Tel：
+86 13143444311
Email：sst@szsst88.com
Fax：+0086-755-27322278
Address：Building 9, First Industrial Zone, Tantou Industrial City, Songgang Street, Baoan District, Shenzhen 518105, Guangdong, China
Type:Allen Screw, Socket Screw Manufacturers
Materials:Stainless Steel
Surface treatment:Teflon Paste
Head Type:Cap Head
Drive:Hexagon socket (Allen)
Thread:Machine thread
Coat:Dry Teflon film on thread
Point:Plain, chamfered
Forming:Single Die Heading
Size:M1 M2 M3 M4 M5 M6 M7 M8 M9 M10
Number:593
We make Allen screws in plain A2 stainless with a cap head, a hexagon socket and a dry Teflon film on the thread, quoting them from M1 to M3. Head and socket size, thread and the coating band come from your drawing, and the first article is driven at your torque setting.
Watch the factory video·Email sst@szsst88.com
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.
Allen screws are screws driven with a hexagon key: the drive is an internal hexagon, and the tool is an L-shaped or a T-handled key. The part recorded here is a stainless steel Allen screw with a cap head, a machine thread and a dry Teflon film, quoted from M1 to M10 with Number 593, in the small sizes where the key is barely wider than a hair.
Hexagon socket. Six flats cut into the head, driven with an Allen key of a matching across-flats size.
Cap head. A cylindrical head with a flat top, which gives the socket as much depth as the form allows.
Machine thread. A uniform thread for a tapped hole, a nut or an insert.
Dry Teflon film. A thin coating on the thread that evens out friction and reduces galling.
A2 stainless. Passivated and uncoated on the head, so the socket is as formed.
Allen screws are the default fastener in machinery at every scale, but they are most useful at the small end: an M1.6 cap head takes a 1.5 mm key and gives more torque per millimetre of head than any cross recess could, which is what makes instrument and electronics assembly possible.
For Allen screws at M1 to M3 the hexagon socket is measured in fractions of a millimetre across flats, and the key that fits it is thin enough to bend between two fingers. That changes the joint completely: the socket is the strongest drive available at this size, but it is also the feature that fails first, and the failure is usually the key twisting rather than the screw stripping.
On an Allen screw the socket depth is set by the head height, and on a cap head that is generous compared with a countersunk or button head. That is why cap heads dominate small machine assemblies: there is more room to cut a hexagon, so the key engages over a useful length and the drive can take the torque the thread needs.
What remains on Allen screws is friction. A small stainless screw in a small tapped hole has a large surface-to-volume ratio, and the friction in the thread can vary enough between parts that a torque setting produces joints that are loose and joints that are seized. A dry film on the thread evens that out, so the setting means something from the first screw to the thousandth.
On Allen screws the film is also a light anti-loosening measure, though not a strong one. It raises friction slightly and keeps it stable, which helps a joint that sees mild vibration; for a joint that must not move, a nylon patch or a chemical locker is the correct answer, and the two are often confused because both are described as a coating on the thread.
Stainless decides how the joint ages on Allen screws. There is no plating to wear at the socket or to fill the thread, so the fit is the fit for the life of the part; but stainless galls, and on a small screw galling is the failure that ruins a joint, because there is no material to spare for rework.
The recorded range is M1 to M10, with the small sizes M1 to M3 being the working range of this page. Custom lengths up to 2,000 mm are subject to DFM review after drawing submission. For Allen screws the quotation carries head diameter and height, socket across flats and depth, thread pitch, the coating band and the overall length.
| Item | How it is defined | What we control |
|---|---|---|
| Head | Cap head, cylindrical | Diameter, height and top edge |
| Socket | Hexagon, across flats | Across flats, depth and corner condition |
| Thread | Machine thread | Pitch, length and start position |
| Coat | Dry Teflon film on the thread | Coverage band and film weight |
| Length | Overall, head included | Length tolerance and thread start |
| Material | A2 stainless | Grade and heat number on the certificate |
Across flats belongs on the drawing as a key size. At this scale the difference between one key size and the next is small enough that an operator will try to make the wrong one fit, and a key that is a size small reams the hexagon rather than turning the screw.
Socket depth is quoted with head height. A socket that is a few hundredths too deep leaves the walls thin and the head cracks at the corners; one that is too shallow lets the key sit high and load the top edge only.
Four features define small Allen screws, and each one is a trade:
| Feature | What it gives | What it costs |
|---|---|---|
| Hexagon socket | Highest torque per head size | Key size must match exactly |
| Cap head | Depth for the socket | Needs clearance around and above |
| Dry film | Stable friction; less galling | Not a strong locking device |
| Machine thread | Repeatable preload | Needs a tapped hole or insert |
| Small sizes | Fits instruments and electronics | Key is fragile; socket is shallow |
The torque advantage is the reason Allen screws use this drive. A hexagon key engages six flats over a usable length, so the same head diameter that carries a fraction of a newton metre through a cross recess can carry several times that through a socket.
The cost on Allen screws is tool discipline. A small key that has been twisted, or one that is a size out, damages the socket in a way that cannot be corrected; and because the head is small, there is nothing to grip once the hexagon is gone.
