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:Torx Cap Head Screws
Materials:Stainless Steel
Surface treatment:Plain
Head Type:Cap head
Drive:Torx Recess
Thread:Machine Thread
Point:Blunt
Forming:Single Die Heading
Size:M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M14
Number:478
We make Torx cap head screws in passivated stainless with a tall head, a six-lobe recess and a machine thread, quoting them from M1 to M14. Recess size, head height, thread and joint torque come from your drawing, and the first article is driven with the bit your line will use.
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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.
Torx cap head screws are socket screws with a tall cylindrical head and a six-lobe star recess, made in passivated stainless and quoted in metric thread sizes. The head sits in a counterbore, the star drive transmits torque without climbing out, and the machine thread clamps the joint. This family is quoted from M1 to M14 with Number 478.
Cap head. A cylinder with a flat top and a full flat bearing face, designed to be tightened hard.
Torx recess. Six lobes with near-parallel flanks. The bit is carried on the walls, so the torque goes in without the driver lifting.
Machine thread. A rolled thread for a tapped hole or a nut, ending in a blunt chamfer.
Passivated stainless. Uncoated, so the recess is exactly as cut and the alloy does the protecting.
In use Torx cap head screws are specified where the joint has to reach a real preload and the drive must not be the part that gives way first.
A cap head exists to be tightened. Everything about it — the height, the flat bearing face, the deep socket — is there to let an assembler put a real preload into a joint without damaging the fastener. The drive is the interface where that effort enters, and a Torx cap head screw is the version where the interface stops being the limit.
Torx cap head screws work because the six lobes enclose the bit. A cross recess is designed to cam out, and a hexagon can round when the key is worn; a Torx bit sits in the walls and keeps its grip as the torque rises. That means the tightening stops being governed by the drive and starts being governed by the thread, the seat and the material — which is where a designer wants the limit to be.
On stainless, that shift matters more than on steel. A stainless cap screw has no property class to tell you what torque it will take, it galls against stainless, and its thread will usually strip before its head deforms. With a drive that does not slip, the assembler finds that thread limit directly, and the result is either a properly preloaded joint or a stripped one — with less room than usual in between.
The counterbore decides how much of that preload actually reaches the joint. The flat bearing face of a cap head has to sit on a flat, square seat; on a rough or as-cast surface the head contacts on one side, tilts as it is tightened and puts an eccentric load into the shank. With a drive that can reach high torque, that fault is amplified rather than absorbed.
The recess is also the part that has to survive service. A Torx socket holds its shape across many assemblies, which is why equipment that is opened and closed repeatedly ends up with Torx screws after the first redesign. On a stainless part, where the socket cannot be re-cut once it is damaged, that endurance is the practical difference between a screw that can be removed and one that has to be drilled.
The recorded range is M1 to M14, covering M1, M2, M3, M4, M5, M6, M7, M8, M9, M10 and M14. Custom lengths up to 2,000 mm are subject to DFM review after drawing submission. For Torx cap head screws the quotation carries head diameter and height, recess size and depth, the thread and the grade, because the recess size decides the bit and the head height decides the recess.
| Item | How it is defined | What we control |
|---|---|---|
| Head | Cap head, flat top | Head diameter and height |
| Recess | Torx, six-lobe star | Recess size and depth, bit fit |
| Thread | Machine thread | Pitch and length, gauged per batch |
| End | Blunt, chamfered | Chamfer cut, not deburred |
| Finish | Passivated stainless | Surface condition and film |
| Length | Under the head | Measured on the shop plate |
Recess size should be written on the drawing, because the Torx number does not follow the thread size automatically across manufacturers. A T20 in one range and a T25 in another can both be offered for the same thread, and the difference shows up as a line that has to stock two bit sizes for what looks like one screw.
Head height is the other number to fix. A shorter cap head carries a shallower recess and therefore less torque, and on a stainless screw, where the thread is the limit anyway, it is easy to fool yourself into thinking the head is the constraint. Writing both numbers down keeps the joint honest.
Three features define this part: the Torx recess, the flat bearing face and the stainless body. The first delivers the torque, the second puts it into the joint, and the third decides how much of it the material will accept.
| Feature | What it gives | What it costs |
|---|---|---|
| Torx recess | Drive that does not cam out | Exact bit required |
| Deep socket in a tall head | High torque available | Needs a counterbore |
| Flat bearing face | Full-area seat for preload | Tolerates nothing on an uneven surface |
| Stainless body | No coating to wear in the socket | Galls; no strength grade |
| Passivated finish | Socket as cut | Not a lubricant |
The absence of cam-out is the feature people notice last and rely on most. With a cross recess, the joint is protected from over-torque by the driver slipping; with Torx, nothing slips, so a torque wrench or a defined setting is what protects the joint. That is a better arrangement, but it has to be arranged.
The stainless body is what makes the part suitable for equipment that is washed or exposed. The socket is the most sheltered part of the screw and the most corrosion-prone, because water sits in it; a passivated stainless socket has nothing to rust there, which is the practical argument for the material even before the appearance of the head is considered.
The recorded finish is passivation with no coating. On a Torx cap head that is the only sensible finish: a coating would narrow the lobes, which are the drive, and it would wear off exactly where the bit presses. Passivation leaves the recess as cut and gives the alloy its corrosion resistance, with no measurable change to the geometry.
| Option | How it protects | Effect on recess | Typical use |
|---|---|---|---|
| A2 stainless, passivated | Passive chromium oxide film | Recess as cut | General outdoor and indoor |
| A4 stainless, passivated | Passive film with molybdenum | Recess as cut | Coastal and chemical |
| Steel, black oxide | Conversion film, oiled | No measurable build | Internal machine parts |
| Steel, zinc plated | Sacrificial zinc | A few microns; recess re-checked | Indoor general work |
| Steel, nickel plated | Barrier deposit, bright | Decorative; wears at the lobes | Visible hardware |
A steel Torx cap screw with a proper property class will take more preload than any stainless one, and where the joint is heavy and dry that is the right part. The stainless version is chosen for corrosion resistance, not for strength, and the two decisions should not be confused.
