Positive Shaft & Hub Retention
One small screw can decide whether a pulley stays aligned or starts walking along its shaft. Bremick Knurled Cup Point Socket Set Screws give Australian machinery workshops, fabricators, manufacturers & maintenance teams a compact headless fastener for retaining compatible pulleys, collars, hubs & other shaft-mounted components.
Known across Australian workshops as knurled grub screws, socket set screws & knurled cup point grub screws, the Bremick metric range combines a recessed hex drive with a knurled cup point. Bremick documents its metric coarse range to DIN 916, Class 14.9 with a plain finish, covering diameters from M3 through M16. Browse Specialty Fasteners for related fastening options, or Power Transmission when the repair extends into shafts, hubs or drive components.
The important detail is hidden at the end of the screw. Unlike a conventional bolt that clamps beneath a head, a set screw advances through its tapped component until the point engages the mating surface.
What Are Knurled Cup Point Socket Set Screws?
A headless fastener solves a particular machinery problem: holding one component against another without leaving a bolt head projecting from the assembly.
Socket set screws are fully threaded, headless fasteners driven through an internal hex socket. In shaft-mounted applications, the screw typically passes through a tapped hole in a pulley, collar, hub or similar component until its point contacts the shaft.
Australian trade terminology commonly includes:
► Knurled cup point socket set screws
► Knurled cup point grub screws
► Knurled grub screws
► Socket set screws
► Grub screws
► Socket grub screws
► Hex socket set screws
► Headless set screws
► Metric grub screws
► DIN 916 set screws
► Shaft set screws
► Pulley grub screws
Bremick's documented metric version is a Class 14.9 plain-finish knurled cup point screw manufactured to DIN 916. That specification is far more useful when identifying a replacement than simply asking for “a little grub screw”.
For a broader look at how different fasteners suit different assemblies, read Fastener Guide Bolts Screws Anchors.
Why Choose Knurled Cup Point Socket Set Screws?
Rotating equipment leaves little room for a fastener that protrudes unnecessarily from a hub or collar.
The headless design allows the set screw to sit within its tapped component while the cup point creates concentrated contact against the mating surface.
Useful characteristics include:
► Compact headless installation
► Internal hex drive
► Knurled cup point contact
► Class 14.9 metric construction
► Metric coarse thread
► DIN 916 configuration
► M3–M16 documented diameter range
► Plain finish
► Positive engagement against compatible mating surfaces
Knurled contact should be selected deliberately rather than treated as universally better. The point can mark or indent a shaft, so applications involving polished surfaces, frequent repositioning or sensitive components may call for another point style.
For socket-driven fasteners that clamp beneath a conventional head rather than bearing through a point, compare Socket Head Bolts.
Common Applications
Machinery rarely advertises the importance of a set screw until the component it retains begins to move.
Knurled cup point grub screws are commonly associated with compatible:
► Pulleys
► Shaft collars
► Hubs
► Couplings
► Gears
► Sprockets
► Drive components
► Machinery adjustments
► Workshop equipment
► Fabricated assemblies
► Motor-driven equipment
► Maintenance replacements
Picture a pulley mounted on a motor shaft. The grub screw advances through the threaded pulley hub until its point bears against the shaft, helping retain the pulley in its intended position.
A shaft collar presents a similar-looking job with different consequences. Its location may control a bearing, spacer or adjoining component, making correct thread, length & point selection important during replacement.
Coupling maintenance brings alignment into the conversation. If a hub repeatedly moves after tightening, inspect the wider assembly rather than assuming a stronger turn on the hex key will solve the underlying problem.
Legacy machinery creates another challenge for Australian maintenance stores. Metric & imperial fasteners can coexist across equipment of different ages, so visual similarity isn't enough to identify an unknown set screw.
For machinery assembly, holding & repair equipment around the workshop, browse Workshop Equipment.
Product Selection Guide
The quickest route to the correct replacement is to identify the old screw completely before opening the parts drawer.
Confirm The Thread First
Two grub screws can look almost identical on the bench & still belong to completely different tapped holes.
Check:
► Thread diameter
► Thread pitch or TPI
► Metric or imperial thread
► Overall length
► Point configuration
► Hex socket size
► Existing tapped hole
Bremick's documented metric knurled cup point range uses metric coarse threads.
Never force a near-fitting thread into an existing hub or collar. Damaging the female thread can turn a simple fastener replacement into a component repair.
