AN Hardware

AN Bolt Characteristics

• Hex head • Mild steel or stainless steel

– Cadmium plated for mild steel

• National Fine pitch • Rolled threads • Class 3 fit

AN Bolt Characteristics

• Classes of fit (allowance or distance between bolt diameter and hole diameter) – Class 1 – extra loose – Class 2 – loose (Home Depot hardware) – Class 3 – will drop in hole; no side play

• ~ .003” between bolt and hole diameters

AN Bolt Characteristics

– Class 4 – Close tolerance • Palm press to fit • ~.001” between bolt and hole diameters

– Class 5 – Interference • Bolt is slightly larger than the hole

Designation for Bolts

AN 4 – 7A AN Code

Diameter in 1/16”

Type of Material

Length in 1/8” (base 8)

Absence of Hole in Shank

AN4H7 Hole in Head

AN4C7 CRES AN4D7 Aluminum

AN4HC7 Hole in Head / CRES

AN4-7 Steel

Diameter designation: AN3 through AN20

Designation for Nuts

AN 315 – 4 28 AN Code

Type of Nut

Type of Material

Diameter in Screw Size or

Fraction

Thread Pitch

Designation for Washers

AN 960 – 416 AN Code

Type of Washer

Type of Material

Diameter in Screw Size or

Fraction

Designation for Cotter Pins

AN 380-4-3 AN Code

Type of Fastener and

Material

Diameter in 1/32”

Length in 1/4”

Designation for Screws

AN 520 –416-8 AN Code

Type of Screw and Thread Pitch

Diameter in Screw Size or Fraction

Length in 1/16”

500 NC 501 NF 502 NF 503 NC 505 NC 510 NF 515 NC 520 NF

For type codes that include the pitch with the

head style

Designation for Screws

AN 509 –624-8 AN Code

Type of Screw Diameter in Screw Size or Fraction

Thread Pitch

Length in 1/16”

507 509 525 526

For type codes that do not include the pitch with the head style

Designation for Rivets

AN 470 AD 3-4 AN Code

Type of Rivet

Type of Material

Diameter in 1/32”

Length in 1/16”

Designation for Clevis Bolts

AN 24 – 7A AN Code

Diameter in 1/16” Length in 1/16”

Absence of Hole in Shank

Diameter designation: AN21 through AN36 (#6 through 1”)

Designation for Clevis Pins

AN 394 – 17 AN Code

Diameter in 1/16”

Effective Length in odd 1/32”

Diameter designation: AN392 through AN406 (1/8” through 1”)

AN Code for Fluid Fittings

AN818-6D Type of Fitting

Diameter of Fitting

Type of Material*

*Material: No Letter Plain Steel “D” Aluminum “C” Corrosion Resistant Steel (CRES)