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 Socket Cap Screw
Materials:Stainless Steel
Surface treatment:Plain
Head Type:Cap Head
Drive:Torx six-lobe socket, punched in the head face
Shank:Plain unthreaded shank under the head, acting as a locating shoulder
Thread:Machine thread, rolled 60 degrees, lower section from the thread start to the end
Point:Blunt end with a small chamfer; no taper, no drill point
Forming:Single-die heading with socket punch, thread rolling on the lower section, cleaning and passivation, sorting
Size:M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M14
Number:597
We manufacture torx socket cap screws as partial-thread machine screws: a cap head with a six-lobe star socket, a plain locating shank and a rolled thread on the lower section, in plain stainless steel. Head, socket, shank, thread start 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 socket cap screw is a cap head screw driven with a six-lobe star socket, and the recorded part on this page is a partial-thread machine screw: a plain shank under the head and the thread on the lower section. It is stainless steel, cleaned and passivated, quoted from M1 to M14 with Number 597.
Cap head. A short cylinder with a flat top and a full flat bearing face, sized to sit down in a counterbore. The head is what carries the clamp load, and its width is why a cap head spreads load better than a pan head of the same thread.
Star socket. Six curved lobes for a matching star bit. There are no sharp internal corners in the drive, so the socket takes more torque before it deforms than a hexagon of the same size, and it does not cam out the way a cross does.
Partial thread. A plain cylindrical shank under the head, then the thread starts and runs to the end. The shank acts as a shoulder through a clearance hole; the thread clamps at the far end. The thread start is a joint dimension, not a detail.
Stainless, plain. The alloy protects the part, so the socket is bare alloy and takes the bit at its formed size. There is no coating to chip at the socket edges and no film to change the thread.
Machine screw. A blunt end and a rolled thread: this screw goes into a tapped hole or a nut. It does not cut its own thread, which is the difference between it and the self-tapping socket head screws in the same family.
The cap head and the star socket are formed in one heading stroke, so the socket stays concentric with the shank. On a cap head that concentricity is what keeps the bit driving along the axis instead of tipping the head against the counterbore wall.
The plain shank is turned or formed to the nominal diameter and left unthreaded. It is a fit, not a clearance: it passes the clearance hole and lets the clamped part sit square, and where the joint pivots it is the surface that wears rather than the thread.
The thread is rolled on the lower section, and the thread start is set by the rolls rather than trimmed afterwards. That is why a torx socket cap screw with the wrong shank length cannot be corrected later: the position of the first full thread is fixed at the roll.
The end is blunt with a small chamfer. There is no point, because the hole is already tapped, and the chamfer is what lets the first thread enter without catching on the lead-in of the hole.
Cleaning and passivation close the route, and because the finish is plain, the dimensions that ship are the ones that were gauged.
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; on a torx socket cap screw the overall length, the plain shank and the thread length are three numbers that all belong on the drawing.
| Item | How it is defined | What we control |
|---|---|---|
| Thread | Metric machine thread, rolled, lower section | 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 |
| Plain shank | Nominal diameter, unthreaded | Measured with a micrometer |
| Thread start | Position where the thread begins | Measured from under the head |
| Length | From under the head to the end | Measured on the shop plate |
The thread start is the dimension that decides the joint. Too high, and the thread grips the clearance hole and clamps the wrong layer; too low, and there is too little thread in the tapped hole to carry the load. On a partial-thread screw the position is quoted from under the head, with the overall length alongside so the numbers cross-check.
The head height is what decides the counterbore. A cap head is taller than a pan head of the same thread, so a counterbore designed for a pan head will not take it — and on a machined face a head standing proud is obvious from a distance.
The two features that matter on this part are the drive and the plain shank, and each of them answers a different question about the joint.
| Feature | What it gives | What it costs |
|---|---|---|
| Torx socket | High torque without cam-out or corner rounding | Needs a star bit rather than a hex key |
| Cap head | Full flat bearing face, sits in a counterbore | Taller than a pan or countersunk head |
| Plain shank | Shoulder for a clearance hole or a pivot | No thread in that length |
| Partial thread | Thread only where the tapped hole is | Thread start must be quoted |
| Plain stainless | No coating to chip or fill the socket | Galls against stainless |
The socket is chosen where the joint has to be tightened hard and the head is small. A hexagon socket works on a large head, but at M2 and M3 the key is tiny and the corners round first; a star socket spreads the load along curved flanks and keeps the head usable through repeated assembly.
The plain shank is chosen where the joint has to locate before it clamps. A screw threaded to the head scores the clearance hole as it is driven and cannot let the clamped part sit on a shoulder; on a torx socket cap screw the shank does both jobs, at the cost of a length that carries no thread.
Together they suit a joint that is set once and then opened occasionally: the shank locates the parts, the thread clamps them, and the socket survives being re-tightened without rounding.
