FLAT HEAD WOOD SCREW SIZES

Flat head wood screw sizes and dimensions are shown in the following charts according to ANSI B18.6.1-1981 standard for slotted, Phillips, Frearson and Pozidriv drives.

The flat head (also referred to as "flat countersunk head") is a type of wood screw and shall have a flat top surface and a bearing surface with a conical head angle of approximately 82 deg.

The designation of flat head wood screws shall be in following format: Nominal size; product name, including head style and driving provision; material; and finish. Ex: 8 x 7/8 Slotted Flat Countersunk Head Wood Screw, Steel

- Standard lengths of wood screws are given below.

Nominal Screw Length Nominal Length Increment Tolerance on Length
Plus Minus
Up to 5/8 in., incl 1/8 0 0.03
Over 5/8 to 1 in., incl 1/8 0 0.05
Over 1 to 1 1/2 in., incl 1/4 0 0.05
Over 1 1/2 to 2 3/4 in., incl 1/4 0 0.06
Over 2 3/4 in 1/2 0 0.09


Calculator:

INPUT PARAMETERS
Screw Size Number

 


Dimensions of Slotted Flat Countersunk Head Wood Screws
Dimensions of Slotted Flat Countersunk Head Wood Screws
Nominal
Size
Head
Diameter
Head
Height
Slot
Width
Slot
Depth
Fillet
Radius
Number Decimal Amax Amin Href Jmax Jmin Tmax Tmin Rmax
--- --- --- --- --- --- --- --- --- ---
Dimensions of Phillips (Type I Cross) Recessed Flat Countersunk Head Wood Screws
Dimensions of Phillips (Type I Cross) Recessed Flat Countersunk Head Wood Screws
Nominal
Size
Head
Diameter
Head
Height
Recess
Diameter
Recess
Depth
Recess Width Driver Size Recess Penetration Gaging Depth Fillet
Radius
Number Decimal Amax Amin Href Mmax Mmin Tmax Tmin Nmin Max Min Rmax
--- --- --- --- --- --- --- --- --- --- --- --- --- ---
Dimensions of Pozidriv (Type IA Cross) Recessed Flat Countersunk Head Wood Screws
Dimensions of Pozidriv (Type IA Cross) Recessed Flat Countersunk Head Wood
Nominal
Size
Head
Diameter
Head
Height
Recess
Diameter
Recess
Depth
Recess Width Driver Size Recess Penetration Gaging Depth Fillet
Radius
Number Decimal Amax Amin Href Mmax Mmin Tmax Tmin Nmin Max Min Rmax
--- --- --- --- --- --- --- --- --- --- --- --- --- ---
Dimensions of Frearson (Type II Cross Recessed) Flat Countersunk Head Wood Screws
Dimensions of Frearson (Type II Cross Recessed) Flat Countersunk Head Wood Screws
Nominal
Size
Head
Diameter
Head
Height
Recess
Diameter
Recess
Depth
Recess Width Driver Size Recess Penetration Gaging Depth Fillet
Radius
Number Decimal Amax Amin Href Mmax Mmin Tmax Tmin Nmin Max Min Rmax
--- --- --- --- --- --- --- --- --- --- --- --- --- ---




Supplements:



Link Usage
Wood Screw Sizes Wood screw sizes and thread dimensions according to ANSI B18.6.1-1981 standard.

Reference:
  • ANSI B18.6.1 - 1981, Wood Screws (INCH SERIES)