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Email：sst@szsst88.com
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Address：Building 9, First Industrial Zone, Tantou Industrial City, Songgang Street, Baoan District, Shenzhen 518105, Guangdong, China
Type:Allen Head Cap Screw Self Tapping
Materials:Carbon Steel
Surface treatment:Nickel Plated
Head Type:Cap Head
Drive:Hexagon socket (Allen)
Thread:Self-tapping
Point:Flat, blunt
Forming:Single Die Heading
Size:M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M14
Number:397
We make allen head cap screws with a self-tapping thread in nickel plated carbon steel: a socket cap head, a hexagon drive and a flat forming point, quoted from M1 to M14. Socket depth, thread form, point and pilot hole come from your drawing, and the first article is driven at your joint torque.
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ISO 9001:2015 · Manufacturing since 1998 · 8,678+ customers · 89 countries and regions
Made to order – there is no stock catalogue. Each part is produced to your drawing, and production starts after drawing review and first-article approval.
These screws combine a socket head with a self-tapping thread: a cylindrical cap head with a hexagon socket, a flat thread-forming point and a machine-style thread, in nickel plated carbon steel, quoted from M1 to M14 with Number 397.
Socket cap head. A flat-topped cylinder with an internal hexagon and a flat bearing face, seated in a counterbore.
Self-tapping thread. A thread that forms its own thread in the material it enters, so no tapped hole is needed.
Flat point. A blunt forming end that starts in a drilled pilot rather than piercing.
Nickel plating. A bright barrier deposit over carbon steel, for visible indoor work.
Allen head cap screws with a self-tapping thread are used where the head has to sit in a counterbore and the far part cannot be tapped: castings, mouldings and soft fixtures where an insert would be another operation.
The socket head gives the driver something to hold while the self-tapping thread forms its own path.
An allen head cap screw with a self-tapping point is doing two things that usually live apart. The cap head is the head of a machine screw: it seats in a counterbore, bears on a machined face and is driven with a key at real torque. The thread is the thread of a self-tapping screw: it forms its own thread in the far material instead of running in a tapped hole.
Allen head cap screws of this type are used where the far part cannot be tapped. A casting, a moulding or a thin plate that would need an insert gets a drilled pilot instead, and the screw forms its thread on the way in. The cap head means the joint can still be driven hard and finished flush in a counterbore, which a pan or button head would not allow.
On allen head cap screws the drive matters more than on a plain machine screw. Forming a thread takes torque, and the torque arrives through a hexagon socket that does not cam out; a cross recess would climb out as the load rose and leave a damaged head halfway into a joint that cannot be disassembled easily. The key is part of the tooling, and a worn one will round the socket at the torque the thread needs.
On allen head cap screws the flat point sets the way the thread starts. It is blunt, so it does not pierce; it locates in a drilled pilot and forms the thread without splitting a small boss. On a cap head the point is also protected by the head during handling, which on small self-tapping screws matters more than it sounds.
Nickel plating keeps the socket and the head presentable. It is thin enough that the hexagon still seats a key, and bright enough that a cap head in a counterbore looks like a finished detail rather than a repair.
The recorded range is M1 to M14, with lengths made to the drawing. Custom lengths up to 2,000 mm are subject to DFM review after drawing submission. For an allen head cap screw of this type the quotation carries head diameter and height, socket size and depth, overall length, thread form, point and the pilot hole.
| Item | How it is defined | What we control |
|---|---|---|
| Head | Socket cap head | Head diameter, height and face flatness |
| Socket | Internal hexagon | Across flats, depth and corners |
| Thread | Self-tapping | Thread form, length and crest condition |
| Point | Flat, blunt | Point diameter and squareness |
| Material | Carbon steel | Grade and heat number on the certificate |
| Finish | Nickel plated | Thickness and socket fit |
| Pilot hole | In the far part | Diameter advised per material |
Socket depth is quoted with the head height, because the socket is what limits the torque and the torque is what forms the thread.
