Screw Dimensions Reference Tool

UNF Threads/Inch
Stress Area 
Tap Drill 
UNC Threads/Inch 
Stress Area 
Tap Drill 

Oval Point Full Dog Point Cup & Flat Point

Truss Head

Binder Head

Round Head


Button HEAD

Flat & Oval Head

PAN Head

Socket HEAD


Hex Nut

Thin Hex Nut
(Jam Nut)

Hex Nut

Uss Washer

SAE Washer

Split Lock Washer


Unless otherwise noted, all Screw Data is per ASA B18.6. All Head Dimensions are maximum. Hex Head Bolts from 7/16" through 1" are per ASA B18.2. Hex Nuts from No. 0 through No. 10 are per ASA B18.2, American Standard Machine Screw and Stove Bolt Nuts. Hex Nuts from 1/4" through 1" are per ASA B18.2, Amercan Standard Finished Hexagon Nuts and Finished Hexagon Jam Nuts. Socket and Button Head Cap Screws, Shoulder Screws and setscrew points are per ASA B18.3.