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:Small Screw Manufacturers, Micro Screw Manufacturers
Materials:Stainless Steel
Surface treatment:Plain + Teflon Paste
Head Type:Low Profile Head
Drive:Phillips cross recess
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:872
We make micro screws in plain A2 stainless with a low flat head, a Phillips recess and a dry Teflon film on the thread, quoting them from M1 to M3. Head and recess, thread and the coating band come from your drawing, and the first article is driven at your torque setting.
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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.
Micro screws are machine screws at the small end of the range, from M1 to about M3, used in instruments, electronics and small mechanisms. The part recorded here is a stainless steel micro screw with a low flat head, a Phillips recess and a dry Teflon coating on the thread, quoted from M1 to M10 with Number 872.
Small sizes. M1 to M3 is where a screw head is a couple of millimetres across and a bit is a fraction of a finger.
Low profile head. A thin flat head that sits close to the surface for a cover or a bracket.
Phillips recess. Four tapered arms driven with a small cross-tip bit.
Teflon paste. A dry film applied to the thread that evens out friction and reduces galling.
Plain stainless. A2 grade, passivated, with the coating only on the thread where it is needed.
Micro screws are used in instruments, optical mounts, wearables, medical devices and small appliances, where the joint is small, the material is thin and the assembly is done with a torque-controlled driver rather than by feel.
On a large screw, friction is a correction to the torque-preload calculation. On micro screws it is most of the answer. The engaged thread length is small, the bearing area is small, and the difference between a dry stainless thread and a slightly lubricated one can change the clamp at a given torque by a large proportion.
That variability is what a dry Teflon film removes. The coating sits on the thread as a thin, low-friction layer, so the first assembly and the fifth feel the same, and two screws from the same box behave alike. Without it, tiny stainless screws vary: some drive smoothly, some gall partway, and a driver set to a single torque produces joints that are loose in one place and seized in another.
The head is the second constraint. A low flat head has little height, so the recess is shallow, and at M1.6 a worn bit is enough to round the cross. The low head is chosen when the cover above it leaves no room; where there is room, a pan or a cheese head gives the recess more depth and the assembly more margin.
Handling is the third. Micro screws are lost more often than they are broken: they stick to tools, drop into assemblies and jam feeders. The coating helps here too, because a dry film is cleaner than oil and does not attract dust, but the real answer is packaging and pick-up tooling, not the screw itself.
What the combination gives is repeatability at a scale where nothing is over-engineered. A micro screw is not a small version of an M6 joint; it is a fastener whose behaviour is dominated by friction, tolerance and handling, and the dry film is what makes the first of those manageable.
The recorded range is M1 to M10, with the micro sizes from 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 micro screws the quotation carries head diameter and height, recess size, thread, the coating and its position, and overall length.
| Item | How it is defined | What we control |
|---|---|---|
| Head | Low profile, flat top | Diameter, height and bearing face flatness |
| Recess | Phillips, PH size per diameter | Arm depth and floor thickness |
| Thread | Machine thread | Pitch, length and start position |
| Coat | Dry Teflon film on the thread | Coverage band and dry film weight |
| Length | Overall, head included | Length tolerance and thread start |
| Material | A2 stainless | Grade and heat number on the certificate |
The coating band is quoted like a patch position: the part of the thread that engages in the joint, not the whole screw. A film that runs onto the bearing face changes the seat, and one that stops short of the engaged threads does nothing.
Head height is the number that decides how much recess there is to work with. On a micro screw the difference between a 0.6 mm and a 0.8 mm head is the difference between a recess that survives ten assemblies and one that survives two.
Four features define this family, and each one carries a consequence:
| Feature | What it gives | What it costs |
|---|---|---|
| Micro sizes | Fits instruments and electronics | Little material around the recess |
| Dry Teflon film | Consistent friction; less galling | Wears off after a few assemblies |
| Low head | Fits under a cover | Shallow recess; limited torque |
| Machine thread | Repeatable joint in an insert | Needs a tapped hole or a nut |
| Plain stainless | No coating to flake in a device | Softer than the bit; galls without film |
The film is the feature that makes the rest work at this scale. It evens out the friction so the same torque gives the same clamp, and it reduces the galling that seizes stainless threads in aluminium inserts.
What it does not do is lock the joint against vibration. A dry film is a friction control, not a thread-locking device; where the joint must resist vibration, a nylon patch or a chemical locking compound is the right answer, and the two are often confused.