The recorded finish is passivation with a dry Teflon film on the thread. The head and the socket are left bare, because a coating there would change the key fit; the film goes where it changes the assembly, which is the engaged thread.
| Option | How it protects | Effect on socket and thread | Typical use |
|---|---|---|---|
| A2, passivated, dry film | Passive film plus friction control | Socket as formed; thread coated | Instruments and machinery |
| A4, passivated, dry film | Passive film with molybdenum plus film | Socket as formed; thread coated | Medical and marine |
| A2, passivated | Passive film only | Socket and thread as formed | Static small joints |
| Steel, black oxide | Conversion film, oiled | No measurable build | Tooling and fixtures |
| Steel, zinc plated | Sacrificial zinc | Build in socket; re-checked | General indoor work |
Where the joint is adjusted repeatedly, the film is what keeps the fifth adjustment feeling like the first. Where the joint must not move at all, a locking patch is added on top of, or instead of, the plain film.
Where a plated steel screw is used, the socket is gauged after plating. At M2 a zinc layer is a measurable fraction of the across-flats, and a socket that was in tolerance before plating can refuse the key afterwards.
Three assemblies where a small socket drive is the only workable option:
| Where it sits | The screw sets a position that is adjusted, checked and locked, in a space too small for an external drive. |
| When it goes wrong | The socket rounds on the second adjustment and the setting cannot be held. |
| Why it happens | The screw is small, the joint is adjusted, and the key must come in from above. |
| What we control | Socket proved with the production key; first article adjusted and locked. |
| Where it sits | The screw closes a housing or fixes a bracket where the head has to be small and the joint must take a defined torque. |
| When it goes wrong | The thread galls in an aluminium insert and the screw seizes partway in. |
| Why it happens | The joint is small, the insert is soft, and the drive is internal. |
| What we control | Coating band and socket checked; first article assembled and reopened. |
| Where it sits | The screw holds a die or an insert where the head sits in a pocket and the joint is opened for maintenance. |
| When it goes wrong | The socket wears until the insert cannot be removed without damaging the tool. |
| Why it happens | The joint is loaded, the access is from the top, and removal matters as much as assembly. |
| What we control | Socket and thread checked; first article assembled and released. |
Four reasons that matter on a small socket screw, each tied to something the drawing has to prove:
|
Socket and key size agreed
Across flats, socket depth and head height are agreed as a set, because at small sizes the key and the socket must match exactly. Basis: Socket and key size agreed. |
Headed, socketed and coated in one route
The head and hexagon are formed in one stroke, the thread rolled, and the film applied to the engaged band. Basis: One route from wire to coated screw. |
|
Socket proved with the key
The socket is gauged and proved with the production key at the joint torque, because a shallow hexagon passes measurement and fails a key. Basis: Socket proved with the key. |
First article at your torque
The first article is driven at the customer torque setting, because the window between loose and seized is narrow at this size. Basis: First article driven at line torque. |
These screws are headed on single-die machines that form the cap head and cut the hexagon socket in one stroke, then rolled with the machine thread and passivated before the dry film is applied to the thread band. The first part of every run is measured on head, socket, thread and length.
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At M1.6 the socket punch is a few tenths of a millimetre across, and its wear shows as a change in socket depth before it shows anywhere else. The punch is checked at the start of every run rather than on a count, because a batch made with a worn punch passes a sample check and fails in assembly.
Applying the film is a controlled step rather than a dip: the band is defined, the film is laid thinly and dried so it bonds, and the bearing face is left clear. A film that is too heavy fills the engaged threads and changes the fit, and one that is too light does nothing at all.
What decides whether Allen screws pass is the head, the socket, the thread and the film. The inspection agreement covers those, and the criteria come from the drawing.
Head and socket on the projector |
Thread and start checked |
Core hardness checked |
Salt-spray testing of the grade |
Head diameter and height are measured on a projector, the socket is measured across flats and checked for depth, and then it is proved with the production key at the joint torque. At small sizes that last check is the one that matters, because a hexagon can measure correctly and still refuse a key that is slightly worn.
A sample from every batch is assembled into the customer insert and removed. That cycle shows both failures at once: a socket that rounds on removal, and a thread that galls on the way in.
Every batch is traceable to the wire it was made from and to the passivation and coating batches. The grade and heat number appear 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 shipment we supply the material certificate, the inspection record for the dimensions on the drawing and the coating data sheet. The documents carry the drawing revision and the batch number, so a repeat order keeps the same socket and the same film band.
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 Allen screws the first article is driven at the customer torque setting, because at small sizes the usable window is narrow. Buyers visit during the process to review samples.
|
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 coating 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 |
The across-flats size on the drawing. At M1 to M3 it is a fraction of a millimetre, and a key one size off reams the socket.
A worn or undersized key, or a torque above what the small head can take. The socket is the limiting feature at this size.
It evens out friction on the thread so a set torque gives a consistent clamp, and it reduces galling. It is not a strong lock.
Yes, with a lubricated or coated thread. Stainless in aluminium galls without it.
A2 covers rain, A4 covers chlorides. With no coating on the head, the socket stays as formed.
Head diameter and height, socket across flats and depth, thread pitch, coating band and length.
How an Allen screw project runs from drawing to repeat delivery:
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1
Send the drawing and the insert
|
→ |
2
Socket size and thread agreed
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→ |
3
First article driven at your 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 across flats and depth, thread pitch, coating band and overall length.
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Head size
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Socket AF
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Socket depth
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Thread pitch
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Length
|
Coating
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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
