Lock Nuts

Lock nuts do not readily loosen when placed on bolts. This makes them useful for holding wheels onto axles, or in automotive engines where machine vibration would otherwise loosen the fastener. Lock nuts may also be used as jam nuts, threaded over another nut to keep it in place.

Finish

Black Oxide

An extremely thin attractive finish with minimal corrosion resistance. This coating reduces galling, improves lubrication of mating parts and reduces glare. This finish looks great when trying to achieve a stylish or "high-tech" look on exposed fastener heads.
Cadmium

Offers good corrosion resistance in a very thin layer. Meaning that part with low tolerances still fit together with this plating. Used mainly in the aerospace and aviation industries. Easily paintable.
Chrome

This finish improves appearance and provides mild corrosion resistance. It can also increase surface hardness, which improve abrasion resistance, reduces friction, and prevents seizing. This finish is shiny and aesthetically pleasing.
Plain

Nothing has been done to this bare metal surface to improve appearance or corrosion resistance, which is very low if the material is steel. Often the surface has been oiled which improves lubricity. This finish is susceptible to rusting and corrosion in exterior environments. This most basic finish can be used when protection is not an issue or indoors.
Yellow Zinc

This iridescent electroplated zinc finish, also known as Yellow Zinc Chromate or Dichromate, provides very good corrosion resistance and protection against rust. This finish should not be used in marine or high salt spray environments.
Zinc

This finish, also know as zinc plating, zinc chromate or dichromate provides good corrosion resistance and is the standard for many hardware fasteners. It is an electroplated zinc layer covered with a chromate post-treatment. The zinc protects the steel from corrosion and the chromate layer protects the zinc from degrading. It is a popular finish because of its protection, value, and ease of coating. Slightly less corrosion resistant than yellow zinc, it is a versatile finish that is best used indoors. This finish should not be used in marine or high salt spray environments.

Grade

2

This grade is from the SAE scale and made of low carbon steel. This classification is low on the grade scale.
2H

This is a high pressure and temperature grade nut made of medium carbon steel that has been quenched and tempered. This grade meets ASTM specification A 194. These nuts are also used in flanges and fittings as well as in heavy construction of buildings and bridges.
5

This grade is from the SAE scale. Made of medium to low carbon steel, it is of medium strength on the grade scale.
8

This grade is part of the SAE classification; it is the minimum standard of the automotive and structural industries, plus it is used in high-temperature applications. Grade 8 is near the high end of the grade scale, although there are higher grades and strengths for more specialized fasteners.
9

At the top of the scale, this grade offers the most strength in a joint. There are no industry standards for this grade, however most have tensile strengths around 180,000 psi. This grade is used in high strength applications.
18-8

A general designation for the most common and popular stainless steel, (300 Series) referring to the 18% chromium and 8% nickel. It's strength has a range from the middle to low end of the grade scale. All 300 series stainless steel share the ratio of chromium to nickel with varying other elements improving different properties. It has higher corrosion resistance than the 400 series stainless steels and it is non-magnetic.
316

The second most common stainless steel grade, this material is stronger than grade 2, slightly weaker than grade 5,or generally as strong as medium to low carbon steel. It is on the low middle end of the grade scale. It is used in more severe corrosive environments than 304 stainless steel, as such it is used in more industrial settings, like process chemicals, textiles, bleaches, salt water and rubber. It is also used in surgical implants. The DIN/ISO denotation for a very similar grade is A4-70.
6061-T6

The least expensive and most popular aluminum alloy, 6061 has good mechanical properties, good welding properties, and corrosion resistance plus it is the most versatile heat-treated aluminum. The T6 temper designation means it is the strongest of the 6061 aluminum alloys with a tensile strength around 40,000 psi.
A

This grade is used in low strength applications. This grade meets ASTM specifications for A563 and is typically used with ASTM Grade A and B bolts or SAE grade 1 and 2 bolts.
A2

A type of the most common stainless steel grade. It is comparable in strength to grade 2 materials, yet slightly weaker and easy to weld. This grade is always metric. The ASTM denotation for very similar grade is 304. The corrosion resistance and ease of fabrication are why this grade is used in food industry machines, appliances, architectural trim and aquatic fasteners.