Pilot hole diameter belongs on the assembly drawing. The screw cannot compensate for a hole that is too small or too large, and the right size depends on the material being formed.
Three features define the part: the socket, the forming thread and the flat bearing face. The first delivers the torque, the second removes the tapped hole, and the third spreads the clamp in the counterbore.
| Feature | What it gives | What it costs |
|---|---|---|
| Socket drive | Torque without cam-out | Needs the exact key size |
| Self-tapping thread | No tapped hole in the far part | Pilot hole must be right |
| Cap head face | Full ring of contact in a counterbore | Counterbore must be flat and deep enough |
| Nickel plating | Bright barrier finish indoors | A scratch becomes a rust point |
| Flat point | Starts in a pilot without piercing | Needs a drilled hole to locate |
On allen head cap screws the socket is the reason the part can be tightened. A self-tapping thread resists as it forms, and a drive that slips under that resistance leaves a joint half made; six flats under a key keep going.
On allen head cap screws the counterbore is the reason the fixing can be hidden. A cap head sits below the surface on a machined face, so the fixing is out of the way while the head still spreads the clamp over its full diameter.
The recorded finish is nickel plating over carbon steel. It is a barrier deposit, bright and hard, and on a socket cap head it has to be thin: the socket is what the key engages, and a deposit that narrows it is a deposit that shortens the drive.
| Option | How it protects | Effect on socket and thread | Typical use |
|---|---|---|---|
| Nickel plated | Barrier deposit, bright | Socket narrowed; re-checked | Visible machine assemblies |
| Zinc plated | Sacrificial zinc | Thin build; socket re-checked | General indoor work |
| Black oxide | Conversion film, oiled | No measurable build | Internal mechanisms |
| Black zinc plated | Sacrificial zinc, dark | Thin build; wear visible | Dark housings |
| Stainless alternative | Passive film, no build | Socket and thread as made | Wet and food service |
Where allen head cap screws work in a wet joint, stainless is the specification and the socket is the reason: a rusted socket cannot be re-entered with a key, and a self-tapping screw that will not turn has to be drilled out.
Where the part is visible and dry, nickel is the best of the inexpensive finishes; where the joint is hidden, zinc does the same job for less.
Three assemblies where an allen head cap screw with a self-tapping thread is the fixing:
| Where it sits | The screw forms its thread in a drilled boss on a casting or a moulding where tapping would need another operation. |
| When it goes wrong | A pilot hole that is too small splits the boss, and one that is too large never holds. |
| Why it happens | The far part is soft, there is no tapped hole, and the head must sit below the surface. |
| What we control | Pilot hole agreed; first article driven into a sample part. |
| Where it sits | The screw holds a guard in a counterbore where the head must be flush and the joint is assembled without a tapped hole behind. |
| When it goes wrong | A drive that cams out rounds the socket, and the guard cannot be removed. |
| Why it happens | The joint is tight, the far part is a sheet or casting, and the drive is a key. |
| What we control | Socket depth and thread checked; first article tightened. |
| Where it sits | The screw forms its thread in an aluminium or plastic fixture where a thread insert would be slower to fit. |
| When it goes wrong | A thread that strips in the soft fixture leaves nothing to rebuild. |
| Why it happens | The fixture is soft, it is rebuilt often, and the head is recessed. |
| What we control | Pilot hole and thread form agreed; first article driven. |
Four reasons that matter on a socket-head forming screw, each tied to what the drawing has to prove:
|
Socket and point agreed
Socket depth, thread form, point and pilot hole are agreed as a set, because on these screws the drive has to form the thread. Basis: Socket and point agreed. |
Headed, threaded, plated in one route
The cap head and hexagon are formed, the self-tapping thread rolled and the flat point cut before nickel plating. Basis: One route from wire to plated screw. |
|
Socket driven at torque
The first article is driven with the production key at the joint torque, because a shallow socket rounds at exactly the load the thread needs. Basis: First article driven at torque. |
Pilot hole recorded
The pilot hole and the driving torque are recorded, so a repeat order forms the same thread in the same material. Basis: Pilot hole and torque recorded. |
Shi Shi Tong forms these screws on single-die headers that form the cylinder and cut the hexagon, rolls the self-tapping thread and cuts the flat point before nickel plating. The first part of every run is measured on head diameter and height, socket depth, thread and point before the batch continues.
