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[W.L. Fuller, Inc.] [Products] [Screwdriver Bits]


Screw Head Types


Socket Head / Allen Head


Order Online
Drill Charts



Square Recess Robertson

Torx w/ Pin

Socket Head w/ Pin


Double End Bits

Steel Types

Commonly Asked Questions:

Are your screwdriver bits milled or forged?   Most of our bits are forged for many reason such as life, performance, prompt delivery and better production.  We do offer some as milled and they are indicated in the catalog as such.

How hard are your screwdriver bits?   Extra Hard: 59-63 HRc,  Medium Hard & Iso-Temp: 52-56 HRc

Why is this important?  Medium Bits are recommended for driving standard (soft) screws and for impact useExtra Hard Bits are for driving heat-treated or case hardened screws, such as sheet metal or self-tapping and self-drilling screws.  Iso-Temp Screwdriver Bits are in the Medium Hard Range and also provide additional flex as needed in some applications such as Torq-Set or Tri-Wing Bits.

How do I determine if my bit failed due to being too hard or soft?   In general soft bits will round while hard bits will shatter. Sometimes trial and error provides the best information.

Do your bits have ribbed tips?   We offer ribbed tips in some of our Screwdriver Bit configurations and still offer bits without for those jobs where you may not need or want that tight of a fit.  Ribs reduce slippage (cam-out) and can be a real advantage when desired.

Parts and Types of Screwdriver Bits:


Insert Bits are compact bits that are economical, change over quickly,  require less storage space and require a bit holder.  They are 1” overall length with 1/4”, 3/16” and 5/16” hex shanks.


Power Bits fit directly into the power tool for improved concentricity and easier clearance.  They are 1-15/16” to 6” or longer overall length with 1/4” and 5/16” hex shanks.