Where stainless is chosen, galling is the behaviour to plan for. A stainless Torx cap screw driven dry to a high torque can seize on the mating thread, and because the drive does not slip, the seizure shows up as effort rather than as a slip. A small amount of lubricant on the thread, or a different alloy for one of the two parts, keeps the joint predictable.
Three assemblies where Torx cap head screws are the fixing:
| Where it sits | The screw clamps a guard or a bracket where the joint is tightened to a preload and the socket has to stay clean and openable. |
| When it goes wrong | Water sitting in a steel socket rusts it shut, and a damaged socket cannot be re-cut on a stainless screw. |
| Why it happens | The joint is wet, it is serviced, and the head is in a counterbore. |
| What we control | Grade confirmed, recess driven with the production bit, passivation inspected. |
| Where it sits | The screw clamps a jaw or a plate at a defined torque where the head sits in a counterbore and the joint is set by measurement. |
| When it goes wrong | A seat that is not square tilts the head, and a short head limits the torque before the joint reaches its preload. |
| Why it happens | The preload is specified, the seat is machined, and the drive must not slip. |
| What we control | Seat flatness and recess depth checked, first article tightened to torque. |
| Where it sits | The screw holds a fitting where the head is buried, the environment is salt-laden and the fixing is opened rarely. |
| When it goes wrong | A hexagon key rounds in a corroded socket, and a plated screw rusts from inside the recess. |
| Why it happens | The joint is wet, the socket is sheltered from washing, and the tool is available. |
| What we control | A4 grade confirmed, recess and seat checked, salt-spray sample where required. |
Four reasons that matter on a star-driven cap head, each tied to what the drawing has to prove:
|
Recess size and torque agreed
The Torx number, the head height and the joint torque are confirmed together, because the recess size decides the bit and the head height decides the recess. Basis: Recess size and torque agreed. |
Head, recess and thread in one route
The cap head and the six-lobe recess are formed in the heading stroke, the thread is rolled and the parts are passivated in the same route. Basis: One route from wire to passivated screw. |
|
Driven with the exact bit
The first article is driven with the Torx bit that will be used on the line, because a recess that measures correctly can still refuse a worn bit. Basis: First article driven with the line bit. |
First article fixes the setting
The first article fixes the wire, the recess punch and the passivation; repeat orders are compared against that record. Basis: First article signed off before the batch is released. |
Shi Shi Tong forms these Torx cap head screws from stainless wire on single-die headers that form the tall head and cut the six-lobe recess in one stroke, rolls the machine thread to a blunt chamfered end and passivates the finished parts. The first part of every run is measured on the head and recess, driven with the production bit and entered into a thread gauge before the batch continues.
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The recess punch is the tool that decides the drive. Six lobes need a punch that stays sharp and stays concentric with the head; a worn punch leaves lobes that are shallow on one side, and a bit in that recess bears on three lobes instead of six. Because the drive is the point of the part, that wear is checked at the start of every run rather than left to the next batch.
What decides whether Torx cap head screws pass is the recess, the head, the thread and the alloy. The inspection agreement covers those, and the criteria come from the drawing.
Head and recess on the projector |
Thread gauged per batch |
Hardness checked on the wire |
Salt-spray testing of the grade |
The recess is checked for size, depth and lobe shape, then driven with the production bit at the joint torque. The head is checked for diameter, height and face flatness, since the flat face is what carries the preload into the counterbore; a face that is domed contacts on a ring and the joint is never as tight as the torque suggests.
The thread is gauged per batch and the alloy is confirmed on the certificate. A salt-spray sample is run where the environment asks for it; inside a Torx recess is where corrosion would matter most, because it is the one place on the screw that cannot be repaired.
Every shipment of Torx cap head screws is traceable to the wire it was made from and to the passivation 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 grade or the passivation. The documents carry the drawing revision and the batch number, so a repeat order is made to the same recess geometry that was approved.
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 screw the first article is driven with the line bit in the customer’s counterbore, because the fit at the drive and the seat are what the joint depends on. Buyers visit during the process to review samples and to see how the heads and recesses are formed.
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8,678+
customers served
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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 passivation 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 bit stays seated, so more torque reaches the joint and the socket lasts longer. The trade is that an exact bit has to be on hand.
Take the size the maker offers for that thread and write it on the drawing. It is not automatic across suppliers, and it decides which bit the line stocks.
The head needs a flat seat. A counterbore or a spot face is the usual way to provide one; a rough surface will tilt the head under torque.
On stainless, usually yes. There is no property class and the thread is the softer limit, so the torque is set from the thread rather than from the head.
A dry stainless socket can gall on the bit. A little lubricant on the thread, and a bit in good condition, keeps it predictable.
Head diameter and height, Torx recess size, thread size and length, the grade, and the torque the joint will use.
How a Torx cap head screw project runs from drawing to repeat delivery:
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1
Send the drawing and the counterbore
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→ |
2
Recess size, head height and torque agreed
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→ |
3
First article driven with your line bit
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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, the Torx recess size, the thread size and length, the grade and the torque the joint will use.
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Head diameter
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Head height
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Torx size
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Thread size
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Length
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Joint torque
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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