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A self-tapping thread on a cap head is a compromise between two shapes. The thread has to be coarse enough to form in soft material, and the head has to stay a cylinder with a socket in it; a roll that runs slightly long leaves the first thread too close to the bearing face, and the screw then cuts a burr on the face it is meant to seat on.
What decides whether these screws pass is the socket, the thread, the point and the head. The inspection agreement covers those, and the criteria come from the drawing.
Head and point on the projector |
Thread form checked |
Hardness checked on the wire |
Coating proved by salt spray |
The socket is checked for across flats and depth, the thread for form and length, and the point for diameter and squareness. The head is measured for diameter, height and face flatness, and the coating for thickness inside the socket.
The first article is driven into the customer material with the production key and the driving torque recorded. A screw that measures correctly and rounds its socket at that torque is a part that fails, and only the drive shows it.
Every shipment of these screws is traceable to the wire it was made from and to the plating batch. The grade and heat number are recorded on the material certificate supplied with the parts, and the inspection records follow the criteria agreed on the drawing.
ISO 9001:2015 |
RoHS test report |
Registered trademark |
Patent: security screw and driver |
With each batch we supply the material certificate, the inspection record for the criteria on the drawing and, where it is listed, the third-party report for the coating. The documents carry the drawing revision and the batch number, so a repeat order keeps the same socket and thread form.
More than 8,678 customers in 89 countries and regions have ordered from Shi Shi Tong; 87% of orders come from repeat customers and 56% through referrals. Most projects follow the same route: drawing review, first-article approval, then batches checked against that sample. On a socket-head forming screw the first article is driven into the customer part at the joint torque, because the thread and the socket are both proved there. Buyers visit during the process to review samples.
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8,678+
customers served
|
87%
of orders from repeat customers
|
56%
of orders through referrals
|
89
countries and regions shipped to
|
Buyers and quality engineers visit for sample review, process discussion and supplier audits; the visit is arranged around production so the headers and the plating line can be seen on the day the parts run.
Customer group visit – sample review |
Customer group visit – process discussion |
Customer group visit – factory tour |
Customer visit – project kick-off |
Danish customer – drawing review |
Industry exhibition – meeting customers |
Forming a thread takes torque, and a socket delivers it without cam-out; a cross would climb out and damage the head.
Yes. The flat point starts in a drilled pilot and forms the thread; without one it will not start cleanly.
A few times in plastic or soft metal. Each drive re-forms the thread, and the hold falls with every repeat.
Enough depth for the head and a flat face, so the head seats on its bearing face.
It narrows it slightly; the socket is checked after plating and the key must be the right size.
Head diameter and height, socket size and depth, thread form, point, overall length, grade and finish.
How an allen head cap screw project runs from drawing to repeat delivery:
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1
Send the drawing and the material it enters
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→ |
2
Socket, thread form and pilot hole agreed
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→ |
3
First article driven at the joint torque
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→ |
4
Batch production and repeat orders
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Each step is confirmed with you before the next one starts; the drawing revision from the first article is what repeat orders are checked against.
For a quotation, send the drawing with the head diameter and height, socket size and depth, thread form, point, overall length, grade and finish.
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Head diameter
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Socket size
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Thread form
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Point
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Overall length
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Finish
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Sending a drawing? The form below does not take attachments. Email the PDF, DXF or STEP file to sst@szsst88.com with the part name and quantity in the subject line – the drawing is reviewed and a quotation follows.
+86 13143444311
sst@szsst88.com
