically, all three are interchangeable and it's only the outer diameter of the bit that changes. However, the advantage of PH000 and PH00 over PH0 is better clearance and accessibility. This sizing scheme does not translate to Tri‐point, for which Y000/Y00/Y0 are completely different drive sizes and are not interchangeable.