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

Flat head wood screw sizes and dimensions:

INPUT PARAMETERS
Screw Size Number

 


Dimensions of Slotted Flat Countersunk Head Wood Screws
Dimensions of Slotted Flat Countersunk Head Wood Screws
Parameter Value
Nominal Size Number ---
Decimal ---
Head Diameter Amax ---
Amin ---
Head Height Href ---
Slot Width Jmax ---
Jmin ---
Slot Depth Tmax ---
Tmin ---
Fillet Radius 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 Number ---
Decimal ---
Head Diameter Amax ---
Amin ---
Head Height Href ---
Recess Diameter Mmax ---
Mmin ---
Recess Depth Tmax ---
Tmin ---
Recess Width Nmin ---
Driver Size --- ---
Recess Penetration Gaging Depth Max ---
Min ---
Fillet Radius 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 Number ---
Decimal ---
Head Diameter Amax ---
Amin ---
Head Height Href ---
Recess Diameter Mmax ---
Mmin ---
Recess Depth Tmax ---
Tmin ---
Recess Width Nmin ---
Driver Size --- ---
Recess Penetration Gaging Depth Max ---
Min ---
Fillet Radius 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 Number ---
Decimal ---
Head Diameter Amax ---
Amin ---
Head Height Href ---
Recess Diameter Mmax ---
Mmin ---
Recess Depth Tmax ---
Tmin ---
Recess Width Nmin ---
Driver Size --- ---
Recess Penetration Gaging Depth Max ---
Min ---
Fillet Radius 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)