Set Screw Types Selection Guide | Hebei Wotu Fastener Manufacturing Co., Ltd.
Set screw types are chosen by the way the screw grips a shaft, collar, gear, pulley, knob, or adjustment part. The main decision is not only thread size; the point style, drive style, material, and finish all affect holding force, surface damage, vibration resistance, and serviceability.
For a purchasing inquiry, the most useful starting point is the application: a permanent shaft lock, a removable positioning screw, a low-marking contact point, or an adjustment screw that will be moved repeatedly.
Brand: Hengzuan Surface: color zinc plated, can be customizedblue-white zinc plated Specifications: in stock 4.8/5.5 common wire diameter, rod length 16~125mm full range of specifications, supports nonstandard customized Packaging: 25kg cartons, whole wooden pallets, support neutral packaging, private-label customization
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Brand: Hengzuan Surface: screw color zinc plated, head color nylon protective cap, multiple colors available Specifications: Chinese national standard ST5.5, ST6.3 mainstream caliber, rod length 25mm~125mm full range of specifications in stock, supports nonstandard length customization, suitable for drilling steel sheet thickness 2~6mm Packaging: 25kg cartons, full pallets packed on wooden pallets, support neutral packaging, private-label customization
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Brand: Hengzuan Surface: Dacromet anti-corrosion coating Specifications: in stock ST5.5/ST6.3 mainstream caliber, rod length 50mm~150mm, extended full range of specifications, supports nonstandard extra long customized, suitable for drilling steel sheet thickness 2~6mm Packaging: 25kg export cartons, full pallets wrapped with film, supports neutral export packaging, private-label customization
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Brand: Hengzuan Surface: blue and white zinc plated, optional color zinc plated, black oxide treatment Specifications: Follow GB/T846-1985 Chinese national standard, in stock ST4.2/ST4.8/ST5.5 full range of specifications Packaging: 25kg export cartons, full pallets wrapped with film, supports neutral export packaging, private-label customization
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Brand: Hengzuan Surface: blue and white zinc plated Specifications: in stock 3.5/3.9/4.2 mainstream wire diameter, rod length 16mm~80mm full size range in stock, supports nonstandard length customization; fine/coarse tooth types are available Packaging: 25kg export cartons, full pallets wrapped with film, supports neutral export packaging, private-label customization
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Brand: Hengzuan Surface: blue and white zinc plated, optional color zinc plated, black oxide treatment Specifications: in stock ST3.5/ST4.2/ST4.8 mainstream specifications, rod length 16~50mm full size range, supports nonstandard length customization, suitable for drilling steel sheets 2~5mm Packaging: 25kg cartons, full pallets packed on wooden pallets, support neutral packaging, private-label customization
Read MoreSet screw selection criteria
Set screw selection should compare point geometry, drive access, thread form, material, coating, and the mating surface. The right choice depends on whether the screw must bite, locate, adjust, or hold without leaving heavy marks.
| Criterion | What To Check | Why It Matters | Buyer Tip |
|---|---|---|---|
| Tip style: cup, cone, flat, or dog point | Match the tip to the mating surface and inspect a drawing or sample. | A cup point grips a shaft, while a flat point reduces surface damage and a cone or dog point serves different locating or seating needs. | Ask, “Which point style is recommended for our shaft material, load, and acceptable surface marking?” |
| Thread size, pitch, and engagement length | Compare the specified thread with the tapped hole and confirm the required engagement length. | An incorrect pitch can damage the internal thread, while too little engagement can weaken retention and too much length can interfere with internal parts. | Provide the tapped-hole thread, available hole depth, and the required screw length for confirmation. |
| Drive type and access clearance | Check the drive recess against the installation tool and the space available around the screw. | Hex socket, slotted, and other drives differ in tool access, resistance to cam-out, and suitability for repeated adjustment. | Ask which drive gives reliable installation in the available clearance and whether a matching key or bit is required. |
| Screw material and surface finish | Compare the base material and finish with the mating component and exposure to moisture, chemicals, or heat. | Material and finish affect corrosion resistance, galling risk, strength, and the chance of staining or reacting with the assembly. | Describe the service environment and ask for the proposed material and finish, including any compatibility concerns. |
| Headless length and seating position | Measure the available tapped-hole depth and confirm how far the screw should sit below, flush with, or above the surface. | A headless set screw must provide enough thread engagement without protruding into moving parts or preventing the assembly from fitting. | Send the shaft or component dimensions and ask for a recommended length that leaves the intended seating position. |
The biggest practical difference between set screw types is the point. Cup point screws are common for strong holding on shafts because the edge bites into the mating surface. Flat point screws spread load and reduce marking, but usually give less bite. Cone point screws locate aggressively and can provide strong penetration, while dog point screws fit into a hole or slot for more controlled positioning.
