MIL-DTL-1222 Military Specifications Fasteners

Mil spec MIL-DTL-1222 covers standard studs, hex cap screws, and heavy hex bolts in nominal standard diameters of ¼ inch to 4 inches, nuts in nominal standard diameters of ¼ inch to 3 inches, and socket head cap screws in nominal standard diameters of ¼ inch to 1½ inches for applications where a high degree of reliability is required. MIL-DTL-1222 covers a variety of materials, including: Nickel Alloys, Corrosion Resistant Steels (CRES), Titanium, and Aluminum.

Studs

• Type I – Full body
• Type II – Reduced body
• Type III – Constant strength body
• Type IV - Continuous thread (bolt-stud)

Bolts

• Type II – Heavy hex
• Type III – Heavy hex structural

Screws

• Type I – Hex cap
• Type II – Socket head cap

Nuts

• Type I – Hex
• Type II – Hex jam
• Type III – Heavy hex
• Type IV – Heavy hex jam
• Type V – Hex slotted