The recorded finish is plain stainless, cleaned and passivated. On a socket head that is the practical default: the socket is the feature that fails first, and any coating that builds inside it changes the fit of the bit.
| Option | What it does | Effect on socket and shank | Typical use |
|---|---|---|---|
| Cleaned and passivated | Removes free iron after forming | No dimensional change | General and wet service |
| Satin bead blast | Even matte face on the head | Edges softened slightly | Visible machined assemblies |
| Bright passivated | Cleaner, brighter surface | No dimensional change | Instruments and appliances |
| Electropolished | Levels micro peaks, stronger passive layer | Very slight removal in the socket | Hygienic and chemical service |
| Dry film on the thread | Reduces galling in stainless joints | Film checked in the socket | Joints opened often |
Passivation can be added without changing the part: it removes the embedded iron left by heading and rolling and leaves the geometry alone. On a partial-thread screw that matters for the shank as much as for the socket, because the shank is a fit and a coating would change it.
Where a plated version is used instead, both the socket and the shank are re-checked after plating. That is a different part with a different drawing, not a variation of this one, and on torx socket cap screws the difference shows up as a bit that will not seat.
Three assemblies where a cap head locates a part before it clamps it:
| Where it sits | The screw passes through a clearance hole in a jaw or a plate and threads into a fixed body, with the plain shank locating the part. |
| When it goes wrong | A fully threaded screw scores the clearance bore, and the part sits at an angle before the thread engages. |
| Why it happens | The parts are machined, the joint is set once, and the head is recessed. |
| What we control | Shank diameter and thread start checked, socket driven with the production bit. |
| Where it sits | The screw holds a guard or a panel on stainless equipment that is cleaned daily, where the shank locates the panel and the head sits flush in a recess. |
| When it goes wrong | A socket that traps residue is worse than a cross, and a plated screw sheds coating into the wash area. |
| Why it happens | The equipment is stainless, it is washed, and the joint is serviced. |
| What we control | Grade and passivation recorded, socket checked with the bit, thread gauged per batch. |
| Where it sits | The screw fixes a mount or a rail block where the shank acts as a locating pin and the head has to sit inside a bored recess. |
| When it goes wrong | A thread that starts too high lifts the mount off its seat, and a head that is too tall fouls the next component. |
| Why it happens | The face is machined, the fit is close, and the setting has to hold. |
| What we control | Shank diameter and thread start measured, head height checked against the bore. |
Four reasons that matter on a partial-thread socket cap screw, each tied to what the drawing has to prove:
|
Shank and thread start reviewed together
The shank diameter and length, the thread start and the head height are reviewed as one set, so a screw that would bind the clearance hole is raised first. Basis: Shank and thread start reviewed as one set. |
Head, socket and thread in one route
The cap head and the star socket are formed in one stroke, the shank is left plain, and the thread is rolled on the lower section. Basis: One route from wire to passivated screw. |
|
Shank and socket checked on the part
The plain shank is measured with a micrometer, the thread start from under the head, and the socket is driven with the production bit. Basis: First article measured on the shank. |
First article to repeat production
The first article fixes the drawing revision, wire heat, die set, thread roll and shank length; repeat orders are compared against that record. Basis: First article signed off before the batch is released. |
Shi Shi Tong forms these torx socket cap screws on a single-die header that upsets the cap head and punches the six-lobe socket in one stroke, leaves the under-head shank plain and rolls the machine thread on the lower section to a blunt chamfered end. The parts are cleaned and passivated. The first part of every run is measured on the head, the shank and the thread start, and driven with the production bit, before the batch continues.
|
|
The thread roll sets the shank. The rolls are trimmed to the thread length on the drawing, and changing that length means changing the rolls — so the thread start is fixed at the beginning of a run rather than adjusted while it runs. A torx socket cap screw with the wrong shank length is rejected at the first article, not corrected later.
What decides whether torx socket cap screws pass is the head, the shank, the socket, the thread start and the thread. 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 thread start is measured from under the head and cross-checked against the shank length, so the two numbers add up to the overall length. That is the check that catches a roll set for the wrong thread length, which on a partial-thread part is the failure that cannot be corrected.
The socket is checked by driving the first article at the joint torque with the production bit. On a plain stainless cap head the damage starts as a polish mark on a lobe flank, and that mark is what the inspection looks for before the bit actually slips.
Every shipment of torx socket 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 partial-thread screw the first article is fitted in the real joint, because the thread start only proves itself against the clearance hole it has to clear. 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 part is partial thread: a plain shank under the head and the thread on the lower section.
The plain shank passes a clearance hole and acts as a shoulder, so the joint locates before the thread engages. The thread start is a joint dimension.
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. The plain shank and the thread length are quoted separately, and the thread start from under the head.
It can, against another stainless thread or a worn bit. A dry film on the thread or a different alloy pairing are the usual answers.
Thread size and pitch, head diameter and height, socket size and depth, shank length, thread start and length, overall length and grade.
How a torx socket cap screw project runs from drawing to repeat delivery:
|
1
Send the drawing or sample
|
→ |
2
Shank and thread start review
|
→ |
3
First article fitted in the joint
|
→ |
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, shank length, thread start and length, overall length and stainless grade.
|
Thread and pitch
|
Head diameter and height
|
Socket size and depth
|
|
Shank length
|
Thread start
|
Overall length
|
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