Drive style matters too. Hex socket set screws are widely used where torque and tool access are important. Slotted types can suit simple adjustment but are easier to damage under higher torque. If the assembly is exposed to vibration, repeated adjustment, or corrosion, those conditions should influence the choice before the order quantity is discussed.
Start with the contact requirement. If the screw must lock a rotating part to a shaft, ask whether marking the shaft is acceptable. A cup or cone point may hold better, but it can damage the surface and make later repositioning harder. If the component must be removed without visible damage, a flat, oval, or soft-tipped contact may be more suitable.
Match the point to the mating feature. A dog point should align with a drilled hole, groove, or slot; otherwise it will not seat correctly. A flat point needs enough contact area to resist movement. A cone point should not be used casually on thin or soft parts where penetration could distort the assembly.
Check access before choosing the drive. Socket drives allow compact installation and better torque transfer in many mechanical assemblies, but the tool must fit straight into the screw. Slotted drives may be easier for light adjustment, yet they are more likely to cam out. If the screw sits deep inside a housing, confirm the wrench clearance and installation method.
Avoid ordering by thread diameter and length alone. Confirm thread standard, point type, drive type, material, finish, required locking method, and the surface it will bear against. For a quotation, send a drawing or sample reference if available, plus the application, mating material, expected adjustment frequency, and any corrosion or vibration concerns.
| Criteria | Importance | Description | Example Options |
|---|---|---|---|
| Point style | Usually the most important selection factor | The point determines how the screw contacts the mating part, including holding force, surface marking, and positioning accuracy. | Cup point for stronger bite on a shaft; flat point where lower marking is preferred; dog point for a matching hole or slot. |
| Surface damage tolerance | Critical when parts must be reused or repositioned | More aggressive points can improve grip but may leave indentations, burrs, or marks that affect later adjustment. | A pulley fixed permanently to a shaft may accept marking, while a visible adjustment knob may need a gentler contact point. |
| Drive access | Important for installation reliability | The drive must suit the available tool clearance and tightening method. Poor access can lead to stripped drives or inconsistent tightening. | A socket drive may fit a recessed mechanical assembly, while a slotted drive may be used for light manual adjustment. |
| Application function | Defines whether grip, location, or adjustment matters most | A screw used for locking a shaft has different needs from one used as a stop, locator, or repeat-adjustment part. | A collar on a rotating shaft may need bite, while a stop screw in a fixture may need repeatable contact. |
| Material and finish | Important when corrosion, wear, or appearance affects service life | Material and surface finish should match the working environment and the mating component, but they should not be chosen before the mechanical function is clear. | An indoor adjustment screw may have different finish needs than a fastener exposed to moisture or frequent handling. |
Related Options
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A cup point is often chosen for shaft locking because its rim can bite into the surface. A cone point can grip even more aggressively, but it may create deeper marking or indentation, so it is better for applications where permanent location is acceptable.
A flat point spreads contact more gently than a cup or cone point, so it is a common option where visible damage or burrs are a concern. The trade-off is usually lower resistance to slipping, especially on smooth round shafts under vibration or torque.
No. A dog point is meant to enter a hole, slot, or groove and provide controlled positioning or alignment. If the mating part does not have a matching feature, the dog point may not seat correctly and may perform worse than a cup or flat point.
Yes. A hex socket drive usually gives better torque transfer in compact mechanical assemblies, while a slotted drive may suit light adjustment but can be easier to damage. Tool access, installation depth, and expected tightening torque should be checked before ordering.
Send the thread size and length, point type, drive type, material or finish requirement, and the mating material. It also helps to state whether the screw will lock a rotating part, locate against a hole or groove, or be adjusted repeatedly.
Share the thread size or drawing, point style needed, mating material, and whether the screw is for locking, locating, or repeated adjustment. Also note any vibration, corrosion, or surface-marking limits.
