Panther Builders Manual

AN3-AN20 Most common bolts in aviation, usually cad plated steel.

These bolts have a tolerance of 0.003” and are fine thread.

The materials can be: Steel (-), Aluminum (DD),  or Stainless (C)

Size designations are 3 through 20, and are fine threads; diameter is listed in 1/16” increments.  (-3 is 3/16”, -4 is ¼”)

Part number breakdown: First number is the diameter in 1/16”, next locations are material (-,DD,C), then H or blank for drilled head, then Length, and finally blank for drilled shank or A for undrilled shank

Length of bolt can be determined by the following for AN3 and 4:

If single digit the overall length of the bolt in 1/8” increments + 1/32”,

(Example:  AN3-4A is 4/8” + 1/32” or .531” long and 3/16” diameter undrilled)

If a double digit, first digit is the number of inches, second digit is number of 1/8” increments + 1/32”

(Example: AN3-14A is 1” + 4/8”+ 1/32” or 1.531” long and 3/16” diameter undrilled)

Options:        ‘-‘ in part number is cad plated steel

         ‘DD’ in part number is Aluminum

         ‘C’ in part number is Stainless Steel

‘H’ in part number is drilled head

         ‘A’ in part number is solid shank (un-drilled)

Common sizes, grips and lengths

Current spec: NASM3 thru NASM20

NAS6603-NAS6620 Close tolerance bolts, cad plated steel.

These bolts have a tolerance of 0.001” and are fine thread.  Typically used in high strength shear applications where a tight fit in the hole is required for strength (example: Wing spars).  Threads are short, so typically MS21042 nut is used instead of the MS21044 or AN365 full height nuts.

Size designations are 3 through 20, and are fine threads; diameter is listed in 1/16” increments.  (-3 is 3/16”, -4 is ¼”)

Dash number of bolt is grip length in 1/16” increments

Options:        ‘H’ after basic number for drilled head

         ‘D’ after basic is drilled threads

         ‘X’ or ‘Y’ after grip dash number oversize repair bolts

Current spec: NAS6603-NAS6620

Common sizes, grips and lengths

 

 

NAS7400-NAS7416 Close tolerance bolts 100 degree countersunk head, cad plated steel.

These bolts have a tolerance of 0.001” and are fine thread.  Typically used in high strength shear applications where a tight fit in the hole is required for strength (example: Wing spars).  Threads are short, so typically MS21042 nut is used instead of the MS21044 or AN365 full height nuts.

Size designations are 0 through 16, and are fine threads;

diameter is listed in 1/16” increments for NAS7403 or larger.  (-3 is 3/16”, -4 is ¼”)

NAS7400 is .1120-40 (#4 screw) thread, NAS7401 is .1380-32 (#6 screw) thread, NAS7402 is .1640-32 (#8 screw) thread

Dash number of bolt is grip length in 1/16” increments

Options:        ‘D’ after basic is drilled threads

         

Current spec: NAS7403-NAS7416

Common sizes, grips and lengths