IFI Announces New Standard for Fasteners

The Industrial Fascination Association (IFI) announced a new IFI standard, IFI-171, the screw size is 1-5/8-5-1/2, and 1-7/8 UNS for bolts, studs and nuts in steel construction industry. The new standard specifies that the coarse threads of 1-5/8-5-1/2 and 1-7/8-5 are specified. These two sizes are usually used in the steel construction industry.
IFI standards are formulated by industry experts that are voluntarily formulated by members of IFI members and industry interests. Many of these experts have also participated in the writing of the IFI fastener standard manual, which brings together nearly 100 standards from ASTM, ASME, SAE, and IFI.