Material

Aluminum

Aluminum fasteners are a light weight alternative to steel fasteners. Aluminum is soft, non-magnetic, and corrosion resistant. These fasteners offer good electrical and thermal conductivity, and a good strength-to-weight ratio.
Brass

Brass is a soft, non-magnetic fastener material that offers corrosion resistance, heat and electrical conductivity, and cosmetic appeal. Brass fasteners may be found in electronics, plumbing, and marine applications.
Stainless Steel

Stainless steel is steel combined with alloying elements, principally chromium, to enhance corrosion resistance and impart other desired properties depending upon the alloying elements in use and their proportions. Many stainless steel fasteners are non-magnetic or less magnetic than regular steel fasteners.
Steel

Steel is the most common fastener material due to its strength properties. Unalloyed steel may be surface treated to enhance corrosion resistance and other desirable properties.

Series

N1268

This series is two to three times taller than a normal nut and features a nylon insert around the hole where the bolt exits. This the increases thread length plus the nylon molded interior threads are what lock the nut in place and resist loosening.
NE

This series has a nylon insert at one end of the nut, where the bolt shank exits. This insert is designed to be slightly smaller that the diameter of the bolt or cap screw and its deformation helps to lock the nut in place. The E in NE denotes that these nuts are to be used with imperial or unified measured bolts and cap screws.
NM

This series has a nylon insert at one end of the nut, where the bolt shank exits. This insert is designed to be slightly smaller that the diameter of the bolt or screw and its deformation helps to lock the nut in place. The M in NM denotes that these nuts are to be used with metric measured bolts and cap screws.
NTE

Similar to the NE series this series has a nylon insert at one end of the nut, where the bolt shank exits. This insert is designed to be slightly smaller that the diameter of the bolt or cap screw and its deformation helps to lock the nut in place. The NTE nut is about half the height of the NE series for a lower profile jam nut look. The E in NTE denotes that these nuts are to be used with imperial or unified measured bolts and cap screws.
NTE8

Exactly the same as the NTE series with its low profile jam nut look and nylon insert at one end of the nut, where the bolt shank exits. The difference is the 8 denotes the grade 8 high strength use of this nut. The E in NTE8 denotes that these nuts are to be used with imperial or unified measured bots and cap screws.
NTM

Similar to the NM series this series has a nylon insert at one end of the nut, where the bolt shank exits. This insert is designed to be slightly smaller that the diameter of the bolt or cap screw and its deformation helps to lock the nut in place. The NTM nut is about half the height of the NM series for a lower profile jam nut look. The M in NTM denotes that these nuts are to be used with metric measured bolts and cap screws.
NU

This heavy duty series has a nylon insert at one end of the nut, where the bolt shank exits. This insert is designed to be slightly smaller that the diameter of the bolt or cap screw and its deformation helps to lock the nut in place.

Specification

DIN 980

Meets German standards for metric series all metal fabrication locknuts.
DIN 982

Meets German standards for metric series nylon insert heavy locknuts.
DIN 985

Meets German standards for metric series nylon insert locknuts.

Style

Double Notch

This type of lock nut is two or three times as tall as a normal nut, increasing the bearing surface on the thread and increasing locking force.
Heavy

This style of nut refers to its larger height and width and consequently higher strength compared to other nuts . It is slightly larger, stronger and more durable than the average nut and is therefore termed "heavy". These nuts are often used in structural fastening for large scale construction.
Heavy Jam

This style of nut refers to its larger height and width and consequently higher strength compared to other jam nuts . There is a circular nylon insert at one end of the nut which is deformed as the shank of a fastener is threaded. This deformation locks the nut in place with more force.
Jam

This style is any nut that approximately half the height of a normal nut. Called a "jam" nut because it is used to lock a normal sized nut in place by threading right up against the first nut.
Security Heavy Hex - Steel Insert

This style from the Security Locknut company is the heavy design, and uses a steel insert to lock the nut in place. Effective in temperatures up to 700°F, reusable for 50+ installations, and resistant of extreme vibration conditions.

System of Measurement

Metric

Also known as the SI system, this measurement system is used across the globe. It is based on multiples of ten and uses meters, centimeters, millimeters as its basic measurements.

Type

Flexible Lock Nut

Flexible lock nuts have a slotted top section that expands and creates a locking force as it comes into contact with the threads of the mating fastener.
K-Lock Nut

K-lock nuts resist loosening with external tooth locking washers attached to the underside of the nut, which bear into the mating surface. This pre-assembled design saves time.
Lock Nut

Lock nuts include various kinds of nuts that use friction to prevent loosening of the nut, often in applications where vibration is present.
Nylon Insert Lock Nut

Nylon insert lock nuts have a nylon collar that creates friction between the threads of the nut and the threads of the mated fastener, resisting loosening due to vibration.
Reverse Lock Nut

Reverse lock nuts are for use with left hand threaded fasteners.
Top Lock Nut

Top lock nuts have a crimped top section that creates a locking thread distortion with the mated fastener. Top lock nuts may only be installed in one direction.