Hex Jam Nuts

Hexagonal Thin Nuts For Locking Against Each Other

Jam nuts, also known aptly as thin nuts, are low profile hex nuts about 2/3rd the thickness of a standard hex finish nut. They are commonly used as a kind of locknut but may also be found in situations where a standard nut would not fit.

A jam nut is often used when a nut needs to be locked in place without clamping against another object. The jam nut essentially acts as the "other object," as the two nuts are tightened against each other. They can also be used to secure an item on a fastener without applying force to that object. This is achieved by first tightening one of the nuts onto the item. Then the other nut is screwed down on top of the first nut. The inner nut is then slackened back and tightened against the outer nut.

This locking action helps to avoid compression of the part being fastened while also locking it in place but still rotate freely, such as in bearings. The idea behind a jam nut is that a thin nut exerts less overall force than a fully torqued standard nut. They're the opposite of most heavy styles for nuts.

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.

For much more corrosive environments, such as in saltwater or marine applications, 316 stainless steel is the ideal choice. 316 Stainless steel is equivalent to A4 stainless steel.

Black Oxide Coating

18-8 stainless steel hex nuts are available in a black oxide coating, which adds mild corrosion and abrasion resistance, but is mostly used for the color.

Zinc Plated Steel

Zinc is by far the most common and economical type of plating for fasteners. The zinc plating adds a protective "sacrificial" top layer against corrosion while also adding a shiny finish to the fastener. Zinc plating is ideal for indoor use where it won't be constantly exposed to harsh elements.

Brass

Brass is an alloy made of copper and zinc. The color of brass can vary from dark to light based on the zinc content; more zinc content produces lighter brass. Brass is prized for its appearance and is often used decoratively. However, it is quite soft, so it is not suitable for all applications. Brass conducts electricity and is also a good conductor of heat.

Silicon Bronze

Silicon bronze fasteners are made of copper, silicon, and various other alloys such as zinc, tin, iron, and manganese. The color of silicon bronze may vary based on the amount of copper in the fastener.

Not sure what material you need? Check out our Material Guide to find the right material for your needs!

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FAQs

What is a jam nut used for?

Jam nuts are low profile nuts commonly used as a type of locknut, where it is "jammed" up against another nut. With both nuts being fastened towards each other, this effectively locks the assembly in place. You may also find these nuts used in applications where a standard nut won't fit.

What is the jam nut method?

The jam nut method, sometimes known as the "double nut" method, is a friction locking method that uses two separate nuts fastened towards and against each other. Thus, the two nuts are bearing in opposite directions on the threads creating the "jam" effect.

How do you loosen jam nuts?

To loosen jam nuts, you can either take the outer nut off first and remove it like any other nut, or put a wrench on each nut and turn them in opposite directions to unfasten them from the assembly.

Why are jam nuts thinner?

Jam nuts are thinner because it helps save space when locking a pair of nuts together. The thinner size also means the jam nut exerts less overall force when fully torqued, so the standard nut can exert more force on the jam nut when they are fastened together without potentially damaging the material you're fastening to.

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.

What is black oxide used for?

Black oxide is used to add mild corrosion resistance, abrasion resistance, for appearances, and to minimize light reflection.

What is zinc plated steel?

Zinc plated steel is steel that goes through the process of adding a layer or coating of zinc to protect the steel from corrosion. The added layer of zinc sacrifices itself to keep the steel from rusting, even if the plating is damaged.

How strong is brass?

Brass is stronger and harder than copper, but not as strong or hard as steel. It has great formability and is resistant to saltwater corrosion.

What is silicon bronze?

Silicon bronze is an alloy made of copper, silicon, and various other alloys such as zinc, tin, iron, and manganese. It's known for its appealing surface finish and superior corrosion resistant properties, even when submerged in saltwater.