How to Choose a Reliable Set Screws / Grub Screws Manufacturer, Wholesaler, Supplier & Exporter

Set screws (grub screws) do their job entirely below the surface of the component they're threaded into, which means the point geometry — not the thread — is what actually determines how well they hold a shaft in place. Buyers who order "set screws" without specifying point type are leaving the single most important performance decision to whoever fills the order. A supplier should always ask which point type (cup, cone, flat, or dog) your application needs, rather than defaulting to whichever is fastest to produce.

Cup point is the practical default for a reason: the small circular ridge it leaves indents the shaft slightly, giving genuinely repeatable holding power across removal and reinstallation cycles that a flat point can't match. Cone point holds harder for a one-time, permanent installation, at the cost of marking the shaft more deeply — which matters if the shaft ever needs to be reused elsewhere. Flat point is used against a hardened or finished shaft surface where marking isn't acceptable at all.

Not specifying point type is the single biggest ordering mistake — point geometry, not thread size, is the main performance variable, and cup, cone, and flat points behave very differently under the same torque. Using cone point on a shaft that needs to be reused is another frequent error, since cone points mark the shaft permanently and deeply, making cup point the better choice where the shaft may later be relocated or serviced.

Alloy steel 45H is standard for shaft-locking applications requiring hardness at the point tip; stainless steel A2/A4 is used where corrosion resistance matters more than maximum holding force. Point geometry and hardness should be verified against the relevant DIN standard (913 flat, 914 cone, 915 dog, 916 cup) before shipment.

Set screws rely entirely on point-to-shaft friction and indentation, and under-torquing on a vibrating shaft is the most common cause of slippage in service. A supplier familiar with power-transmission applications should be able to advise on appropriate installation torque for your specific size and point type, not just ship the part with no guidance.

A standard 20ft container (~20 tons) typically holds 3 to 5 million pieces of set screws in common sizes (M6-M8) — exact quantity depends on size and point type and should be confirmed at quote time.

• Which point type — cup, cone, flat, or dog — does my shaft-locking application actually need?

• Will this shaft need to be reused or relocated later, and does that change your point-type recommendation?

• How is point geometry and hardness verified against the relevant DIN standard?

• What installation torque do you recommend for this size and point type on a vibrating shaft?

Pulleys and collars needing positive shaft locking are the most common application, typically using cup-point set screws for repeatable removal and reinstallation. Gears and couplings locking onto shafts often use cone point for a more permanent, higher-holding-power connection. Machine tool fixtures needing fine positioning and locking in jigs and fixtures commonly specify flat point where the shaft surface is already finished or hardened and shouldn't be marked.

Alloy steel 45H with black oxide finish is the standard, cost-effective choice for most power-transmission applications. Stainless steel A2/A4 variants cost more but are worth specifying for corrosive or washdown environments where a rusted set screw could seize permanently in place, making future maintenance far more difficult.

Common sizes (M6-M8) with cup or cone points are typically ready stock. Less common point types (dog point) and stainless variants in larger sizes may require a short production run.

For point geometry and hardness verified against a specific power-transmission application, you're evaluating a manufacturer's process control. For common sizes and point types at volume, wholesale pricing matters most. Machinery OEMs with a fixed shaft-locking specification typically want a stable supplier relationship, while distributors need an exporter comfortable with small-parts bulk packing for OEM assembly lines.

• Point type confirmed (cup, cone, flat, or dog) against repeatable vs. permanent holding requirements.

• Material confirmed (alloy steel vs. stainless A2/A4) against the operating environment.

• Installation torque guidance requested for vibrating-shaft applications.

• Shaft reuse plans confirmed — cone point marks the shaft more permanently than cup point.

Set screws are tiny, and point damage ruins them, so small-parts boxes within master cartons are the norm. Point type should be printed on every box.

With several million pieces per container, an accurate packing list by size and point type is important for receiving counts.

What is a grub screw?

Another name for a headless socket set screw that locks a component onto a shaft.

Which point should I choose?

Cup for repeatable removal, cone for permanent high hold, flat for finished or hardened shafts, dog point where a locating hole exists.

Why do set screws slip?

Usually insufficient torque or vibration; the point relies on friction and indentation alone.

Send these details with your enquiry and the first quote will be accurate, without a round of follow-up questions:

• Point type (cup, cone, flat, dog)

• Standard (DIN 913–916)

• Thread size and length

• Material (alloy or stainless)

• Shaft hardness and reuse plans

• Quantity

If any item is unknown, say so. We will suggest a suitable option and mark it clearly in the quotation for you to approve.

We confirm point type and size before production, form and harden points for wear resistance where required, and verify point geometry against the relevant DIN standard — tell us whether your shaft-locking application needs repeatable or permanent holding power and we'll recommend the right point type.