The recorded finish is passivation on A2 stainless with a dry Teflon film on the thread. Passivation keeps the head and the recess clean, and the film is applied only where friction matters, so the bearing face and the head top are left bare for the seat and for appearance.
| Option | How it protects | Effect on recess and thread | Typical use |
|---|---|---|---|
| A2, passivated, dry film | Passive film plus friction control | Thread coated; head bare | Instruments and electronics |
| A4, passivated, dry film | Passive film with molybdenum plus film | Thread coated; head bare | Medical and marine |
| A2, passivated | Passive film only | Recess and thread as formed | Static small joints |
| Steel, zinc plated | Sacrificial zinc | Build in lobes; re-checked | Low-cost indoor devices |
| Steel, black oxide | Conversion film, oiled | No measurable build | Optical assemblies |
Where the device is cleaned or sterilised, the film has to be one that survives the process; where it is not, a plain passivated screw is simpler and gives a drier surface than an oiled one.
Where a plated steel screw is used, the recess is gauged after plating. At M1.4 a zinc layer is a measurable fraction of the recess depth, and a recess that was in tolerance before plating can refuse the bit afterwards.
Three assemblies where the micro range is the only option:
| Where it sits | The screw sets a position that is adjusted, checked and reset, with a head that must stay below the housing line. |
| When it goes wrong | The recess rounds after a few adjustments and the setting cannot be held. |
| Why it happens | The screw is tiny, the joint is adjusted repeatedly, and the head is low. |
| What we control | Recess depth and coating band checked; first article adjusted and locked. |
| Where it sits | The screw closes a housing where the thread goes into a moulded or pressed insert and nothing may flake inside. |
| When it goes wrong | The thread galls in the insert and the screw seizes partway in. |
| Why it happens | The joint is small, the insert is aluminium or plastic, and the drive is a bit. |
| What we control | Coating coverage checked; first article assembled and reopened. |
| Where it sits | The screw holds a sub-assembly that is cleaned between uses and must not corrode or shed particles. |
| When it goes wrong | A plated screw sheds its layer into the device during cleaning. |
| Why it happens | The joint is washed, the part is stainless, and the head sits low. |
| What we control | Grade and coating confirmed; first article cleaned as the process requires. |
Four reasons that matter at this scale, each tied to something the drawing has to prove:
|
Coating band agreed
The dry film band, the engaged thread length and the head height are agreed as a set, because friction and recess depth are what the joint depends on. Basis: Coating band agreed. |
Headed, threaded and coated in one route
The head and recess are formed, the thread rolled, and the film applied to the defined band and dried. Basis: One route from wire to coated screw. |
|
Recess and friction checked
The recess is proved with the production bit and the film is checked by assembly into a gauge thread, because both change how the screw drives. Basis: Recess and friction checked. |
First article driven at your torque
The first article is driven at the customer torque setting, because at this size the usable window between loose and seized is narrow. Basis: First article driven at line torque. |
Micro screws are headed on single-die machines set up for small work, rolled with the thread and passivated, and then the dry film is applied over the band the drawing defines and dried before packing. The first part of every run is measured on head, recess, thread and coating band.
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At M1 to M3 the forming stroke is the whole part in one hit, and the recess punch is small enough that wear shows as a change in recess depth before it shows in any other dimension. That is why the punch is checked at the start of every run rather than on a schedule.
Applying the film is a controlled step rather than a dip. The band is masked so the bearing face stays clear, the film is applied thinly and evenly, and the parts are dried so it bonds instead of smearing. A film that is too heavy fills the thread and changes the fit; one that is too light does nothing.
What decides whether micro screws pass is the head, the recess, the thread and the film. The inspection agreement covers those, and the criteria come from the drawing.
Head and recess on the projector |
Thread and film checked |
Core hardness checked |
Salt-spray testing of the grade |
The recess is measured and then proved with the production bit, because at this size a recess can pass measurement and still refuse a worn bit. The film is checked by running a sample into a gauge thread and feeling the drag, which is the only practical measure of whether it will behave in assembly.
A sample from every batch is driven into the customer insert at the joint torque and removed. That cycle is what shows whether the film is doing its job: a coated screw should run in smoothly and come out without seizing.
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, where the coating is specified, its data sheet. The documents carry the drawing revision and the batch number, so a repeat order keeps the same recess 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 micro screws the first article is driven at the customer’s torque setting, because the usable window at this size 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 |
It evens out friction on the thread so a set torque gives a consistent clamp, and it reduces galling. It is friction control, not a locking device.
A few assembly cycles. Where the joint is opened often, a nylon patch or a locking compound is the better choice.
To fit under a cover. The cost is a shallow recess, which limits how many assemblies the drive survives.
The PH size for the diameter. A worn bit rounds a micro recess quickly, so bits are replaced rather than re-used.
They can, but a torque-controlled driver is what makes the joint repeatable at this size.
Head diameter and height, PH size, thread pitch, the coating band, and overall length.
How a micro screw project runs from drawing to repeat delivery:
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1
Send the drawing and the insert
|
→ |
2
Recess and coating band agreed
|
→ |
3
First article driven at your torque
|
→ |
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, PH size, thread pitch, the coating band and overall length.
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Head size
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PH size
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Thread pitch
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|
Coating band
|
Length
|
Grade
|
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
