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 Screw, Stainless Steel Small Screw
Materials:Stainless Steel
Surface treatment:Plain
Head Type:Cap Head
Drive:Torx six-lobe socket, punched in the head face
Thread:Machine thread, rolled 60 degrees, full to the head bearing face
Point:Blunt end with a small chamfer; no taper, no drill point
Forming:Single-die heading with socket punch, thread rolling, cleaning and passivation, sorting
Size:M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M14
Number:78
We manufacture torx cap screws in the small sizes: a cylindrical cap head with a six-lobe star socket, a full machine thread and a blunt chamfered end, in plain stainless steel. Head, socket size and depth, thread and length are taken from your drawing.
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.
A torx cap screw is a cap head machine screw driven with a six-lobe star socket, and the recorded part on this page is the small-size version: stainless steel, plain finish, a full machine thread and a blunt end. It is quoted from M1 to M14 with Number 78.
Cap head. A short cylinder with a flat top and a full flat bearing face. On the small sizes it is still the widest bearing area available in a cylindrical head, which is why it is used where a tiny screw has to hold a plate without dishing it.
Star socket. Six curved lobes for a matching star bit. At M2 and M3 a hexagon key is the weakest part of the joint — its corners round the head first — and the star socket is what makes a small torx cap screw usable at torque.
Full machine thread. The thread runs from under the head to the end, so the whole length below the head engages. On a small screw in a thin plate, that is the difference between two turns of engagement and four.
Blunt end. A machine screw end with a small chamfer. It goes into a tapped hole, and the chamfer is what lets the first thread enter without catching on the lead-in.
Plain stainless. The alloy protects the part, so the socket is bare alloy and takes the bit at its formed size. On a small head that matters: a coating a few microns thick is a real fraction of the socket.
The cap head and the star socket are formed in one heading stroke. On the small sizes the wall between the socket and the outside of the head is only a few tenths of a millimetre, so the socket is punched rather than cut, and the punch is what sets both the lobe form and the depth.
The thread is rolled from under the head to the end. There is no plain shank, so every millimetre below the head is engagement — which is the right choice for a small torx cap screw that goes into a tapped hole or a nut rather than through a stack.
The end is blunt with a small chamfer, cut after rolling. A chamfer that is too small catches on the lead-in of a small tapped hole; one that is too large loses a thread of engagement, which on an M2 screw matters.
Cleaning and passivation follow. Because the finish is plain, nothing is added to the thread or the socket, so the part that gauges is the part that ships — and on small sizes that is the only way to keep the drive consistent.
The small end of the range is where the process is hardest. An M1.6 or M2 cap head has very little material around the socket, and the heading die and the punch have to be made for that size rather than scaled down from a larger one.
The family is quoted from M1 to M14, with M1, M2, M3, M4, M5, M6, M7, M8, M9, M10 and M14 in the recorded range. Custom lengths up to 2,000 mm are subject to DFM review after drawing submission; the practical centre of gravity for a torx cap screw is the small end, where the socket is the limiting feature.
| Item | How it is defined | What we control |
|---|---|---|
| Thread | Metric machine thread, rolled, full length | Gauged per batch |
| Head | Cap head, flat top, chamfered edge | Diameter and height on the projector |
| Socket | Torx six-lobe, sized to the thread | Checked with the production bit |
| Socket depth | Set against the head height | Checked on the section |
| End | Blunt with a small chamfer | Checked on the first article |
| Length | From under the head to the end | Measured on the shop plate |
The head height is the number that decides the counterbore, and on a small torx cap screw it is also what limits the socket. A head that is too shallow cannot carry a deep socket, and a socket that is too shallow rounds the lobes the first time the screw is driven hard.
The head diameter is what covers the hole. On small sizes the margin is tight: a head a size small can drop through an oversized clearance hole, and on a plate that has been drilled by hand that happens more often than on a punched one.
A small cap head and a star socket are a natural pair, because at the small sizes the drive is the weakest link in the whole joint.
| Feature | What it gives | What it costs |
|---|---|---|
| Star socket | Torque without rounding at small sizes | Needs the matching star bit |
| Cap head | Widest flat bearing face in a cylinder head | Taller than a pan or countersunk head |
| Full thread | Engagement over the whole length | No plain shank to locate the screw |
| Plain stainless | No coating to fill a small socket | Galls against stainless |
| Blunt end | Stops at the thread end in a tapped hole | Cannot start in an unthreaded hole |
At M2 a hexagon socket is a hole with six sharp corners in a head a couple of millimetres across. A hex key that is slightly worn rounds those corners almost immediately, and once the head is round there is nothing left to grip. A star socket spreads the load along curved flanks, so the same head can be driven at the torque the joint needs.
The full thread is the other half of the small-size argument. A small screw in a thin plate has very little length to work with, and every millimetre of plain shank is engagement lost. On a torx cap screw used to hold a cover or a plate, the full thread is what makes the joint reliable at that size.
