Slotted Hex Nut Size Dimensional Data Table Chart per. ASME B18.2.2. All dimensional data given in inches.
Heavy Hex Slotted Nut
Hex Thick Slotted Nut
(a) 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 4% of the maximum width across flats, regardless of feature size.
(b) Countersink. Tapped hole shall be countersunk on the bearing face or faces. The maximum
countersink diameter shall be the thread basic (nominal) major diameter plus
0.030 in. for 3/8 in. nominal sire nuts and smaller, and 1 .O8 times the basic major
diameter for nuts larger than 3/8 in. No part of the threaded portion shall project beyond
the bearing surface.
(c) Threads. Threads shall be unified coarse, fine, or 8 thread series (UNC, UNF or 8 UN
series), Class 28.
(d) Material. Unless otherwise specified, chemical and mechanical properties of steel
nuts shall conform with Grade A of ASTM A 563, Carbon and Alloy Steel Nuts; or
Grade 2 of SAE J995, Mechanical and Material Requirements for Steel Nuts. 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 F 594, and of several nonferrous materials in ASTM F 467.
(1) Width Across Flats. Maximum width across flats shall not be exceeded (see exception
in General Data). No transverse section through the nut between 25% and 75%
of the actual nut thickness as measured from the bearing surface shall be less than
the minimum width across flats. For milled-from-bar nuts, see statement in General
Data pertaining to the nominal bar size to be used.
(2) Corner Fill. A rounding or lack of fill at junction of hex corners with chamfer shall be
permissible provided the width across corners is within specified limits at and beyond
a distance equal to 17.5% of the basic thread diameter from the chamfered faces.
(3) Tops and Bearing Surfaces of Nuts. Nuts in sizes in. nominal size and smaller shall
be double chamfered. Larger sire nuts shall be double chamfered or have washer
faced bearing surface and chamfered top.
The diameter of chamfer circle on double chamfered nuts and diameter of washer
face shall be within the limits of the maximum width across flats and 95% of the minimum
width across flats.
The tops of washer faced nuts shall be flat and the diameter of chamfer circle shall
be equal to the maximum width across flats within a tolerance of - 15%. The length
of chamfer at hex corners shall be from 5% to 15% of the basic thread diameter. The
surface of chamfer may be slightly convex or rounded.
Bearing surfaces shall be flat and perpendicular to the axis of the threaded hole
within the FIM limits specified for the respective strength level.