AATB federal item identification guide code

AATB is the Federation Item Identification Guide code for the “width between flats” specification.

Definition	A measurement between he parallel flat surfaces of either an internal, or external he'd or drive style of a threaded fastener.
Instructions	Enter the applicable Reply Codes from Table 1 below, followed by the numeric value. A default of “nominal” will be used if no leading Reply Code is provided.
Note	The numeric value must be entered in millimetres.

Table 1 Code Defintion A Nominal B Minimum C Maximum

Examples

 

Stand-alone formats

This    {{AATB-FIIG-code/designation | A5.0 }}   renders as    5.0 mm (0.20 in) nominal

This    {{AATB-FIIG-code/designation | B10 }}   renders as    10 mm (0.39 in) min.

This    {{AATB-FIIG-code/designation | C7.75 }}   renders as    7.75 mm (0.305 in) max.

This    {{AATB-FIIG-code/designation | 10.5 }}   renders as    10.5 mm (0.41 in) nominal

This    {{AATB-FIIG-code/designation | 2.5 }}   renders as    2.5 mm (0.098 in) nominal

 

In “Technical Characteristics” table formats

This    {{specification-table row | AATB | A5.0 }}   and;

This    {{specification-table row | AATB | B10 }}   and;

This    {{specification-table row | AATB | C7.75 }}   and;

This    {{specification-table row | AATB | 10.5 }}   and;

This    {{specification-table row | AATB | 2.5 }}   renders as:

Code	Specification	Designation
AATB	Width between flats	5.0 mm (0.20 in) nominal
AATB	Width between flats	10 mm (0.39 in) min.
AATB	Width between flats	7.75 mm (0.305 in) max.
AATB	Width between flats	10.5 mm (0.41 in) nominal
AATB	Width between flats	2.5 mm (0.098 in) nominal