The recorded finish is plain stainless with no coating. On a small socket head that is not a cost decision but a functional one: a plated layer on a 1.5 mm socket is a measurable fraction of the fit, and the drive is the feature most likely to fail.
| Option | What it does | Effect on socket and thread | Typical use |
|---|---|---|---|
| Cleaned and passivated | Removes free iron after forming | No dimensional change | General and wet service |
| Bright passivated | Cleaner, brighter surface | No dimensional change | Instruments and appliances |
| Satin bead blast | Even matte face on the head | Edges softened slightly | Visible panels |
| Electropolished | Levels micro peaks | Very slight removal in the socket | Hygienic service |
| Dry film in the socket | Reduces galling between bit and socket | Film checked with the bit | Joints opened often |
Passivation is the only treatment that can be added to a small torx cap screw without re-checking the drive. It removes the embedded iron from heading and rolling and leaves the socket geometry untouched, which is why it is the default on a plain stainless part.
Anything that builds a film has to be checked with the bit afterwards. On the small sizes a star socket that is tight by a few microns will not take the bit to full depth, and a bit that sits high will mark the head before it drives anything.
Three assemblies where a small cap head has to take torque and hold a plate:
| Where it sits | The screw holds a board, a bracket or a heatsink in a housing where the head is small and the tapped hole is in a thin insert. |
| When it goes wrong | A cross recess cams out and damages a head that is only a couple of millimetres across, and a hex key rounds the socket. |
| Why it happens | The space is tight, the fixing is small, and the assembly is handled. |
| What we control | Socket checked with the production bit, head diameter and height on the projector. |
| Where it sits | The screw fixes a mount, a stop or a stage plate where the fixing is small, the setting has to hold and the head sits in a bore. |
| When it goes wrong | A head that is too tall fouls the next component, and a drive that slips moves the setting. |
| Why it happens | The assembly is precise, the head is recessed, and the fixing is adjusted during setup. |
| What we control | Socket and head height checked, thread gauged per batch. |
| Where it sits | The screw holds a small cover or a sensor mount on stainless equipment that is cleaned daily. |
| When it goes wrong | A plated socket fills with coating and traps residue, and a cross recess holds water in its corners. |
| Why it happens | The equipment is stainless, it is washed, and the fixing is small but visible. |
| What we control | Grade and passivation recorded, socket checked with the bit after any treatment. |
Four reasons that matter on a small star-socket cap head, each tied to what the drawing has to prove:
|
Socket and head reviewed together
The socket size, the socket depth and the head height are reviewed as one set, so a socket that would thin a small head is raised before the die is cut. Basis: Socket and head reviewed as one set. |
Head, socket and thread in one route
The cap head and the star socket are punched in one stroke, and the full machine thread is rolled to a blunt chamfered end. Basis: One route from wire to passivated screw. |
|
Socket and thread checked on the part
The socket is checked with the production bit and the thread is gauged per batch, both in the finished condition. Basis: First article driven with the production bit. |
First article to repeat production
Drawing revision, wire heat, die set and thread roll are fixed at the first article and used as the comparison for repeat orders. Basis: First article signed off before the batch is released. |
Shi Shi Tong forms these torx cap screws on a single-die header that upsets the cap head and punches the six-lobe socket in one stroke, then rolls the full machine thread to a blunt chamfered end. The parts are cleaned and passivated. The first part of every run is measured on the head and the socket, and driven with the production bit at the joint torque, before the batch continues.
|
|
At the small sizes the punch is the tool that decides the part. A worn punch leaves lobes that look right and let the bit rock, and a bit that rocks rounds a 1.5 mm socket on the first hard drive. That is why the socket is checked by driving rather than by looking, and why the punch is changed on that evidence rather than on a count.
What decides whether torx cap screws pass is the socket, the head, the thread and the surface. The inspection agreement covers those, and the criteria come from the drawing.
Head and socket on the projector |
Thread gauged per batch |
Hardness testing against the property class |
Salt-spray testing where the service requires it |
The socket is checked by driving the first article at the joint torque with the production bit and reading the lobes afterwards. On a small torx cap screw the damage starts as a polish mark on a flank rather than as a missing corner, and that mark is what the inspection looks for.
The head is checked for height and top chamfer. A small cap head with a sharp top edge cuts the hand and marks the bore, and on a stainless part that mark cannot be polished out after the batch is made.
Every shipment of torx cap screws is traceable to the wire it was made from. 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 material. The documents carry the drawing revision and the batch number, so the paperwork can be matched to the parts.
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 small cap head the first article is driven with the production bit, because the socket is what fails first and the failure is hidden inside a head only a couple of millimetres across. Buyers visit during the process to review samples and to see how the heads are formed.
|
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 header 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 |
A cap head machine screw driven with a six-lobe star socket. This page’s part is the small-size, full-thread version in stainless steel.
A hexagon key rounds the corners of a small socket almost immediately. A star socket spreads the load along curved flanks and keeps the head usable at torque.
No. It has a blunt end and a machine thread, so it goes into a tapped hole or a nut.
From under the head to the end. With a full machine thread the whole length is engagement once it is inside the tapped hole.
It can, against another stainless thread or a worn bit. A dry film in the socket or a different alloy pairing are the usual answers.
Thread size and pitch, head diameter and height, socket size and depth, length and datum, stainless grade and surface treatment.
How a torx cap screw project runs from drawing to repeat delivery:
|
1
Send the drawing or sample
|
→ |
2
Socket and head review
|
→ |
3
First article driven at joint torque
|
→ |
4
Batch production and repeat orders
|
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 thread size and pitch, head diameter and height, socket size and depth, length and datum, stainless grade and surface treatment.
|
Thread and pitch
|
Head diameter and height
|
Socket size and depth
|
|
Length and datum
|
Grade
|
Surface treatment
|
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
