Keps K Lock Nuts in 304 Stainless Steel

Hex Nuts with an Attached Free-Spinning Washer

A Keps K-lock nut is a nut with an attached or captive, free-spinning washer. They may also be referred to as Keps Nuts, k-lock nuts, star nuts, or captive lock washer nuts. They are used to make an assembly more convenient as they combine both a hex nut and a lock washer into a single fastener.

K Lock Nuts Feature a conical external tooth washer attached to the bottom of the nut. This integrated lock washer bites into the surface material, providing increased breakaway torque and decreased likelihood of the nut loosening.

Stainless Steel

18-8 or 304 grades of Stainless steel are suitable for many general purpose applications, especially freshwater and non-salt water wet environments. Corrosion-resistant and durable, 18-8 stainless steel is equivalent to the A2 grade of stainless steel.

Nut Size
Width Across Flats Overall Thickness Washer Diameter
#4
1/4" Max 0.098 - Min 0.087
Max 0.286 - Min 0.277
#6
5/16" Max 0.114 - Min 0.102 Max 0.348 - Min 0.338
#8
11/32" Max 0.130 - Min 0.117 Max 0.381 - Min 0.370
#10
3/8" Max 0.130 - Min 0.117 Max 0.406 - Min 0.395
1/4" 7/16" Max 0.193 - Min 0.178 Max 0.506 - Min 0.494
5/16" 1/2" Max 0.273 - Min 0.258 Max 0.592 - Min 0.579
3/8" 9/16" Max 0.385 - Min 0.365 Max 0.665 - Min 0.651

FAQs

How do K nuts work?

Keps K lock nuts are standard hex nuts with a free-spinning captive serrated washer attached. This washer bites into the surface material to help the nut resist vibration. Keps nuts effectively combine hex nuts with external tooth lock washers into a single fastener for ease of use.

What is the main difference between a KEPS nut and a Nylock nut?

Keps nuts use a serrated captive washer that's attached to the nut to bite into the surface material to create tension and resist vibration. Nylock nuts use a nylon insert that the screw will cut threads into, creating friction between the screw threads and the nylon to prevent loosening. Both are lock nuts, but their methods of locking are their main difference.

What are locking nuts for?

Lock nuts are an easy to use, cost-effective solution to protecting against vibration-related loosening. They're used to protect applications from loosening over time.

What is stainless steel good for?

Stainless steel is good for general purpose applications, especially those involving water or freshwater. Suppose you need stainless steel for more corrosive environments, such as marine or salt-water applications. In that case, we recommend the 316 grade of stainless steel.

Can I use stainless steel nuts with bolts of a different metal?

Depends on the material. Some materials, such as zinc plated steel, are safe to mix with stainless steel. However, aluminum is not safe to use because it risks galvanic corrosion of the materials. We recommend keeping like-metals together in applications.