Metric Class 8 Half Nuts for Compact Threaded Assemblies

Not every threaded connection has room for a full-height nut. Bremick Hex Lock Nuts provide a lower-profile option for compatible metric assemblies where a half nut, Class 8 specification & galvanised finish are required. Also known as half nuts, hex half nuts, metric lock nuts, low-profile hex nuts or jam nuts in some applications, they're useful when nut height, thread fit & available clearance all matter.

The important detail is that a thinner nut shouldn't be selected on profile alone. When replacing an existing half nut or working from an equipment drawing, check the nominal thread diameter, thread pitch, property class, finish, nut height & mating fastener. Two nuts can appear similar on the bench while differing in a way that makes one unsuitable for the connection. If a replacement doesn't start cleanly on the mating thread, don't force it. Recheck the thread specification & inspect both components for damage or contamination.

This Bremick range covers Metric Class 8 galvanised half nuts from M12 to M36, making it relevant to machinery maintenance, adjustment mechanisms, fabrication & compatible industrial threaded assemblies. The reduced-height design can also be used within specified jam-nut arrangements, but the required locking method, thread engagement & installation sequence should always follow the equipment or assembly requirements.

Replacing a conventional full-height nut instead? Compare the available options under Hex Nut. Building the rest of the threaded assembly? Browse Bolts & Fasteners for related fastening hardware.

What Are Bremick Hex Lock Nuts?

A half nut is more than a thinner-looking version of a standard nut.

The Bremick Hex Lock Nuts in this collection use reduced-height hex geometry for compatible threaded assemblies where this particular nut style is specified.

The current range features:

► Metric threads
► Class 8 specification
► Galvanised finish
► Reduced-height half-nut design
► External hex profile
► Sizes from M12 to M36

Depending on the industry or application, similar terminology can include thin hex nuts, reduced-height nuts, locking half nuts, metric half nuts & jam nuts.

The terminology is useful when searching for replacement hardware, but the physical specification should always make the final decision.

For the wider family of nuts, washers & fastening components, browse Nuts & Washers.

Why Choose Bremick Hex Lock Nuts?

When a Full-Height Nut Takes Up Too Much Room

Picture a threaded adjuster running close to a machine bracket.

The thread is correct. The diameter is correct. But a conventional hex nut occupies more axial space than the assembly was designed to accommodate.

That's where a correctly specified low-profile lock nut can make sense.

Bremick half nuts can be relevant around compatible:

► Threaded adjustment mechanisms
► Positioning components
► Machinery linkages
► Equipment supports
► Restricted-clearance connections
► Mechanical assemblies
► Specified double-nut arrangements

Reduced height is useful, but it also changes the geometry of the connection. A half nut shouldn't replace a standard nut purely because it's more compact.

Useful When Matching Existing Equipment

Maintenance work often starts with an old component sitting on the bench.

Instead of ordering “another lock nut”, clean the original hardware & identify what it actually is.

Check:

► Metric diameter
► Thread pitch
► Nut thickness
► Property class
► Surface finish
► Mating bolt or stud
► Position within the assembly

A description such as M20 Class 8 galvanised half nut is far more useful than “thin M20 nut”.

Common Applications

Machinery Adjustment Points

Some threaded assemblies are designed to establish a position before securing that adjustment.

Compatible applications can include:

► Mechanical stops
► Threaded spindles
► Machine linkages
► Equipment supports
► Positioning mechanisms
► Adjustable brackets

Where a half nut forms part of the original arrangement, replacing it with the same style helps maintain the intended assembly geometry.

Agricultural Equipment Repairs

Farm machinery can be hard on fastening hardware.

Dirt, moisture, old paint, corrosion & previous repairs can make a metric half nut difficult to identify while it's still installed.

Remove the component where practical, clean the threads & inspect the nut before ordering.

For unusual fastening requirements beyond standard nuts & bolts, browse Specialty Fasteners.

Fabricated Equipment With Limited Clearance

Fabricated frames, brackets & mechanical components can leave little room around a threaded connection.

A thin hex nut or reduced-height nut may suit applications designed around limited axial space.

Before changing from a full-height nut, consider:

► Available thread engagement
► Joint design
► Property class
► Loading conditions
► Mating component
► Intended locking method

Saving a few millimetres isn't useful if the replacement no longer suits the connection.

Workshop Maintenance Stock

Mixed nut bins create avoidable mistakes.

A half nut can easily disappear among conventional hex nuts, particularly when several metric sizes & finishes are stored together.

Clear bin labels can include:

► M20
► Thread pitch
► Half Nut
► Class 8
► Galvanised

For maintenance stores carrying several metric lock nut styles, separating them by design can make repeat repairs considerably easier.

Product Selection Guide

Start With the Size Range

The current Bremick Metric Galvanised Class 8 Hex Lock Nut range includes:

Once you've identified the nominal diameter, confirm the remaining details before treating the selection as complete.

Half Nut vs Standard Hex Nut

Both can look familiar on the workbench, but their geometry differs.

