1/2″ to 4″ Heavy Duty Industrial LOCKnuts (HDI Series)
Solid Steel Precision Machined & Made in the USA

Why deal with stamped locknuts that warp, strip, crack, or worse yet fail?

Consider the NEXT Generation of locknuts…AMFICO’S HDI Series Steel LOCKnut,
Guaranteed to Grip Tight, Thread Right & Never Vibrate Loose!
Unique diamond-cut knurl facing will bond to all metal enclosures & never damage non-metallic boxes.
Fully Reuseable

Will EXCEED Your EXPECTATION NOT Your Budget.  A True Cost-Effective Solution. 

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Steel Locknut Made in the USA 1/2" to 4"

AMFICO HDI Series Locknuts Steel USA

You know its superior because it’s AMERICAN.

End your locknut frustration by installing with our HDI Series Steel LOCKnuts. This LOCKnutt will end all your frustration with warped locknuts, cracked locknuts, and locknuts that simply spin & do not lock.  Our steel LOCKnut threads easily and even has a notched area to make your bump lock easy.

All HDI Locknuts are made in our factory in New Jersey. They start from alloy bar stock and precision machined to provide a lifetime of service. They will lock TIGHT & RIGHT every time. Never worry about vibration, they are test proven in major transit, bridge, and airport projects. 

AMFICO HDI Series Industrial Grade Solid Steel Locknuts Made in the USA

Cat Numbers & Dimensions

Steel Locknuts HDI Series USA AMFICO


Material Construction:  Alloy Steel, Zinc Plated with Chromate Finish
Solid Steel Construction Fully Precision Machined
Galvanized Plating Option Available


Diamond Cut Facing for Full Bonding
Cannot Vibrate Loose
Will Not Damage Non Metallic Enclosures
Notched Indents to Assist in “Bump & Lock”
Flat Hex Surfaces Precision Cut Threads for EZ Torque


Certified Made in the USA

UL Listed to 514B
NEMA Standard FB1
Federal Standard A-A-50553
UL Standards: 514B, 467
CSA Standard: C22.2 No. 18F
RoHS Compliant
REACH Compliant
CA Prop 65 Compliant
UNSPSC 39131311

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