MIL-I-8846 Military Specifications Fasteners

Mil spec MIL-I-8846 covers helical coil screw-thread inserts made from formed wire, the inner surfaces of which, after assembly, provide threads as specified.

Type I – Coarse thread

• Class 1 – Free running
• Class 2 – Screw locking (self-locking)

Type II – Fine thread

• Class 1 – Free running
• Class 2 – Screw locking (self-locking)

Type III – Taper pipe thread

• Class 5 – NPT pipe thread
• Class 6 – ANPT pipe thread

Type IV – Metric

• Class 3 – Staking (spark plug thread)