If the assembly calls for conventional nut geometry, browse Hex Nut.

Half Nut vs Nylon Insert Lock Nut

Search for “lock nuts” & you'll find several different designs.

A locking half nut doesn't use the nylon insert found in a Nyloc-style nut.

If the existing component has a visible nylon ring, browse Nylon Insert Nut.

Half Nut vs Flange Nut

These nut types solve different problems.

A half nut focuses on reduced height. A flange nut incorporates a wider flange beneath the hex body.

Where the connection calls for a flanged nut design, browse Flange Nut.

Don't Use Spanner Size as Thread Size

Here's an easy mistake to avoid.

A nut that takes a particular spanner size doesn't necessarily have a thread of the same nominal diameter.

Across-flats dimensions describe the outside hex. Metric thread size describes the mating thread.

When identifying an unknown hex half nut, check measurements such as:

► Thread diameter
► Thread pitch
► Nut thickness
► Across-flats dimension where useful

For workshop dimensional checks, browse Calipers (Digital / Manual).

Check the Thread Pitch

An M20 nut isn't necessarily suitable for every M20 threaded component.

Pitch still matters.

Before installation:

► Compare the old & new components
► Inspect the mating thread
► Confirm pitch where required
► Clean contamination from the threads
► Begin engagement carefully

A correct nut shouldn't need to be forced through the first few turns.

If resistance appears immediately, investigate before continuing.

Confirm the Class 8 Requirement

The current metric galvanised products in this Bremick collection are specified as Class 8 lock nuts.

Property class forms part of the fastener specification.

When replacing hardware, compare the required class against:

► Equipment documentation
► Engineering drawings
► Fastening schedules
► Mating fastener requirements
► Original component identification

The fact that another nut has the same diameter doesn't make its property class equivalent.

Match the Galvanised Finish

The products covered here use a galvanised finish.

Finish should be included when identifying replacement hardware, particularly when the original assembly has been specified around particular materials or exposure conditions.

Consider:

► Existing bolt or stud finish
► Connected materials
► Moisture exposure
► Environmental conditions
► Equipment requirements
► Maintenance history

A stainless, plain or differently coated nut shouldn't automatically replace a galvanised lock nut simply because the thread fits.

Using a Half Nut as a Jam Nut?

The term jam nut is commonly associated with reduced-height nuts used in certain double-nut locking arrangements.

That doesn't mean every half nut should automatically be installed that way.

Where the equipment uses a jam-nut arrangement, establish:

► Which nut belongs in each position
► Required thread engagement
► Tightening sequence
► Final adjustment position
► Condition of the mating thread
► Equipment instructions

If you're dismantling an unfamiliar mechanism, photograph the arrangement before removing the hardware.

That reference can be surprisingly valuable during reassembly.

Inspect the Bolt, Stud or Spindle

A replacement nut only works as well as the thread it engages.

With the connection apart, inspect the mating component for:

► Flattened thread crests
► Cross-threading
► Corrosion
► Impact damage
► Embedded debris
► Distortion
► Previous forced assembly

Where associated bolted hardware also requires replacement, browse Structural Fasteners & Bolts.

Check the Washer Arrangement

Some connections use a washer. Others don't.

Follow the requirements of the individual assembly rather than copying another fastening point nearby.

Where a washer is specified, check:

► Inside diameter
► Outside diameter
► Thickness
► Material
► Finish
► Condition

Browse Flat Washer for related conventional washer options.

Expert Tips

Use the old hardware as evidence. Clean it, measure it & record what you find before placing the replacement order.

Include “half nut” in workshop descriptions. It immediately distinguishes the component from many other lock-nut designs.

Label recurring stock properly. Diameter, pitch, class, finish & nut style are more useful than diameter alone.

Compare thickness when sorting loose nuts. Reduced height is a useful visual clue when separating half nuts from standard hex nuts.

Don't force the first turn. Immediate resistance can indicate dirt, damage or incompatible threads.

Keep nylon insert nuts separate. Both products may be described as lock nuts, but their construction & intended locking methods differ.

Check the male thread before blaming the nut. Damage to a bolt, stud or spindle can prevent a new nut from engaging correctly.

Bag dismantled hardware by machine or assembly. This reduces mix-ups when several repairs are happening at once.

Mark adjustment positions before disassembly where appropriate. It can make returning a mechanism to its previous setup easier.

Record repeat-use parts. Once a maintenance team has identified the correct M12, M16, M20, M24, M30 or M36 half nut, keep that information with the equipment record.

For a broader introduction to threaded hardware & fixing types, read Fastener Guide Bolts Screws Anchors.

Working on machinery where small hardware issues can contribute to larger maintenance delays? Quarry Crews Crusher Maintenance looks at equipment maintenance in demanding working environments.

Choosing the correct nut is only one part of building a reliable threaded connection. Why Good Fasteners Matter More Than the Tool You Drive Them With explores why fastener selection deserves attention in its own right.