Sales Systems Ltd. - Square Nuts

Unification. Bold type indicates products unified dimensionally with British and Canadian standards.
Tops of Nuts. Tops of nuts shall be flat and chamfered or washer crowned. Diameter of the chamfer circle shall be equal to the maximum width across flats within a tolerance of minus 15 percent. The surface of the chamfer may be slightly convex or rounded.
Width Across Flats. Maximum width across flats shall not be exceeded. No transverse section through the nut between 25 and 75 percent of the actual nut thickness as measured from the bearing surface shall be less than the minimum width across flats.
Bearing Surface. Bearing surface shall be perpendicular to the axis of the threaded hole within a tolerance of 3 deg for 1 in. nominal size nuts or smaller, and 2 deg for nuts larger than 1 in.
True Position of Tapped Hole. The axis of tapped hole shall be located at true position with respect to the axis of nut body within a tolerance zone having a diameter equivalent to 10 percent of the maximum width across flats, regardless of feature size.
Threads. Threads shall be Unified coarse thread series (UNC series), Class 2B, in accordance with ASME B1.1
Material. Unless otherwise specified, chemical and mechanical properties of steel nuts shall conform with Grade A of ASTM A563. Nuts of other materials such as corrosion resistant (stainless) steel, brass, bronze and aluminum alloys shall have properties as agreed upon between the manufacturer and purchaser. The properties for nuts of several grades of corrosion resistant steel alloys are covered in ASTM F594 and of several nonferrous materials in ASTM F467.
Nominal Size. Where specifying nominal size in decimals, zeros preceding the decimal and in the fourth decimal place shall be omitted.

Unit of Measure

Items	SN02500XXX Square Nut, 1/4" Nominal Dia.	SN03125XXX Square Nut, 5/16" Nominal Dia.	SN03750XXX Square Nut, 3/8" Nominal Dia.	SN04375XXX Square Nut, 7/16" Nominal Dia.	SN05000XXX Square Nut, 1/2" Nominal Dia.
Manufacturer	N/A Industrial Fasteners Institute
Product	N/A Nuts
Codes and Standards	N/A ASME/ANSI B18.2.2 1987 (R 1999)
Unit of Measure	N/A English
Nominal Size or Basic Major Dia. of Thread	N/A 1/4 in	N/A 5/16 in	N/A 3/8 in	N/A 7/16 in	N/A 1/2 in
Nominal Size or Basic Major Dia. of Thread (Decimal)	N/A 0.2500 in	N/A 0.3125 in	N/A 0.3750 in	N/A 0.4375 in	N/A 0.5000 in
Basic Width Across Flats (F)	N/A 7/16 in	N/A 9/16 in	N/A 5/8 in	N/A 3/4 in	N/A 13/16 in
Max. Width Across Flats (F)	N/A 0.438 in	N/A 0.562 in	N/A 0.625 in	N/A 0.750 in	N/A 0.812 in
Min. Width Across Flats (F)	N/A 0.425 in	N/A 0.547 in	N/A 0.606 in	N/A 0.728 in	N/A 0.788 in
Max. Width Across Corners (G)	N/A 0.619 in	N/A 0.795 in	N/A 0.884 in	N/A 1.061 in	N/A 1.149 in
Min. Width Across Corners (G)	N/A 0.554 in	N/A 0.721 in	N/A 0.802 in	N/A 0.970 in	N/A 1.052 in
Basic Thickness (H)	N/A 7/32 in	N/A 17/64 in	N/A 21/64 in	N/A 3/8 in	N/A 7/16 in
Max. Thickness (H)	N/A 0.235 in	N/A 0.283 in	N/A 0.346 in	N/A 0.394 in	N/A 0.458 in
Min. Thickness (H)	N/A 0.203 in	N/A 0.249 in	N/A 0.310 in	N/A 0.356 in	N/A 0.418 in