Match The Bremick Metric Size
Bremick's catalogue gives maintenance buyers a useful diameter-to-drive reference rather than leaving identification to guesswork.
|
Metric Diameter
|
Documented Hex Wrench A/F
|
Documented Length Range
|
|
M3
|
1.5 mm
|
3–5 mm
|
|
M4
|
2 mm
|
4–25 mm
|
|
M5
|
2.5 mm
|
5–20 mm
|
|
M6
|
3 mm
|
6–50 mm
|
|
M8
|
4 mm
|
8–35 mm
|
|
M10
|
5 mm
|
10–50 mm
|
|
M12
|
6 mm
|
12–40 mm
|
|
M16
|
8 mm
|
20–50 mm
|
Not every length exists within every diameter. Match the required combination against the available collection product rather than assuming every intermediate length is produced.
For checking diameter & overall length during identification, Calipers (Digital / Manual) can help remove uncertainty from a workshop replacement.
Confirm The Point Style
Turn the removed screw around before deciding you've found its replacement.
Common socket set screw point styles can include:
|
Point Style
|
Practical Selection Consideration
|
|
Knurled cup point
|
Positive engagement where the point may bite into the mating surface
|
|
Cup point
|
Concentrated general-purpose shaft contact
|
|
Flat point
|
Broader contact where less aggressive engagement may be preferred
|
|
Cone point
|
Concentrated point contact for suitable applications
|
|
Dog point
|
Locating engagement where the assembly provides a corresponding feature
|
A knurled cup point shouldn't automatically replace another point configuration merely because the thread fits.
Decide Whether Shaft Marking Is Acceptable
The same feature that helps a set screw grip can leave a witness mark behind.
Before selecting a knurled cup point, consider whether the mating surface is:
► A general machinery shaft
► Precision ground
► Polished or plated
► Regularly repositioned
► Intended to remain unmarked
► Provided with a dedicated contact flat
Where surface condition matters, confirm that this point style suits the machinery design.
Choose The Correct Length
Length controls where the point reaches, how much thread remains engaged & whether the screw finishes neatly inside the component.
Check that the selected length:
► Reaches the intended contact surface
► Provides appropriate thread engagement
► Doesn't bottom unexpectedly
► Doesn't protrude into an interference area
► Leaves the socket accessible for future maintenance
More length isn't automatically more secure. The correct screw needs to suit the depth & geometry of the actual assembly.
Match The Hex Key Exactly
A rounded internal socket can turn a five-minute replacement into an extraction job.
Bremick's documented wrench sizes progress from 1.5 mm A/F for M3 through to 8 mm A/F for M16.
Use the correct key, seat it fully & avoid substituting an imperial tool simply because it feels close.
For workshop fastening tools used during installation & removal, browse Spanner & Wrench Sets.
Inspect The Contact Area
Witness marks on a shaft can reveal both where the previous screw sat & how the assembly has behaved.
Look for:
► Existing indentations
► Burrs
► Scoring
► Wear
► Corrosion
► Dedicated flats
► Repeated set-screw marks
► Signs the component has shifted
A damaged contact area deserves investigation before another screw is tightened into exactly the same location.
Expert Tips
Keep the removed grub screw attached to the maintenance job until the replacement is confirmed. Diameter, pitch, length & point style are easier to compare with the original in hand.
Clear debris from the internal socket before inserting the key. Grease, paint, swarf or dirt can prevent full engagement & increase the risk of damaging the hex.
Use Bremick's documented wrench size as an identification cross-check. An M6 knurled cup point uses a 3 mm A/F hex while an M10 uses 5 mm, providing another useful clue when sorting workshop stock.
Inspect the tapped component when a screw repeatedly works loose. Worn female threads or damaged engagement can't be corrected simply by installing another set screw.
Check alignment before blaming the fastener for recurring movement. Pulley, coupling or hub problems may originate elsewhere in the rotating assembly.
Separate metric & imperial maintenance stock clearly. Similar-looking grub screws are particularly easy to mix when a workshop services machinery from different manufacturers & eras.
Record frequently replaced screws against the machine itself. “M8 x 16 knurled cup point” gives the next technician considerably more information than a drawer labelled “grub screws”.
For maintenance teams dealing with demanding industrial equipment, Quarry Crews Crusher Maintenance offers another practical look at keeping machinery working.
For a broader perspective on the importance of correctly selected hardware, read Why Good Fasteners Matter More Than the Tool You Drive Them With.
Workshops reviewing everyday maintenance tools can also explore Kincrome vs SP Tools: Workshop Hand Tool Showdown.
