IFI-128 is a standard developed through the procedures of Industrial Fasteners Institute. IFI-128 was first published in 1978 and reaffirmed, without technical change, in 1986 and in 2000.
Unit of Measure

Manufacturer

Manufacturer

N/A Industrial Fasteners Institute

Specifications

Product

N/A Nuts

Unit of Measure

N/A English

Nominal Size or Basic Major Dia. of Thread

N/A 2-1/2 in

Nominal Size or Basic Major Dia. of Thread (Decimal)

N/A 2.5000 in

Basic Width Across Flats (F)

N/A 3-7/8 in

Max. Width Across Flats (F)

N/A 3.875 in

Min. Width Across Flats (F)

N/A 3.750 in

Max. Width Across Corners (G)

N/A 4.474 in

Min. Width Across Corners (G)

N/A 4.275 in

Basic Thickness (H)

N/A 7-1/2 in

Max. Thickness (H)

N/A 7.55 in

Min. Thickness (H)

N/A 7.44 in

Codes and Standards

Codes and Standards

N/A IFI-128 2000
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